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The e-newsletter Marine Science Review compiles citations and abstracts of significant marine-related research, selected from more than 710 science journals. Each of its 12 subject areas, which include the range of important issues involving the intersection of human activity with coastal and marine environments, is distributed monthly. You can subscribe to each subject area individually or to all.

Marine Fauna and Flora: Marine and Coastal Birds

• Sea Ducks
• Shorebirds
• Seabirds

Sea Ducks

• Grecian, W.J., Inger, R., Attrill, M.J., Bearhop, S., Godley, B.J., Witt, M.J., and Votier, S.C.  Potential impacts of wave-powered marine renewable energy installations on marine birds.  Ibis 152(4): 683-697, 2010.
  Open Access >>  
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  One potential approach to combat the impacts of climate change is the expansion of renewable energy installations, leading to an increase in the number of wave-powered marine renewable energy installations (MREIs). The consequences of increased use of these devices for birds are unknown. Here we describe the wave-powered energy-generating devices currently either operational or in development and review the potential threats and benefits of these to marine birds, their habitats and prey. Direct negative effects include risk of collision, disturbance, displacement and redirection during construction, operation and decommissioning. Above-water collision is a particular concern with wind-powered devices, but, because of their low profiles, the collision risk associated with wave-powered devices is likely to be much lower. Conversely, wave devices also pose the novel threat of underwater collision. Wave-energy-generating devices may indirectly impact marine birds by altering oceanographic processes and food availability, with implications for trophic cascades. Through appropriate mitigation, wave-powered MREIs offer the potential to enhance habitats. Direct positive effects may include provision of roosting sites, and indirect positive effects may include prey aggregation due to suitable substrates for sessile organisms or because they act as de facto protected areas. The cumulative effect of these could be the improvement and protection of foraging opportunities for marine birds. Recent studies have been critical of the methods used in the assessment of wind-powered MREI impacts, which lack sufficient sample sizes, controls or pre-development comparisons. Here we suggest solutions for the design of future studies into the effects of MREIs. Wave-powered MREIs are certain to become part of the marine environment, but with appropriate planning, mitigation and monitoring they have the potential to offer benefits to marine birds in the future.

• Descamps, S., Forbes, M. R., Gilchrist, H. G., Love, O. P., and Bety, J.  Avian cholera, post-hatching survival and selection on hatch characteristics in a long-lived bird, the common eider Somateria mollisima.  Journal of Avian Biology 42(1): 39-48, 2011.
  Open Access >>  
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  Infectious diseases can have dramatic impacts on animal population dynamics, but how they influence vital rates remains understudied. We took advantage of the appearance of an avian cholera epizootic in an arctic colony of common eiders Somateria mollissima to study variation in juvenile survival and selection on hatch characteristics in relation to this highly infectious disease. Avian cholera is one of the most important infectious diseases affecting wild birds and is thought to primarily affect adult survival. Here, we show that avian cholera was associated with a 90% decline in duckling survival, leading to almost zero recruitment. Before the cholera outbreak, there was significant stabilizing selection on hatching date and significant positive directional selection on hatching mass. During cholera outbreaks, selection on hatch characteristics was no longer significant. These results were based on a low sample of surviving ducklings in cholera years, but suggested that date and mass at hatching did no longer affect duckling survival in the presence of cholera. These effects of avian cholera on post-hatching survival were likely not only the consequence of the disease per se, but also a consequence of an increase in predation rates that followed the emergence of avian cholera. Our results emphasize the dramatic direct and indirect impacts that infectious disease can have on vital rates, and thus population dynamics.

• Merkel, F.R.  Evidence of recent population recovery in common eiders breeding in western Greenland.  Journal of Wildlife Management 74(8): 1869-1874, 2010. 
  Read Abstract >>

  Severe population declines were reported for common eiders (Somateria mollissima) in western Greenland over the period 1960-2000. A monitoring program, concurrent with more restrictive hunting regulations on common eiders, revealed breeding numbers increasing by 212%, from 2,558 active nests in 2000 to 7,982 nests in 2007. Though it was not possible to directly link harvest reduction and population growth in West Greenland, a similar increase in breeding numbers in Canada was correlated with the harvest reduction in Greenland and linked to increasing adult survival and recruitment of first-time breeders, and a similar explanation is suggested for West Greenland. The study emphasizes that appropriate restrictions in hunting can be efficient in wildlife management and that common eiders can sustain dramatic rates of increase during population regrowth. It also shows that cost-efficient monitoring programs can be established through cooperation with local residents.

• Wilson, L.K., Harris, M.L., Trudeau, S., Ikonomou, M.G., and Elliott, J.E.  Properties of blood, porphyrins, and exposure to legacy and emerging persistent organic pollutants in surf scoters (Melanitta perspicillata) overwintering on the south coast of British Columbia, Canada.  Archives of Environmental Contamination and Toxicology 59(2): 322-333, 2010. 
  Read Abstract >>

  The surf scoter (Melanitta perspicillata) is a little-studied species of North American sea duck. Estimates suggest it has experienced a precipitous decline in breeding numbers over the latter half of the past century. To investigate the potential role of contaminant uptake and toxicity in the population decline, this study undertook to measure blood chemistry, porphyrin concentrations, EROD, and organic contaminants in mature surf scoters wintering in the Strait of Georgia, BC, Canada. Hepatic organochlorine pesticide, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, polychlorinated biphenyl (PCB), polybrominated diphenyl ether, and nonylphenol concentrations were relatively low; for example, STEQs pound (toxic equivalents) for PCBs, dioxins, and furans combined ranged from 4.7 ng/kg wet weight in reference-site (Baynes Sound) birds to 11.4 ng/kg wet weight in birds from Vancouver Harbour. Nonetheless, elevated EROD activity indicated that birds in Howe Sound were responding to an Ah-receptor-mediated stressor, which was also affecting hematocrit values and possibly vitamin A status. In addition, a low proportion of lymphocytes in individuals across locations in early spring samples was associated with poor body condition. The apparent loss of fitness just prior to the onset of northerly migrations to breeding grounds is of particular concern. Compromised health of mature birds at this point in the season might impact negatively on the productivity and survival of some individuals, particularly those overwintering in Howe Sound.

• Iverson, S.A. and Esler, D.  Harlequin Duck population injury and recovery dynamics following the 1989 Exxon Valdez oil spill.  Ecological Applications 20(7): 1993-2006, 2010. 
  Read Abstract >>

  The 1989 Exxon Valdez oil spill caused significant injury to wildlife populations in Prince William Sound, Alaska, USA. Harlequin Ducks (Histrionicus histrionicus) were particularly vulnerable to the spill and have been studied extensively since, leading to one of the most thorough considerations of the consequences of a major oil spill ever undertaken. We compiled demographic and survey data collected since the spill to evaluate the timing and extent of mortality using a population model. During the immediate aftermath of the spill, we estimated a 25% decrease in Harlequin Duck numbers in oiled areas. Survival rates remained depressed in oiled areas 6-9 years after the spill and did not equal those from unoiled areas until at least 11-14 years later. Despite a high degree of site fidelity to wintering sites, immigration was important for recovery dynamics, as the relatively large number of birds from habitats outside the spill zone provided a pool of individuals to facilitate numerical increases. On the basis of these model inputs and assumptions about fecundity rates for the species, we projected a timeline to recovery of 24 years under the most-likely combination of variables, with a range of 16 to 32 years for the best-case and worst-case scenarios, respectively. Our results corroborate assertions from other studies that the effects of spilled oil on wildlife can be expressed over much longer time frames than previously assumed and that the cumulative mortality associated with chronic exposure to residual oil may actually exceed acute mortality, which has been the primary concern following most oil spills.

• Schwemmer, P., Mendel, B., Sonntag, N., Dierschke, V., and Garthe, S.  Effects of ship traffic on seabirds in offshore waters: implications for marine conservation and spatial planning.  Ecological Applications 21(5): 1851-1860, 2011. 
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  Most anthropogenic influences on marine ecosystems, except for river- or terrestrial-borne pollution, involve some sort of vessel activity. Increasing anthropogenic activities mean that many countries are being forced to develop spatial planning schemes, while at the same time implementing conservation sites for sensitive species at sea. The effects of ship traffic on seabirds sensitive to human disturbance are currently too poorly understood to allow for the development of proper planning and conservation guidelines. We therefore used aerial surveys and experimental disturbance to elucidate the effects of passing ships on the distribution patterns, habitat loss, and species-specific flight reactions of birds, as well as the potential for habituation. Loons (Gavia spp.) showed clear avoidance of areas with high shipping intensity. Flush distances of four sea duck species differed significantly, with the longest distances recorded for Common Scoters (Melanitta nigra) and the shortest for Common Eiders (Somateria mollissima). Flush distance was positively related to flock size. Among all the sea duck species studied, the duration of temporary habitat loss was longest for Common Scoters. We found indications of habituation in sea ducks within areas of channeled traffic. However, it is questionable if habituation to free-ranging ships is likely to occur, because of their unpredictable nature. We therefore recommend that spatial planning should aim to channel ship traffic wherever possible to avoid further habitat fragmentation and to allow for habituation, at least in some species. Information on the effects of shipping on other seabird species and during different periods of the year is urgently needed, together with information on the effects of different types of boats, including recreational and fishing vessels.

• Burger, J., Gordon, C., Lawrence, J., Newman, J., Forcey, G., and Vlietstra, L.  Risk evaluation for federally listed (roseate tern, piping plover) or candidate (red knot) bird species in offshore waters: A first step for managing the potential impacts of wind facility development on the Atlantic Outer Continental Shelf.  Renewable Energy 36(1): 338-351, 2011. 
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  With a worldwide increase in attention toward developing a reliance on renewable energy, there is a need to evaluate the effects of these facilities (solar, wind, hydropower) on ecosystems. We conduct a hazard and risk evaluation for three species of birds that are listed, or candidates for listing, as federally threatened or endangered in the US, and that might occur offshore on the Atlantic Outer Continental Shelf (AOCS) where wind power facilities could be developed. Our objectives were to: 1) provide conceptual models for exposure for each species, and 2) examine potential exposure and hazards of roseate tern (Sterna dougallii) and piping plover (Charadrius melodus, both federally endangered in the US) and red knot (Calidris canutus rufa, candidate species) in the AOCS. We used a weight-of-evidence approach to evaluate information from a review of technical literature. We developed conceptual models to examine the relative vulnerability of each species as a function of life stage and cycle (breeding, staging, migratory, wintering). These methods are useful for conducting environmental assessments when empirical data are insufficient for a full risk assessment. We determined that 1) Roseate terns are likely to be exposed to risk during the migratory and breeding season when they occur in the AOCS, as well as while staging. 2) Piping plovers are not likely to be at risk during the breeding season, but may be at risk during spring or fall migrations. Risk to this species is likely to be low from turbines located far from land as this species migrates mainly along the coast. 3) Red knots are potentially exposed to some risk during migration, especially long-distance migrants whose migratory routes take them over the AOCS. More information is required on exact spatio-temporal migration routes, flight altitudes (especially during ascent and descent), and behavioral avoidance of turbines by birds to ascertain their risk.

Shorebirds

• Rogers, D.I., Yang, H.Y., Hassell, C.J., Boyle, A.N., Rogers, K.G., Chen, B., Zhang, Z.W., and Piersma, T.  Red Knots (Calidris canutus piersmai and C. c. rogersi) depend on a small threatened staging area in Bohai Bay, China.  Emu 110(4): 307-315, 2010.
  Open Access >>  
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  We monitored numbers of Red Knots (Calidris canutus) staging in Bohai Bay, China (39º02'N, 118º15'E) on northward migration. Knots were identified to subspecies, and we systematically searched for colour-banded birds from the non-breeding grounds. We modelled migratory turnover, and revised estimates of flyway population using recently published counts from the non-breeding grounds. Two Russian-breeding subspecies occurred at our study site: C. c. rogersi (migrating to Chukotka), and C. c. piersmai (migrating to the New Siberian Islands); they co-occur on non-breeding grounds in Australia and New Zealand, but differ markedly in timing of migration. We conservatively estimate that our study site, comprising only 20 km of coastline, was used by over 45% of the combined world population of adult C. c. rogersi and C. c. piersmai – a conclusion supported by the independent data on frequency of resighting of colour-banded birds from north-western Australia and New Zealand. Much of this vital staging area is now being destroyed through construction of the Caofedian Industrial Zone and more westerly developments, which comprise only some of the many tidal flat 'reclamation' projects in the region. Preservation of the remaining tidal flats of Bohai Bay is essential to the conservation of Red Knots in the East Asian-Australasian Flyway.

• Erwin, R.M., Brinker, D.F., Watts, B.D., Costanzo, G.R., and Morton, D.D.  Islands at bay: rising seas, eroding islands, and waterbird habitat loss in Chesapeake Bay (USA).  Journal of Coastal Conservation 15(1): 51-60, 2011. 
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  Like many resources in the Chesapeake Bay region of the U.S., many waterbird nesting populations have suffered over the past three to four decades. In this study, historic information for the entire Bay and recent results from the Tangier Sound region were evaluated to illustrate patterns of island erosion and habitat loss for 19 breeding species of waterbirds. Aerial imagery and field data collected in the nesting season were the primary sources of data. From 1993/1994 to 2007/2008, a group of 15 islands in Tangier Sound, Virginia were reduced by 21% in area, as most of their small dunes and associated vegetation and forest cover were lost to increased washovers. Concurrently, nesting American black ducks (Anas rubripes) declined by 66%, wading birds (herons-egrets) by 51%, gulls by 72%, common terns (Sterna hirundo) by 96% and black skimmers (Rynchops niger) by about 70% in this complex. The declines noted at the larger Bay-wide scale suggest that this study area maybe symptomatic of a systemic limitation of nesting habitat for these species. The island losses noted in the Chesapeake have also been noted in other Atlantic U.S. coastal states. Stabilization and/or restoration of at least some of the rapidly eroding islands at key coastal areas are critical to help sustain waterbird communities.

• van de Pol, M., Ens, B.J., Heg, D., Brouwer, L., Krol, J., Maier, M., Exo, K.M., Oosterbeek, K., Lok, T., Eising, C.M., and Koffijberg, K.  Do changes in the frequency, magnitude and timing of extreme climatic events threaten the population viability of coastal birds?  Journal of Applied Ecology 47(4): 720-730, 2010. 
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  1. Climate change encompasses changes in both the means and the extremes of climatic variables, but the population consequences of the latter are intrinsically difficult to study. 2. We investigated whether the frequency, magnitude and timing of rare but catastrophic flooding events have changed over time in Europe's largest estuary. Subsequently, we quantified how this has affected the flooding risk of six saltmarsh nesting bird species. 3. We show that maximum high tide has increased twice as fast as mean high tide over the past four decades (0·8 vs. 0·4 cm year^-1), resulting in more frequent and more catastrophic flooding of nests, especially around the time when most eggs have just hatched. 4. Using data on species' nest elevations, on their timing of egg-laying and on the duration that their eggs and chicks are at risk from flooding, we show that flooding risks increased for all six studied species (even after accounting for compensatory land accretion) and this is expected to worsen in the near future if they do not adapt. Moreover, our study provides the first evidence that increasing flooding risks have reduced the reproductive output below stable population levels in at least one species, the Eurasian oystercatcher Haematopus ostralegus. 5. Sensitivity analyses show that currently birds would benefit most from adapting their nest-site selection to higher areas. However, historically the lower marsh has been favoured for its proximity to the feeding grounds and for its low vegetation aiding predator detection. 6. Synthesis and applications. We argue that it is more difficult for birds to infer that habitat quality has decreased from changes in the frequency of rare and unpredictable extreme events than from trends in climatic means. Consequently, at present the lower parts of the saltmarsh may function as an ecological trap. The creation of new (i.e. low) saltmarshes – currently a restoration priority – may thus counteract the goal of increasing the avian biodiversity of an area. Management tools to mitigate the effects of climate change, either by making the higher saltmarsh more attractive (mowing, predator control) or by reducing the flooding risk of the lower marsh (building elevated plots), await to be tested.

• Hu, J.H., Hu, H.J., and Jiang, Z.G.  The impacts of climate change on the wintering distribution of an endangered migratory bird.  Oecologia 164(2): 555-565, 2010. 
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  There is now ample evidence of the effects of anthropogenic climate change on the distribution and abundance of species. The black-faced spoonbill (Platalea minor) is an endangered migratory species and endemic to East Asia. Using a maximum entropy approach, we predicted the potential wintering distribution for spoonbills and modeled the effects of future climate change. Elevation, human influence index and precipitation during the coldest quarter contributed most to model development. Five regions, including western Taiwan, scattered locations from eastern coastal to central mainland China, coastal areas surrounding the South China Sea, northeastern coastal areas of Vietnam and sites along the coast of Japan, were found to have a high probability of presence and showed good agreement with historical records. Assuming no limits to the spread of this species, the wintering range is predicted to increase somewhat under a changing climate. However, three currently highly suitable regions (northeastern Vietnam, Taiwan and coastal areas surrounding the South China Sea) may face strong reductions in range by 2080. We also found that the center of the predicted range of spoonbills will undergo a latitudinal shift northwards by as much as 240, 450, and 600 km by 2020, 2050 and 2080, respectively. Our findings suggest that species distribution modeling can inform the current and future management of the black-faced spoonbill throughout Asia. It is clear that a strong international strategy is needed to conserve spoonbill populations under a changing climate.

• Seavey, J.R., Gilmer, B., and McGarigal, K.M.  Effect of sea-level rise on piping plover (Charadrius melodus) breeding habitat.  Biological Conservation 144(1): 393-401, 2011.
  Open Access >>  
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  Climate change is raising sea levels, threatening many low-lying coastal areas and associated wildlife. We assessed the threat of sea-level rise (SLR) to the breeding habitat of the federally threatened piping plover on the barrier islands of Suffolk County, New York. We determined the extent of habitat change over the next 100 years under several SLR estimates, as well as the interactive effects of coastal development and storm surge. We found that if plover habitat cannot migrate, SLR is likely to reduce breeding areas. However, if habitat is able to migrate upslope and inland, breeding areas could actually increase with SLR. Unfortunately, this potential habitat gain is stymied by human development, which we found to reduce migrating habitat by 5-12%, depending on SLR estimates. We also found that the spatial configuration of developed areas mattered more than intensity of development in blocking the migration of potential habitat area. Our results raise concern over the likelihood of increased conflict between plover habitat protection and human recreation as habitat is likely to become a larger proportion of the barrier islands in the future. Finally, our results highlight risk from the synergism between SLR and coastal storms, as we estimate that a large hurricane could flood up to 95% of plover habitat. To assure the future of plover habitat on these barrier islands, management needs to promote natural overwash and habitat migration, while minimizing development adjacent to future breeding habitat.

• Sripanomyom, S., Round, P.D., Savini, T., Trisurat, Y., and Gale, G.A.  Traditional salt-pans hold major concentrations of overwintering shorebirds in Southeast Asia.  Biological Conservation 144(1): 526-537, 2011.
  Open Access >>  
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  Shorebirds are declining worldwide due to loss and degradation of critical breeding and wintering habitats. Some human-modified habitats, particularly salt-pans which are used by shorebirds in many regions of the world, may help substitute for natural habitats lost for a wide range of species during migration. We studied the influence of landscape characteristics on species richness, abundance, and diversity of shorebirds at 20 sites covering most of the Inner Gulf of Thailand, a landscape with a long history of salt farming. Sites with salt-pans present held significantly higher species richness, abundance and diversity of shorebirds. Areas with larger proportions given over to aquaculture tended to have lower species richness, abundance and diversity. Generalized additive models indicated that landscapes with a larger proportion of tidal flats in conjunction with salt-pans were the best predictors of sites with higher species richness, abundance and diversity. Landscape configurations with higher richness, abundance and diversity of shorebirds also tended to be less fragmented and contained slightly larger patches. Shorebirds appeared to use ponds with exposed mud in salt-pans as both roosting sites and supplementary feeding grounds during high tide. Traditional salt-pans therefore proved to contribute significantly to maintenance of overwintering shorebird populations in this landscape and should be investigated elsewhere in Asian coastal zones. Collaboration between researchers, salt farmers and planning authorities as to how best to maintain salt-pans as potential shorebird roost sites such as in the Inner Gulf of Thailand is urgently needed in order to maintain habitat for shorebird populations in critical wintering and staging areas of this flyway.

• Karpanty, S.M., Cohen, J., Fraser, J.D., and Berkson, J.  Sufficiency of horseshoe crab eggs for red knots during spring migration stopover in Delaware Bay USA.  Journal of Wildlife Management 75(5): 984-994, 2011. 
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  Horseshoe crab (Limulus polyphemus) eggs are a dietary staple of the red knot (Calidris canutus) during its spring stopover on the Delaware Bay. Numbers of knots stopping in Delaware Bay declined in the 1990s concurrent with a decline in horseshoe crabs, leading to the hypothesis that reduced horseshoe crab egg abundance limited the red knot population. Management efforts, including a seasonal harvest moratorium in the Delaware Bay, have been instituted to restore crab populations to levels of sustainable use by multiple users, including migratory birds. Our objective was to evaluate the sufficiency of horseshoe crab eggs in Delaware Bay in May-June 2004 and 2005 for knots to refuel for their migratory flight to the Arctic breeding grounds. We examined egg counts to determine if there were fewer high egg-density sites later than earlier in the day and season, as migrating birds might deplete this resource. We studied foraging rates at red knot locations to determine if foraging probes increased with time of day and season as birds depleted surface eggs by pecking, then began probing for subsurface eggs. Finally, we experimentally tested whether red knots and their competitors depleted horseshoe crab eggs. Crab egg numbers at knot foraging sites did not decline throughout the day or season in 2004. In both years, we found no evidence that knots switched from pecking to probing with increases in time since sunrise or start of the stopover. Egg numbers were similar in exclosed and accessible plots on crab nesting depressions and in areas of open intertidal zone, but were significantly lower in accessible than in exclosed plots in the wrack line. Our results indicate that horseshoe crab eggs in Delaware Bay were sufficient to support the refueling of the present-day stopover population of red knots. If an increase in the availability of crab eggs to foraging birds does not result in an increase in knot numbers, managers must prioritize mitigation of limiting factors at other historically important spring stopovers and on the poorly understood breeding and wintering grounds in addition to the Delaware Bay.

• Kraan, C., van Gils, J.A., Spaans, B., Dekinga, A., and Piersma, T.  Why Afro-Siberian Red Knots Calidris canutus canutus have stopped staging in the western Dutch Wadden Sea during southward migration.  Ardea 98(2): 155-160, 2010. 
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  Afro-Siberian Red Knots Calidris canutus canutus use the western Dutch Wadden Sea as a refuelling area during southward migration from Taimyr to West Africa. Here we document the decline of their food stocks in this area, based on a yearly large-scale benthic mapping effort, from 1996 to 2005. For each benthic sampling position, intake rate (mg/s, ash-free dry mass) was predicted by an optimal diet model based on digestive rate maximization. Over the ten years, when accounting for a threshold value to meet energetic fuelling demands, subspecies canutus lost 86% of its suitable foraging area. Over this period, the proportion of probable canutus in mist-net catches in July-August declined relative to overwintering islandica Knots. This suggests that canutus dropped even more in numbers than islandica, for which we showed earlier a food-explained decline in numbers. We discuss the possible causality between a decline in the quality of intertidal mudflats in the Dutch Wadden Sea and population declines of Knots in the West-African wintering quarters.

• Gratto-Trevor, C.L. and Abbott, S.  Conservation of Piping Plover (Charadrius melodus) in North America: science, successes, and challenges.  Canadian Journal of Zoology 89(5): 401-418, 2011.
  Open Access >>  
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  There are only about 8000 Piping Plovers (Charadrius melodus Ord, 1834) in existence. Because they depend on environments that are under intense human pressures and controls in both their breeding and wintering grounds, these birds and their habitats are highly managed in many areas across their range. Efforts to recover this endangered and threatened species have engaged thousands of people from Newfoundland to the Caribbean, and have provoked a ground-swell of public support and, at times, fury, as well as a considerable body of research. Although populations have increased substantially in the U.S. Atlantic and U.S. Great Lakes, this is not true of all regions. Significant issues still exist with respect to the efficacy of predator management; need for more accurate model input information; effects of climate, pollutants, and water management; habitat loss and degradation from recreation and development; and whether the cost and effort of management for this species can be maintained or increased where needed.

• Maguire, G.S., Duivenvoorden, A.K., Weston, M.A., and Adams, R.  Provision of artificial shelter on beaches is associated with improved shorebird fledging success.  Bird Conservation International 21(2): 172-185, 2011. 
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  Artificial chick shelters might improve productivity of beach-nesting birds threatened by anthropogenic disturbance. We investigated the efficacy of three different chick shelter designs against four criteria: accessibility to chicks over time, thermal insulation, conspicuousness to beach-goers, and practicality (cost and ease of transport). One design ('A-frame') was selected because it offered the greatest thermal insulation, was the least conspicuous, most cost effective, and performed equally well in terms of accessibility. We deployed these artificial shelters on Hooded Plover Thinornis rubricollis territories where broods were present (n = 11), and compared the behaviour and survival rate of chicks to that at control sites (n = 10). We were unable to discern any difference in the behaviour of broods when artificial shelters were available. However, the survival rate of chicks to fledging was 71.8% higher where an artificial shelter was provided (n = 21 broods). This was validated by analysing data from a larger sample of broods monitored as part of an active volunteer-based management programme; shelters conferred a 42.8% increase in survival to fledging (n = 81 broods). Thus, artificial shelters have the potential to increase survival rates of threatened shorebird chicks, though the mechanisms through which survival is increased require further investigation.

Seabirds

• Jones, A.W., Dalton, C.M., Stowe, E.S., and Post, D.M.  Contribution of declining anadromous fishes to the reproductive investment of a common piscivorous seabird, the double-crested cormorant (Phalacrocorax auritus).  Auk 127(3): 696-703, 2010.  
  
• Phillips, R.A.  Eradications of invasive mammals from islands: why, where, how and what next?  Emu 110(4): I-VII, 2010.
  Open Access >> 
  
• Chambers, L.E., Devney, C.A., Congdon, B.C., Dunlop, N., Woehler, E.J., and Dann, P.  Observed and predicted effects of climate on Australian seabirds.  Emu 111(3): 235-251, 2011. 
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  Although there is growing evidence of climate warming, for many regions the broader effects of climate variation on marine top predators remains unknown owing to the difficulty in obtaining, for synthesis, long-term and short-term datasets on multiple species. In the Australian region, climatic and oceanographic variability and change have been shown to affect marine species, often with profound consequences. Many seabirds are apex predators for which changes in climatic and oceanic dynamics have driven range movements poleward, reduced breeding success and altered breeding timing for some species. Here we review the literature to assess and determine the vulnerability of Australian seabirds to variation and change in climate and identify which species and ecosystems may be more resilient to future climate warming. It is clear from this synthesis that not all Australian seabirds are affected similarly, with responses varying by species and location. In addition, the paucity of information on the distribution and biology of seabird prey, foraging patterns and movements of seabirds, and the ability of seabirds to switch between prey species or adjust timing of life-cycles make generalisations about potential effects of future climate change and adaptive capacity in seabirds difficult. This applies both within Australia and elsewhere, where data are similarly sparse.

• Pyle, P., Welch, A.J., and Fleischer, R.C.  A new species of shearwater (Puffinus) recorded from Midway Atoll, Northwestern Hawaiian Islands.  Condor 113(3): 518-527, 2011. 
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  Small black-and-white shearwaters of the genus Puffinus are distributed globally, and their phylogenetic relationships are complex and uncertain. In 1963 a small shearwater collected at Midway Atoll in the North Pacific Ocean was identified as a Little Shearwater (P. assimilis), but several physical features suggest closer alliance with Audubon's Shearwater (P. lherminieri) and its relatives. Biometrics indicate that the taxon this specimen represents is smaller than any other known shearwater, and phylogenetic analyses indicate it is distinct, with a pair-wise sequence divergence of at least 3.8% from related taxa. We thus propose a new species based on the specimen: Bryan's Shearwater (Puffinus bryani nom. nov.). The breeding and nonbreeding ranges of Bryan's Shearwater are unknown, but a physical resemblance to the North Atlantic boydi (of controversial taxonomic status within Puffinus) suggests an affiliation with subtropical or tropical waters. Bryan's Shearwater is apparently rare and could be threatened by extinction; therefore, additional information is needed to increase our understanding of this taxon and its conservation requirements.

• Wagner, E.L. and Boersma, P.D.  Effects of fisheries on seabird community ecology.  Reviews in Fisheries Science 19(3): 157-167, 2011. 
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  Significant depletions of marine fish populations due to overfishing are becoming more and more common. Such depletions have serious consequences not only for the fished species, but also for those organisms that depend on them for food. For seabirds, in particular, the effects of fisheries can be felt via a number of pathways. However, few studies have considered those effects in terms of seabird community ecology. In this review, seabirds were separated into three functional groups based on their primary foraging strategy when they are likely to interact with fishing vessels: kleptoparasites, scavengers, and pursuit-divers. Theoretical effects webs were built for three different gear types: gillnets, longlines, and trawlers. For kleptoparasites and scavengers, to trail a fishing vessel exacts a cost but also confers a benefit; they are occasionally killed by fishing gear, but a potentially reliable food source may outweigh that risk. Also, the costs and benefits are direct. In contrast, pursuit-divers do not benefit from fisheries nearly as much and bear both direct and indirect costs -- direct in that divers are caught in fishing gear, and indirect in that discards may lead to increases in populations of kleptoparasites and scavengers, which prey on pursuit-divers, their eggs, and their young at breeding colonies.

• Tuck, G.N.  Are bycatch rates sufficient as the principal fishery performance measure and method of assessment for seabirds?  Aquatic Conservation: Marine and Freshwater Ecosystems 21(5): 412-422, 2011. 
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  1. Seabird bycatch in oceanic and coastal fisheries is believed to be the principal cause of the population declines that have been observed for many seabird populations. Pelagic and demersal longline and trawl operations have been implicated in these declines. 2. Many government and national fishery bodies have environmental and fishery legislation that requires fisheries to be managed in a manner that is not harmful to non-target species, including seabirds. A common tool for measuring the impact of a fishery on incidentally caught seabirds is an estimate of the bycatch rate. Unfortunately, the estimation and interpretation of bycatch rates is not trivial and is complicated by poor observer coverage, under-reporting of bycatch and data lacking species specificity. 3. In this paper, a stochastic simulation model of two seabird populations affected by a single fishing fleet is presented. The model is used to explore the consequences of applying a bycatch rate management control rule to assess and manage the fishery's incidental mortality of seabirds. Comparisons are also made with values derived from Potential Biological Removal (PBR) theory. 4. Results conclude that using bycatch rates as a measure to assess performance of the fishery and to reduce bycatch is, under many circumstances, not sufficient to achieve conservation goals. Bycatch rates can be within the limit recommended by management, giving the impression that the fishery has reduced bycatch to sustainable levels, when in fact the low rates are due to the populations having collapsed. 5. The interpretation of bycatch rates, and any subsequent bycatch rate management rules, needs to be considered with respect to changes in fishing effort, to population-specific impacts, to levels of compliance, and to the robustness of the bycatch rate estimate. Simply applying a bycatch rate control rule without caution can lead to catastrophic results for incidentally caught populations of seabirds.

• Brothers, N., Duckworth, A.R., Safina, C., and Gilman, E.L.  Seabird bycatch in pelagic longline fisheries is grossly underestimated when using only haul data.  PLoS ONE 5(8): art. e12491, 2010.
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  Hundreds of thousands of seabirds are killed each year as bycatch in longline fisheries. Seabirds are predominantly caught during line setting but bycatch is generally recorded during line hauling, many hours after birds are caught. Bird loss during this interval may lead to inaccurate bycatch information. In this 15 year study, seabird bycatch was recorded during both line setting and line hauling from four fishing regions: Indian Ocean, Southern Ocean, Coral Sea and central Pacific Ocean. Over 43,000 albatrosses, petrels and skuas representing over 25 species were counted during line setting of which almost 6,000 seabirds attempted to take the bait. Bait-taking interactions were placed into one of four categories. (i) The majority (57%) of bait-taking attempts were "unsuccessful" involving seabirds that did not take the bait nor get caught or hooked. (ii) One-third of attempts were "successful" with seabirds removing the bait while not getting caught. (iii) One-hundred and seventy-six seabirds (3% of attempts) were observed being "caught" during line setting, with three albatross species – Laysan (Phoebastria immutabilis), black-footed (P. nigripes) and black-browed (Thalassarche melanophrys) – dominating this category. However, of these, only 85 (48%) seabird carcasses were retrieved during line hauling. Most caught seabirds were hooked through the bill. (iv) The remainder of seabird-bait interactions (7%) was not clearly observed, but likely involved more "caught" seabirds. Bait taking attempts and percentage outcome (e.g. successful, caught) varied between seabird species and was not always related to species abundance around fishing vessels. Using only haul data to calculate seabird bycatch grossly underestimates actual bycatch levels, with the level of seabird bycatch from pelagic longline fishing possibly double what was previously thought.

• Barcelona, S.G., Ortiz de Urbina, J.M., de la Serna, J.M., Alot, E., and Macías, D.  Seabird bycatch in Spanish Mediterranean large pelagic longline fisheries, 2000-2008.  Aquatic Living Resources 23(4): 363-371, 2010. 
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  Incidental catch or bycatch represents a significant threat for the conservation of seabird populations. The western Mediterranean is an important fishing area where the Spanish pelagic and semi-pelagic longline fleet targeting swordfish (Xiphias gladius), bluefin tuna (Thunnus thynnus) and albacore (Thunnus alalunga) operates. Bycatch of these fisheries includes several seabird species. Given the importance of conservation of the bycatch species (marine mammals, turtles, sharks and seabirds), an on-board observer program was implemented by the Spanish Oceanographic Institute (IEO); this included collecting data on effort and catch, as well as weight and number of individuals of the main bycatch species. The aim of the present study is to report data on seabird bycatch collected by the on-board observer program of the IEO in the Western Mediterranean. Data on seabird bycatch were collected for the period 2000-2008, throughout the year. Six longline gears targeting large pelagic fish were identified operating in the area of study, but only three had an effect on seabird species. Differences in catch per unit effort (CPUE, birds per 1000 hooks) for each gear, as well as their effect on particular seabird species, are reported in this study. A total of 4 786 466 hooks were monitored, which yielded 182 seabirds belonging to 7 different species. The average CPUE for the studied period was 0.038 birds per 1000 hooks. Cory's shearwater (Calonectris diomedea) and yellow-legged gull (Larus michahellis) were the species the most highly represented in the catch. In contrast, Balearic shearwater (Puffinus mauretanicus) was only present in the longline fishery targeting albacore (CPUE = 0.005 birds per 1000 hooks). Our results suggest that Cory's shearwater is the species the most affected by the longline fishery in the Western Mediterranean, probably due to its biological characteristics, and corroborate the well-established downward trend in its population.

• Laneri, K., Louzao, M., Martinez-Abrain, A., Arcos, J.M., Belda, E.J., Guallart, J., Sanchez, A., Gimenez, M., Maestre, R., and Oro, D.  Trawling regime influences longline seabird bycatch in the Mediterranean: new insights from a small-scale fishery.  Marine Ecology Progress Series 420: 241-252, 2010. 
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  Unintended mortality in longlines emerged in the early 1990s as one of the most important threats for pelagic seabirds worldwide. Most of the studies were focused on highly developed industrial fisheries, overlooking bycatch in small-scale artisanal fisheries. However, bycatch in small-scale fisheries might have negative effects similar to those of industrial fisheries when they overlap with hotspot areas of top predators. Moreover, different types of fishing gear coexist in the same oceanographic area, particularly in highly exploited marine ecosystems such as the western Mediterranean. We quantify for the first time the influence of trawling regime on Cory's shearwater Calonectris diomedea bycatch in the western Mediterranean longline artisanal fishery. The availability of trawling discards has substantial influence on the foraging and breeding ecology of many seabirds, and trawling inactivity may drive shearwaters to seek alternative food resources, such as baits used in longline fishing. Based on our previous knowledge of the system, we also tested other variables affecting bycatch over 8 yr (1998 to 2005). Within this 2-fishery framework, we found that trawling regime, longline fishing time and breeding stage were key factors explaining shearwater attendance to longline vessels, but mainly trawling regime and fishing time increased the incidental capture of Cory's shearwaters. More specifically, during the pre-breeding and chick-rearing periods, bycatch dramatically increased during sunrise sets in the absence of trawling activity. Importantly, this study indicates the need for an integrated multi-fisheries management approach for the conservation of seabirds and highlights the necessity of banning longline fishing during periods of trawling inactivity.

• Favero, M., Blanco, G., Garcia, G., Copello, S., Pon, J.P.S., Frere, E., Quintana, F., Yorio, P., Rabuffetti, F., Canete, G., and Gandini, P.  Seabird mortality associated with ice trawlers in the Patagonian shelf: effect of discards on the occurrence of interactions with fishing gear.  Animal Conservation 14(2): 131-139, 2011. 
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  This study investigated the level of seabird mortality caused by the domestic trawl fleet (freshies) for hake (among other less important targets) operating in waters off central Patagonia (37-48ºS), analyzing the effect of environmental and operational variability on the level of seabird interactions. With a total of 135 vessels, the fleet is one of the largest in Argentina. Specifically tasked seabird observers were placed onboard trawlers during the summer and winter seasons of the years 2006 and 2007. The type and number of seabird interactions (i.e. contacts with fishing gear) were recorded during shooting and hauling operations, covering 72 days of observation and 328 trawls. Black-browed albatrosses, white-chinned petrels Procellaria aequinoctialis, southern giant petrels Marconectes giganteus and southern royal albatrosses Diomedea epomophora were the most abundant species interacting with trawlers. Confirmed mortalities of black-browed and southern royal albatrosses were the result of collisions and entanglement with the warp cable while birds were scavenging. The estimated total mortality rate was 0.017 birds h^-1 and 0.105 birds per vessel per day. The intensity of interactions (in terms of the number of contacts per unit time) was largely explained by the distribution of the fishing effort. Seasonality and the incidence of discards were the strongest factors explaining the occurrence of seabird interactions. The total annual mortality in the trawl fleet under investigation was roughly estimated to be from several hundred to over a thousand albatrosses. However, these figures should be considered preliminary due to the limited spatial and temporal coverage of data and the fact that estimations were based on a low number of observed mortalities. The implementation of a strategic discard management may significantly reduce the number of seabird mortalities from collisions with warp cables or improve the effectiveness of other complementary mitigation methods. Urgent implementation of mitigation measures is needed in this fleet to reduce the mortality of albatrosses and petrels along the Patagonian shelf.

• Trebilco, R., Gales, R., Lawrence, E., Alderman, R., Robertson, G., and Baker, G.B.  Characterizing seabird bycatch in the eastern Australian tuna and billfish pelagic longline fishery in relation to temporal, spatial and biological influences.  Aquatic Conservation: Marine and Freshwater Ecosystems 20(5): 531-542, 2010. 
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  1. Seabirds killed incidentally in Australia's eastern tuna and billfish (ETBF) longline fishery between September 2001 and June 2006 were examined to evaluate species composition and to relate, where possible, capture events to operational and environmental factors. 2. During this period 2.129 million hooks on 2202 shots were observed, and 369 birds were reported killed. The majority (78%) of these were flesh-footed shearwaters (Puffinus carneipes), 53% of which were male and 44% female. Smaller numbers of medium to large sized albatrosses (Diomedeidae, predominantly female) and other shearwaters (Puffinus spp.) and petrels (Pterodroma spp.) dominated the remainder of the bycatch. 3. Of the 369 birds reported taken as bycatch, 280 were available for necropsy, and species identifications performed in situ by observers were assessed. While observer identifications were generally correct for common species, performance was poor for less common ones. 4. The geographical location (latitude) of shots, season, time of day at which shots were set, and bait type and life status (dead or alive) influenced the seabird bycatch rate. The majority of captures (87% overall) occurred between 30 and 35ºS, with bycatch being lowest in winter, and remaining at similar levels across the other seasons. 5. The use of live fish bait was generally associated with increased captures of both seabirds overall, and flesh-footed shearwaters in particular.

• Løkkeborg, S.  Best practices to mitigate seabird bycatch in longline, trawl and gillnet fisheries – efficiency and practical applicability.  Marine Ecology Progress Series 435: 285-303, 2011.
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  Growing concerns have been raised about incidental capture of seabirds in various fisheries. Here, studies testing measures to prevent seabird bycatch in longline, trawl and gillnet fisheries are reviewed in order to identify the most efficient mitigation methods. There is potential for considerable reduction in mortality rates in most longline fisheries because effective measures have been developed. However, there is no single solution as the efficiency of a measure is specific to each fishery. In demersal longline fisheries where northern fulmar is the dominant seabird captured, streamer lines have been proven to virtually eliminate mortality. In the fishery for Patagonian toothfish where interactions with albatrosses occur, night setting has resulted in considerable bycatch reductions. Night setting has also been proven to be efficient in pelagic fisheries, but this measure should be used in combination with streamer lines and weighted longlines in areas inhabited by nocturnal and diving birds. The main cause of mortality in trawl fisheries is collision with warp and netsonde cables, but studies are fragmentary. Interactions between cables and seabirds have been shown to be rare at times of no offal discharge, suggesting that a no-discharge policy would virtually eliminate mortality. Streamer lines have been proven to effectively reduce cable strikes under offal discharge. Measures to prevent birds from diving into the trawl net meshes have not been tested. Efficient mitigation methods that maintain target fish catch still have to be identified for gillnet fisheries. Future research in longline fisheries should fine-tune the most promising measures for each specific fishery. Effective measures identified for trawl fisheries need to be expanded to and tested in other areas where seabird interactions occur.

• Wakefield, E.D., Phillips, R.A., Trathan, P.N., Arata, J., Gales, R., Huin, N., Robertson, G., Waugh, S.M., Weimerskirch, H., and Matthiopoulos, J.  Habitat preference, accessibility, and competition limit the global distribution of breeding Black-browed Albatrosses.  Ecological Monographs 81(1): 141-167, 2011. 
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  Telemetry methods and remote sensing now make it possible to record the spatial usage of wide-ranging marine animals and the biophysical characteristics of their pelagic habitats. Furthermore, recent statistical advances mean that such data can be used to test ecological hypotheses and estimate species' distributions. Black-browed Albatrosses Thalassarche melanophrys are highly mobile marine predators with a circumpolar breeding and foraging distribution in the Southern Hemisphere. Although they remain relatively abundant, increased fisheries bycatch has led to their listing as endangered by conservation bodies. We satellite-tracked 163 breeding Black-browed Albatrosses and eight closely related Campbell Albatrosses T. impavida from nine colonies. We then quantified habitat usage, and modeled population-level spatial distribution at spatiotemporal scales >50 km and 1 month, as a function of habitat accessibility, habitat preference, and intraspecific competition, using mixed-effects generalized additive models (GAMM). During incubation, birds foraged over a wider area than in the post-brood chick-rearing period, when they are more time constrained. Throughout breeding, the order of habitat preference of Black-browed Albatrosses was for neritic (0-500 m), shelf-break and upper shelf-slope (500-1000 m), and then oceanic (>1000 m) waters. Black-browed Albatrosses also preferred areas with steeper (>3 degrees) bathymetric relief and, in addition, during incubation, warmer sea surface temperatures (peak preference ~16 ºC). Although this suggests specialization in neritic habitats, incubation-stage Black-browed Albatrosses from South Georgia also foraged extensively in oceanic waters, preferring areas with high eddy kinetic energy (>250 cm²/s²), especially the Brazil-Malvinas Confluence, a region of intense mesoscale turbulence. During chick-rearing, this species had a more southerly distribution, and following the seasonal retreat of sea ice, birds from some populations utilized neritic polar waters. Campbell Albatrosses showed similar bathymetric preferences but also preferred positive sea level anomalies. Black-browed Albatross foraging areas were partially spatially segregated with respect to colony and region, with birds preferring locations distant from neighboring colonies, presumably in order to reduce competition between parapatric conspecifics. At the global scale, the greatest concentrations of breeding Black-browed Albatrosses are in southern South American neritic, shelf-break, and shelf-slope waters. These regions also hold large fisheries and should therefore be a priority for introduction of bycatch mitigation measures.

• Doughty, R.W.  Saving the albatross: Fashioning an environmental regime.  Geographical Review 100(2): 216-228, 2010. 
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  After enduring decades of exploitation, associated with marine-mammal persecution during the nineteenth century in the Southern Hemisphere, many albatross populations recovered. Albatross hunting ended by the mid 1900s as nations set aside breeding islands as parks and preserves. However, researchers began to note declines in the 1960s and traced them to deaths at sea due to industrial fishing. In this article I note the historic use of albatrosses and tracks efforts to establish international accords among states that will guide efforts to save what has become one of the most threatened bird groups in the world.

• Dillingham, P.W. and Fletcher, D.  Potential biological removal of albatrosses and petrels with minimal demographic information.  Biological Conservation 144(6): 1885-1894, 2011. 
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  Seabirds such as albatrosses and petrels are frequently caught in longline and trawl fisheries, but limited demographic data for many species creates management challenges. A method for estimating the potential biological removal (the PBR method) for birds requires knowledge of adult survival, age at first breeding, a conservation goal, and the lower limit of a 60% confidence interval for the population size. For seabirds, usually only the number of breeding pairs is known, rather than the actual population size. This requires estimating the population size from the number of breeding pairs when important demographic variables, such as breeding success, juvenile survival, and the proportion of the adult population that engages in breeding, are unknown. In order to do this, a simple population model was built where some demographic parameters were known while others were constrained by considering plausible asymptotic estimates of the growth rate. While the median posterior population estimates are sensitive to the assumed population growth rate, the 20th percentile estimates are not. This allows the calculation of a modified PBR value that is based on the number of breeding pairs instead of the population size. For threatened albatross species, this suggests that human-caused mortalities should not exceed 1.5% of the number of breeding pairs, while for threatened petrel species, mortalities should be kept below 1.2% of the number of breeding pairs. The method is applied to 22 species and sub-species of albatrosses and petrels in New Zealand that are of management concern, of which at least 10 have suffered mortalities near or above these levels.

• Rains, D., Weimerskirch, H., and Burg, T.M.  Piecing together the global population puzzle of wandering albatrosses: genetic analysis of the Amsterdam albatross Diomedea amsterdamensis.  Journal of Avian Biology 42(1): 69-79, 2011.
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  Wandering albatrosses have been subjected to numerous taxonomic revisions due to discoveries of new species, analyses of morphological data and, more recently, the inclusion of genetic data. The small population of albatrosses (170 individuals including 26 pairs breeding annually) on Amsterdam Island in the Indian Ocean, Diomedea amsterdamensis, has been given species status based on plumage and morphometrics, but genetic data published to date provide weak support and its specific status remains controversial for some authors. We used mitochondrial control region sequence data to elucidate the relationship of the Amsterdam albatross within the wandering albatross complex (Diomedea amsterdamensis, D. antipodensis, D. dabbenena and D. exulans). Three novel haplotypes were present in 35 individuals from Amsterdam Island, and were highly divergent (3.6-7.3%) from haplotypes found in the other three members of the wandering albatross complex. Low levels of genetic variation in Amsterdam albatross likely resulted, at least in part, from a population bottleneck. Geographic isolation in the wandering albatross complex is maintained by high natal philopatry. As Amsterdam Island is the only breeding ground for this critically endangered species, we strongly urge conservation efforts in the area, especially in relation to long line fisheries and other threats such as disease and introduced predators, and it be listed as a distinct species.

• Vo, A.-T.E., Bank, M.S., Shine, J.P., and Edwards, S.V.  Temporal increase in organic mercury in an endangered pelagic seabird assessed by century-old museum specimens.  Proceedings of the National Academy of Sciences 108(18): 7466-7471, 2011.
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  Methylmercury cycling in the Pacific Ocean has garnered significant attention in recent years, especially with regard to rising mercury emissions from Asia. Uncertainty exists concerning whether increases in anthropogenic emissions over time may have caused increased mercury bioaccumulation in the biota. To address this, we measured total mercury and, for a subset of samples, methylmercury (the bioaccumulated form of mercury) in museum feathers from an endangered seabird, the black-footed albatross (Phoebastria nigripes), spanning a 120-y period. We analyzed stable isotopes of nitrogen (δ¹⁵N) and carbon (δ¹³C) to control for temporal changes in trophic structure and diet. In post-1940 and -1990 feathers, we detected significantly higher mean methylmercury concentrations and higher proportions of samples exhibiting above deleterious threshold levels (~40,000 ng·g-1) of methylmercury relative to prior time points, suggesting that mercury toxicity may undermine reproductive effort in the species. We also found higher levels of (presumably curator-mediated) inorganic mercury in older specimens of albatross as well as two nonpelagic species lacking historical exposure to bioavailable mercury, patterns suggesting that studies on bioaccumulation should measure methylmercury rather than total mercury when using museum collections. δ¹⁵N contributed substantially to models explaining the observed methylmercury variation. After simultaneously controlling for significant trends in δ¹³C over time and δ¹⁵N with methylmercury exposure, year remained a significant independent covariate with feather methylmercury levels among the albatrosses. These data show that remote seabird colonies in the Pacific basin exhibit temporal changes in methylmercury levels consistent with historical global and recent regional increases in anthropogenic emissions.

• Rayner, M.J., Carraher, C.J.F., Clout, M.N., and Hauber, M.E.  Mitochondrial DNA analysis reveals genetic structure in two New Zealand Cook's petrel (Pterodroma cookii) populations.  Conservation Genetics 11(5): 2073-2077, 2010. 
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  The endangered Cook's petrel (Pterodroma cookii) is restricted to two separated populations at the extremes of its former range across New Zealand. Prior work revealed morphological, foraging, and reproductive isolation between these two remnant populations. To aid the conservation management of the species, additional information is required on the genetic structure of Cook's petrel. We used mitochondrial DNA sequences (Cytochrome Oxidase subunit 1 gene), collected from 26 and 19 Cook's petrel breeding on Little Barrier Island (LBI) and Codfish Island (CDF), respectively, for this preliminary study. We uncovered distinct population genetic structure with analysis of molecular variance suggesting genetic isolation of the populations. Levels of genetic variation were higher in the LBI population (four haplotypes present; h = 0.34 and p = 0.10) whereas the CDF population had only one haplotype that was distinct from the LBI population. Our results indicate that Cook's petrel constitute two distinct management units for which conservation of genetic as well as behavioural and morphological diversity should be a priority. Further genetic studies using nuclear markers are recommended.

• Ryan, P.G. and Ronconi, R.A.  Continued increase in numbers of spectacled petrels Procellaria conspicillata.  Antarctic Science 23(4): 332-336, 2011. 
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  Until recently, the spectacled petrel  Procellaria conspicillata Gould was listed as Critically Endangered due to its small population size and ongoing incidental mortality on fishing gear. Surveys at its sole breeding locality, Inaccessible Island in the central South Atlantic Ocean, indicated that the population increased from 1999–2004, resulting in the species being down-listed to Vulnerable. We repeated the census of breeding spectacled petrels during the early incubation period in October–November 2009. Numbers of burrows increased by 55% from 2004–09, with increases in all count zones, and the greatest changes in peripheral populations. Burrow occupancy estimates remained high, averaging 81% during one-off checks. Our best estimate of the population in 2009 was 14 400 pairs, continuing the c. 7% per year increase inferred since the 1930s following the disappearance of introduced pigs. This confirms the rapid recovery of this species despite ongoing mortality on fishing gear. Our results suggest that at least some procellariiforms are able to sustain strong growth rates in the face of fishing mortality when colony based threats are removed.

• Welch, A.J., Yoshida, A.A., and Fleischer, R.C.  Mitochondrial and nuclear DNA sequences reveal recent divergence in morphologically indistinguishable petrels.  Molecular Ecology 20(7): 1364-1377, 2011. 
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  Often during the process of divergence, genetic markers will only gradually obtain the signal of isolation. Studies of recently diverged taxa utilizing both mitochondrial and nuclear data sets may therefore yield gene trees with differing levels of phylogenetic signal as a result of differences in coalescence times. However, several factors can lead to this same pattern, and it is important to distinguish between them to gain a better understanding of the process of divergence and the factors driving it. Here, we employ three nuclear intron loci in addition to the mitochondrial Cytochrome b gene to investigate the magnitude and timing of divergence between two endangered and nearly indistinguishable petrel taxa: the Galapagos (GAPE) and Hawaiian (HAPE) petrels (Pterodroma phaeopygia and P. sandwichensis). Phylogenetic analyses indicated reciprocal monophyly between these two taxa for the mitochondrial data set, but trees derived from the nuclear introns were unresolved. Coalescent analyses revealed effectively no migration between GAPE and HAPE over the last 100 000 generations and that they diverged relatively recently, approximately 550 000 years ago, coincident with a time of intense ecological change in both the Galapagos and Hawaiian archipelagoes. This indicates that recent divergence and incomplete lineage sorting are causing the difference in the strength of the phylogenetic signal of each data set, instead of insufficient variability or ongoing male-biased dispersal. Further coalescent analyses show that gene flow is low even between islands within each archipelago suggesting that divergence may be continuing at a local scale. Accurately identifying recently isolated taxa is becoming increasingly important as many clearly recognizable species are already threatened by extinction.

• Carey, M.J.  Investigator disturbance reduces reproductive success in Short-tailed Shearwaters Puffinus tenuirostris.  Ibis 153(2): 363-372, 2011. 
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  Research procedures can have a detrimental effect on the reproductive success of the study species. In this study, the frequency of investigator disturbance on Short-tailed Shearwaters Puffinus tenuirostris was examined experimentally throughout the incubation period to assess whether disturbance influences hatching success, pre-fledging chick survival and chick body size. Handling of incubating birds every day, every 3 days and once a week reduced hatching success by 100, 61 and 39%, respectively, compared with pairs that were not disturbed. Most failures resulted from egg abandonment by the parents, particularly during the early stage of incubation. Chick survival did not differ between treatment groups, but control chicks were significantly heavier and had larger bill depths and longer wings. The difference in chick body mass and size observed between the control and disturbed chicks might be due to physiological or behavioural mechanisms in adults or carry-over effects from the incubation stage to the next life-history stage. Reduced offspring quality has the potential to affect post-fledging survival and recruitment. These findings are significant in broader terms because any investigator disturbance that reduces reproductive success, survival and offspring fitness could interfere with the accurate assessment of demographic parameters and exacerbate population declines.

• Oppel, S., Raine, A.F., Borg, J.J., Raine, H., Bonnaud, E., Bourgeois, K., and Breton, A.R.  Is the Yelkouan shearwater Puffinus yelkouan threatened by low adult survival probabilities?  Biological Conservation 144(9): 2255-2263, 2011. 
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  Many seabird species are experiencing population declines, with key factors being high adult mortality caused by fishery by-catch and predation by introduced predators on nesting islands. In the Mediterranean, both of these pressures are intensive and widespread. We studied the adult survival of an endemic Mediterranean seabird, the Yelkouan shearwater (Puffinus yelkouan), between 1969-1994 and 2007-2010 in Malta and between 2004-2010 in France using mark-recapture methods. Mean annual survival probabilities for breeding adults were below 0.9 for all colonies and periods. Between 1969-1994, annual survival for adults of unknown breeding status was on average 0.74 (95% confidence interval: 0.69-0.80) in Malta, possibly as a result of various human disturbances (including illegal shooting), light pollution and fisheries by-catch. Over the period 2004-2010, we found strong support for variation in adult survival probabilities between breeders and non-breeders, and islands with and without introduced predators in France. Survival probabilities for non-breeders (0.95, 0.81-1.0) appeared to be higher than for breeders (0.82, 0.70-0.94), but were imprecise partly due to low recapture probabilities. In Malta, we found evidence for heterogeneity in survival probabilities between two unknown groups (probably breeders and non-breeders), and seasonal variation in survival probability. Birds were more likely to survive the period including the peak breeding season than an equally long period during which they roam widely at sea. Although annual adult survival probability was still low (0.85, 0.58-1.0), colony protection measures appear to have reduced mortality at nesting cliffs. A population model indicated that colonies in France and Malta would currently require continuous immigration of 5-12 pairs per year to maintain stable populations. Our estimates of adult survival probabilities over the past four decades are consistent with overall population declines. Threats to Yelkouan shearwaters require immediate management actions to avoid ongoing population declines in the western Mediterranean.

• Clucas, R.  Long-term population trends of Sooty Shearwater (Puffinus griseus) revealed by hunt success.  Ecological Applications 21(4): 1308-1326, 2011. 
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  The annual hunt of Muttonbirds (chicks of the Sooty Shearwater, Puffinus griseus), undertaken by the Rakiura Māori people of southern New Zealand, is economically and socially integral to their cultural identity. Muttonbirders concerned at ensuring that the hunt remains viable for coming generations have provided catch records to help ascertain historic trends in hunt success. Analysis of eight catch diaries for a 67-year period demonstrates considerable consistency across diaries in the variability of hunt success, as measured by annualized mean daily hunt tallies. A conservative estimate of the overall annual decline in hunt success is -1.89% (95% CI: -1.14% to -2.65%). Birders' observations of a changing relationship between chick quality and hunt success was evidenced across diaries. Reduced hunt success from the 1990s indicates that possible adult "knockdowns" and/or sustained substantial reductions in breeding proportions have occurred. Chick size has remained constant, suggesting little change in the provisioning environment. Catch per unit effort data, provided by a single diary, confirms a link between variability in annual hunt success and chick abundance. The Pacific Decadal Oscillation (PDO) and the Southern Annular Mode (SAM) are correlated with hunt success and chick size, respectively. Interannual PDO⁺ (or PDO^-) values are correlated with higher (or lower) tallies, whereas SAM⁺ (or SAM^-) values are associated with larger (or smaller) chick size. Uncertainty in the relationship between the breeding Sooty Shearwater population, chick catch, and environmental perturbation in their feeding grounds could be reduced with the inclusion of hunt time in all diary records. Ongoing prolonged decline in a top-trophic-level predator such as the Sooty Shearwater raises serious concern that long-term oceanic changes have been occurring and that long-term sustainability of muttonbirding is in doubt.

• Riou, S., Gray, C.M., Brooke, M.D., Quillfeldt, P., Masello, J.F., Perrins, C., and Hamer, K.C.  Recent impacts of anthropogenic climate change on a higher marine predator in western Britain.  Marine Ecology Progress Series 422: 105-112, 2011. 
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  Impacts of anthropogenic climate change on marine ecosystems are now widely acknowledged. In the NE Atlantic, abundant evidence from the partly enclosed waters of the North Sea indicates that recent climate-induced changes in primary and secondary productivity have been propagated up the food chain, with marked consequences for higher vertebrate predators such as seabirds. In contrast, however, there is much less indication of such impacts on higher predators in the more open Atlantic waters around the west coast of the British Isles. Through an annual comparison of chick growth and adult food provisioning behaviour of Manx shearwaters in SW Wales, we found that birds bred later and chicks attained lower peak and fledging masses in 2007 and 2008 than in any previous recorded year dating back to 1965. These changes were accompanied by a reduction in parental attendance at the colony, which was probably the result of parents switching to a dual foraging strategy in 2007 and 2008. These events were linked to higher sea surface temperature in the preceding winter and to a reduction in prey quality, as indicated by the mean body mass of 2 yr old herring. These are the first such findings for the west coast of Britain and indicate that within the NE Atlantic region, adverse impacts of climate change on higher marine predators are no longer restricted to the vicinity of the North Sea.

• Velando, A. and Munilla, I.  Disturbance to a foraging seabird by sea-based tourism: Implications for reserve management in marine protected areas.  Biological Conservation 144(3): 1167-1174, 2011. 
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  The provision of recreational opportunities is one of the important human goals of marine protected areas. However, as levels of recreational use increase, human disturbance is likely to cause significant detrimental effects upon wildlife. Here we evaluate the best managing options to mitigate the impact of sea-based tourism on the foraging activity of an endangered population of European shags, Phalacrocorax aristotelis, in a coastal marine protected area (Cies islands, north-western Iberia). Boat disturbance elicited a characteristic avoidance behavior that resulted in a substantial reduction in foraging activity as levels of boat use increased. Moreover, boats excluded shags from the best feeding areas, resulting in higher densities of foragers in areas of little boat traffic. We used a behavioral model to explore the effects of managing strategies aimed at reducing the impact of boats on the foraging activity of shags. Our model suggested that in low boat disturbance scenarios limiting the number of boats using the reserve would be a better management option than habitat protection (i.e. the establishment of set-aside areas free of boat traffic). On the contrary, when boat disturbance levels are high the protection of habitat is recommendable, even if spatial variation in habitat quality is unknown or poorly assessed. Our study stresses the point that management strategies to minimize disturbance to foraging seabirds may depend on the spatial overlap between sea-based recreational activities and foraging seabirds and the spatial variation in marine habitat quality for seabirds.

• Karnovsky, N., Harding, A., Walkusz, W., Kwasniewski, S., Goszczko, I., Wiktor, J., Routti, H., Bailey, A., McFadden, L., Brown, Z., Beaugrand, G., and Grémillet, D.  Foraging distributions of little auks Alle alle across the Greenland Sea: implications of present and future Arctic climate change.  Marine Ecology Progress Series 415: 283-293, 2010. 
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  The Arctic is undergoing widespread warming. In order to understand the impact of climate change on Arctic marine food webs, we studied the at-sea distribution of foraging little auks in contrasting conditions of the Greenland Sea. While the eastern side of the Greenland Sea has experienced recent warming, the western side is still dominated by cold, Arctic water in the East Greenland Current. We hypothesized that foraging little auks would be found in greatest abundance in cold Arctic waters bearing more lipid-rich prey, allowing them to deliver more energy-rich food to their chicks. To test our hypotheses, we made ship-borne bird observations and zooplankton tows, as well as analyses of chick meals at 2 little auk colonies adjacent to 3 distinct water masses in the Greenland Sea. Associated with the coldest water in the East Greenland Current, we found the highest concentrations of large Calanus copepods (C. glacialis and C. hyperboreus), as well as the highest concentrations of foraging little auks, indicating a relationship that is likely to be disrupted by increasing water temperatures. To assess potential future impacts of ocean warming, we used a coupled atmosphere-ocean global climate model (AOGCM) to predict Greenland Sea sea-surface temperatures over the study area at the end of the 21st century. Our results suggest that 4 of 8 little auk breeding colonies in the North Atlantic may be negatively impacted as temperatures exceed the thermal preferenda of large Calanus, which is the preferred prey of little auks during the breeding season.

• Garcia-Borboroglu, P. et al.  Magellanic penguin mortality in 2008 along the SW Atlantic coast.  Marine Pollution Bulletin 60(10): 1652-1657, 2010. 
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  Magellanic penguins migrate from Patagonia reaching northern Argentina, Uruguay, and southern Brazil on their winter migration, in parallel with the seasonal pulse of anchovy spawning. In 2008, Magellanic penguins went further north than usual. Many died and a few swam nearly to the Equator. Twelve groups surveyed 5000 km of coastline encountering 3371 penguins along the coast. Most penguins arrived in northern Brazil (68.4%) without petroleum (2933, 87%). Almost all penguins without petroleum were juveniles (2915, 99%) and 55% were alive when found. Penguins were dehydrated, anemic, hypothermic, and emaciated. Of the penguins with petroleum, 13% arrived in the southern half of Brazil, showing that petroleum pollution remains a problem along the SW Atlantic coast. The mortality occurred in the winter of 2008 when sea surface temperature were unusually cold perhaps reducing the prey for penguins.

• Trathan, P.N., Fretwell, P.T., and Stonehouse, B.  First recorded loss of an emperor penguin colony in the recent period of Antarctic regional warming: Implications for other colonies.  PLoS ONE 6(2): art. e14738, 2011.
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  In 1948, a small colony of emperor penguins Aptenodytes forsteri was discovered breeding on Emperor Island (67° 51' 52" S, 68° 42' 20" W), in the Dion Islands, close to the West Antarctic Peninsula (Stonehouse 1952). When discovered, the colony comprised approximately 150 breeding pairs; these numbers were maintained until 1970, after which time the colony showed a continuous decline. By 1999 there were fewer than 20 pairs, and in 2009 high-resolution aerial photography revealed no remaining trace of the colony. Here we relate the decline and loss of the Emperor Island colony to a well-documented rise in local mean annual air temperature and coincident decline in seasonal sea ice duration. The loss of this colony provides empirical support for recent studies (Barbraud & Weimerskirch 2001; Jenouvrier et al 2005, 2009; Ainley et al 2010; Barber-Meyer et al 2005) that have highlighted the vulnerability of emperor penguins to changes in sea ice duration and distribution. These studies suggest that continued climate change is likely to impact upon future breeding success and colony viability for this species. Furthermore, a recent circumpolar study by Fretwell & Trathan (2009) highlighted those Antarctic coastal regions where colonies appear most vulnerable to such changes. Here we examine which other colonies might be at risk, discussing various ecological factors, some previously unexplored, that may also contribute to future declines. The implications of this are important for future modelling work and for understanding which colonies actually are most vulnerable.

• Trivelpiece, W.Z., Hinke, J.T., Miller, A.K., Reiss, C.S., Trivelpiece, S.G., and Watters, G.M.  Variability in krill biomass links harvesting and climate warming to penguin population changes in Antarctica.  Proceedings of the National Academy of Sciences 108(18): 7625-7628, 2011.
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  The West Antarctic Peninsula (WAP) and adjacent Scotia Sea support abundant wildlife populations, many of which were nearly extirpated by humans. This region is also among the fastest-warming areas on the planet, with 5-6 °C increases in mean winter air temperatures and associated decreases in winter sea-ice cover. These biological and physical perturbations have affected the ecosystem profoundly. One hypothesis guiding ecological interpretations of changes in top predator populations in this region, the "sea-ice hypothesis," proposes that reductions in winter sea ice have led directly to declines in "ice-loving" species by decreasing their winter habitat, while populations of "ice-avoiding" species have increased. However, 30 y of field studies and recent surveys of penguins throughout the WAP and Scotia Sea demonstrate this mechanism is not controlling penguin populations; populations of both ice-loving Adélie and ice-avoiding chinstrap penguins have declined significantly. We argue in favor of an alternative, more robust hypothesis that attributes both increases and decreases in penguin populations to changes in the abundance of their main prey, Antarctic krill. Unlike many other predators in this region, Adélie and chinstrap penguins were never directly harvested by man; thus, their population trajectories track the impacts of biological and environmental changes in this ecosystem. Linking trends in penguin abundance with trends in krill biomass explains why populations of Adélie and chinstrap penguins increased after competitors (fur seals, baleen whales, and some fishes) were nearly extirpated in the 19th to mid-20th centuries and currently are decreasing in response to climate change.

• Cardoso, L.G., Bugoni, L., Mancini, P.L., and Haimovici, M.  Gillnet fisheries as a major mortality factor of Magellanic penguins in wintering areas.  Marine Pollution Bulletin 62(4): 840-844, 2011. 
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  The incidental capture in fisheries is probably the main conservation problem affecting seabirds. While the capture of albatrosses and petrels on longline hooks is well-known worldwide, the bycatch of diving seabirds in gillnets is an overlooked conservation problem. During a winter coastal fishing trip, the capture of Magellanic penguins (Spheniscus magellanicus) was recorded in driftnet and bottom setnet fisheries for the first time in southern Brazil. The highest captures rates were found in driftnets, from 146.5 to 545.5 penguins/km² of net and a total of 56 dead penguins were recorded. In the bottom gillnet, a total of 12 birds were killed and the capture rates varied from 41.7 to 125.0 penguins/km² of net. Although preliminary, the results presented in this paper were consistent between sets. If we consider the magnitude of driftnet and setnet fishing fleets, and that most dead penguins were adults, the impact upon Magellanic penguin populations is probably significant.

• Deem, S.L., Merkel, J., Ballweber, L., Vargas, F.H., Cruz, M.B., and Parker, P.G.  Exposure to Toxoplasma gondii in Galapagos penguins (Spheniscus mendiculus) and flightless cormorants (Phalacrocorax harrisi) in the Galapagos Islands, Ecuador.  Journal of Wildlife Diseases 46(3): 1005-1011, 2010. 
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  Toxoplasma gondii is one of the most common protozoan parasites of humans and warm-blooded animals. Members of the family Felidae are the only definitive hosts of this parasite and, thus, important in the epidemiology of the disease. Previous studies on Pacific islands have found T. gondii infections in a number of avian species where domestic cats (Felis catus) have been introduced. Little is known about T. gondii in the Galapagos Islands, although introduced domestic cats in the archipelago are known to be T. gondii antibody-positive. In this study, we quantified prevalence of antibody to T. gondii in two threatened avian marine species, Galapagos penguins (Spheniscus mendiculus) and flightless cormorants (Phalacrocorax harrisi), and tested the hypothesis that this parasite is more prevalent on Isabela Island (with cats) than on Fernandina Island (without cats). Overall, antibody prevalence was 2.3% in both Galapagos penguins and flightless cormorants from samples collected during 2003-2005, and in 2008. In Galapagos penguins (n = 298), a significantly higher antibody prevalence was found in penguins on Fernandina Island (free of cats) than on Isabela Island (with cats, Fisher's exact test, P = 0.02). In flightless cormorants (n = 258), there was a higher antibody prevalence in cormorants living on Isabela than on Fernandina, although this difference was not statistically significant (Fisher's, P = 0.19). This study is the first to show exposure to T. gondii in endemic avian species in the Galapagos Islands, providing evidence for disease-related risks associated with the feral cat population in the archipelago. We provide possible explanations for these findings and recommendations for future studies towards a better understanding of the epidemiology of T. gondii in the Galapagos Islands.

• Ludynia, K., Roux, J.P., Jones, R., Kemper, J., and Underhill, L.G.  Surviving off junk: low-energy prey dominates the diet of African penguins Spheniscus demersus at Mercury Island, Namibia, between 1996 and 2009.  African Journal of Marine Science 32(3): 563-572, 2010. 
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  The diet of African penguins Spheniscus demersus in Namibia consisted mainly of sardine Sardinops sagax in the 1950s. Since the collapse of pelagic fish stocks in the 1970s, birds fed mainly on bearded (pelagic) goby Sufflogobius bibarbatus, a low-energy prey species. We present diet data for African penguins breeding at Mercury Island, the largest colony for this species in Namibia, between 1996 and 2009. Bearded goby was the main prey item throughout the study period, both in terms of frequency of occurrence (67.8%; SD 31.2) and in terms of mass (59.2%; SD 31.5). Diet composition varied throughout the year as well as between years; birds occasionally fed on a variety of fish species other than bearded goby. In Namibia, poor prey abundance is considered as a major factor contributing to the decline of penguin numbers after the collapse of the sardine stocks. However, bearded goby appears to be relatively abundant along Namibia's southern coast and low prey quality rather than low abundance appears to be a key factor influencing population dynamics of African penguins and other marine top predators in southern Namibia.

• Wienecke, B.  Review of historical population information of emperor penguins.  Polar Biology 34(2): 153-167, 2011. 
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  In 1902, the first breeding colony of emperor penguins was discovered. Over the following decades, the number of known emperor penguin colonies increased steadily and new ones are still being discovered. However, rigorous census work has been carried out at only a few colonies and accurate information on trends in breeding populations is limited to a small number of locations. Thus, the total number of breeding pairs is still unknown as is the size of the global population (breeders, non-breeders, juveniles). The International Union for the Conservation of Nature (IUCN) lists the species' status as 'least concern' and states that although the population trend for emperor penguins has not been quantified, the global population appears to be stable. This review summarises the currently available information on the populations of emperor penguins at known colonies in terms of survey methods, count units used and survey frequency. It examines what is known about the state of various colonies and demonstrates that currently available data are inadequate for a trend assessment of the global population.

• Zabala, J., Zuberogoitia, I., Martinez-Climent, J.A., and Etxezarreta, J.  Do long lived seabirds reduce the negative effects of acute pollution on adult survival by skipping breeding? A study with European storm petrels (Hydrobates pelagicus) during the ''Prestige'' oil-spill.  Marine Pollution Bulletin 62(1): 109-115, 2011.
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  We estimated the survival probability of breeding European storm petrels before, during and after a severe oil-spill. We hypothesized that petrels might have deserted the breeding colony to maximize their own survival probability and we expected no major change on adult survival probabilities as a consequence of the spill. We used an information-theoretical approach and multi-model inference to assess the strength of the evidence in favour of different hypotheses. Evidence contained in the data clearly supported the non-effect of the spill on adult survival hypothesis while punctual impact of the spill on survival and expanded (3 years) impact alternatives received less support. The effect size of the spill on averaged survival estimates was negligible in every case. We suggest that petrels minimized the impact of acute pollution by not investing in reproduction. We suggest that short-medium term management actions after oil-spills and similar catastrophes should focus on ecosystem restoration.

• Votier, S.C., Archibald, K., Morgan, G., and Morgan, L.  The use of plastic debris as nesting material by a colonial seabird and associated entanglement mortality.  Marine Pollution Bulletin 62(1): 168-172, 2011.
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  Entanglement with plastic debris is a major cause of mortality in marine taxa, but the population-level consequences are unknown. Some seabirds collect marine debris for nesting material, which may lead to entanglement. Here we investigate the use of plastics as nesting material by northern gannets Morus bassanus and assess the associated levels of mortality. On average gannet nests contained 469.91 g (range 0 - 1293 g) of plastic, equating to an estimated colony total of 18.46 tonnes (range 4.47 - 42.34 tonnes). The majority of nesting material was synthetic rope, which appears to be used preferentially. On average 62.85 ± 26.84 (range minima 33 - 109) birds were entangled each year, totalling 525 individuals over eight years, the majority of which were nestlings. Although mortality rates are high, they are unlikely to have population-level effects. The use of synthetic fibres as nesting material is a common strategy among seabirds, but the impacts of entanglement warrants further investigation.

• Koivula, M.J. and Eeva, T.  Metal-related oxidative stress in birds.  Environmental Pollution 158(7): 2359-2370, 2010. 
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  Metals can cause oxidative stress by increasing the formation of reactive oxygen species (ROS), which render antioxidants incapable of defence against growing amounts of free radicals. Metal toxicity is related to their oxidative state and reactivity with other compounds. Our aim is to review the mechanisms on how metals cause oxidative stress and what is known about metal-induced oxidative stress in wildlife. Taking birds as model organisms, we summarize the mechanisms responsible for antioxidant depletion and give a view of how to detect metal-induced oxidative stress in birds by using different biomarkers. The mechanisms producing the harmful effects of oxidative stress are complex with different biomolecular mechanisms associated with ecotoxicological and ecological aspects. The majority of the studies concerning metals and ROS related to oxidative stress have focused on the biomolecular level, but little is known about the effects at the cellular level or at the level of individuals or populations.

• Regular, P.M., Robertson, G.J., Montevecchi, W.A., Shuhood, F., Power, T., Ballam, D., and Piatt, J.F.  Relative importance of human activities and climate driving common murre population trends in the Northwest Atlantic.  Polar Biology 33(9): 1215-1226, 2010. 
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  Seabird populations are affected by environmental and anthropogenic influences on a global scale. Many population-level responses to climate change have been shown, yet few studies have addressed the additive and/or relative impact of environmental and anthropogenic influences on seabird populations. Using a mixed model approach, we analyzed the trends in plot counts of common murres (Uria aalge) from a Low Arctic colony at Cape St. Mary's, Newfoundland, across 26 years (1980-2006). We tested for associations between population change and various environmental and anthropogenic covariates: water temperature, winter North Atlantic Oscillation, hunting mortality, oil pollution, by-catch in fishing gear, and visitor disturbance. The number of murres occupying central plots decreased from 1980 to 1989 and increased from 1990 to 2006. Annual changes in the population were negatively associated with the estimated number of murres killed in the Newfoundland murre hunt and the high numbers killed in the early 1980s likely caused the observed population decline. The large number of gillnets set in Newfoundland waters during the 1980s, and associated incidence of drowning through by-catch, probably also contributed to the observed decline. Though a centennially significant cold-water perturbation in 1991 forced a regime shift in pelagic food webs, the effect of ocean climate variability on the population was not obvious. We conclude that management efforts should focus on assessing and mitigating the effects of human-induced influences and consider the potential additive effects of climate change.

• Joiris, C.R. and Falck, E.  Summer at-sea distribution of little auks Alle alle and harp seals Pagophilus (Phoca) groenlandica in the Fram Strait and the Greenland Sea: impact of small-scale hydrological events.  Polar Biology 34(4): 541-548, 2011. 
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  Among the most numerous seabird and pinniped species of the Fram Strait and the Greenland Sea, little auks Alle alle and harp seals Pagophila (Phoca) groenlandica are very abundant in the mixed Polar/Arctic Waters at the front between the two water masses. This must reflect the presence of very high concentrations of their food, Arctic zooplankton and nekton, massively attracting their predators. Such a high biological production seems to be depending on new primary production based on upwelling and high nutrient concentration. This usually takes place at the ice edge (e.g. July 2005), but hydrological conditions such as eddies can modify its position, east of the front in open water as caused by a subsurface eddy (August 2005), or in ice-covered areas if westerly winds push the pack ice to the east, eventually covering an eddy and causing very high concentrations of little auks and harp seals (July 2008). On the other hand, a dramatic decrease of pack ice coverage can move this water mass farther north and west, making it inaccessible to little auks during their breeding season, and apparently causing breeding failure in Jan Mayen in July 2005. In future years, if a much stronger diminution in sea ice coverage will take place, similar to the retreat in 2005 and 2007, the failure might affect the whole Spitsbergen population, as well as other seabird species feeding mainly at the ice edge.

• Catry, P., Almeida, A., Lecoq, M., Granadeiro, J.P., and Matias, R.  Low breeding success and sharp population decline at the largest known Falkland skua colony.  Polar Biology 34(8): 1239-1241, 2011. 
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  The Falkland skua Stercorarius antarctica antarctica is a poorly known seabird. Demographic studies at the largest known colony of this taxon revealed a sharp population decline (47%) in just 5 years, between 2004 and 2009. The decline seems to be linked with a chronic low breeding success in the recent years and is consistent with a situation of virtually zero recruitment. The ultimate causes of the decline are, as of yet, unknown, but plausible explanations are examined and discussed. The reported population trends should be the cause of some concern, and more research and monitoring are desired.

• Hipfner, J.M., Lemon, M.J.F., and Rodway, M.S.  Introduced mammals, vegetation changes and seabird conservation on the Scott Islands, British Columbia, Canada.  Bird Conservation International 20(3): 295-305, 2010. 
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  The Scott Islands, British Columbia, Canada, support the largest aggregation of breeding seabirds in the eastern Pacific Ocean south of Alaska. However, large seabird populations were eradicated by American Mink Neovison vison and Raccoons Procyon lotor introduced to Lanz and Cox islands in the 1930s, while the ecological consequences of the introduction of European Rabbits Oryctolagus cuniculus to Triangle Island in the 1920s are unknown. We have seen dramatic changes in the vegetation on Triangle Island in recent decades, chiefly a decrease in Tufted Hairgrass Deschampsia cespitosa cover and a concomitant increase in Salmonberry Rubus spectabilis cover. We carried out vegetation surveys at Triangle Island (1989 and 2004) and its nearest neighbour, rabbit-free Sartine Island (1987 and 2006), to test the hypothesis that rabbits have caused these changes. We found, however, that similar changes have occurred at Sartine Island as at Triangle Island over the same time period. Because these two islands support the bulk of the world's breeding population of Cassin's Auklet Ptychoramphus aleuticus, a small seabird that selects grass-covered habitat but avoids tall Salmonberry for nesting, the vegetation changes raise serious concerns for a species that has experienced dramatic population declines in recent years. Restoration of seabird nesting habitat by removing American Mink and Raccoons from Lanz and Cox islands will be vital for long-term seabird conservation in the Scott Islands.

• Cruz-Delgado, F., Gonzalez, J.A., and Wiedenfeld, D.A.  Breeding biology of the Critically Endangered Galapagos Petrel Pterodroma phaeopygia on San Cristobal Island: conservation and management implications.  Bird Conservation International 20(3): 306-319, 2010.  
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  The Galapagos Petrel Pterodroma phaeopygia is endemic to the Galapagos Archipelago, where it nests on only five islands. The species is considered 'Critically Endangered', mostly due to the effects of alien invasive species, which impair its reproductive success. During 2002-2003 we studied the breeding biology of the petrels nesting on San Cristobal island. The study revealed particular characteristics of the San Cristobal petrel population and differences compared to those of other islands, mostly related to nesting habitat, phenology, reproductive success and causes of mortality. On San Cristobal, petrel nests were primarily located along ravines, in areas of dense vegetation cover formed by the endemic shrub Miconia robinsoniana and a wide variety of native ferns. Over 90% of the nests on the island were located on private agricultural land. The petrel population has a prolonged reproductive period covering 10 months. Laying dates occurred mostly from May to October, with a peak during August, although eggs may be occasionally laid between November and March. The incubation period averaged 50.8 days (range: 46-53), and parental care 103.7 days (range: 98-108). Overall reproductive success was 23.6%; 63.8% for eggs and 37.1% for chicks. Predation by rats was the primary cause (72.2%) of nest failure. Rat control campaigns and clearing of exotic plant species in areas of high density of petrel nests, as well as promoting cooperation agreements between conservation authorities and landowners of the properties where nests are located, are suggested among other critical management measures intended to reduce nest mortality and ensure the survival of the San Cristobal petrel population.

• Duffy, D.C.  Changing seabird management in Hawai'i: From exploitation through management to restoration.  Waterbirds 33(2): 193-207, 2010. 
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  Fossil evidence indicates that diverse and abundant seabird communities were once found in the main Hawaiian Islands. However, these seabird populations have severely decreased, or even disappeared, as a result of human disturbance, habitat loss and predation from introduced mammals. Today, the vast majority of Hawaii's seabirds nest on low-lying and uninhabited atolls in the Northwestern Hawaiian islands, some of which will not be able to withstand projected sea-level rises. As a result, populations of many seabird species will be further reduced unless suitable nesting habitat in the main Hawaiian Islands can be restored against predators. The history of seabird management in the Hawaiian Islands is examined, tracing three overlapping stages. The first emphasized exploitation the second recognized the damage done by humans and developed methods to remove the causes. The third and current stage focuses on restoration, initially of seabirds, and most recently of ecosystems. Restoration will require a scientific approach and documentation of successes and failures, improving the chances of success for future interventions.

• Jones, H.P.  Seabird islands take mere decades to recover following rat eradication.  Ecological Applications 20(8): 2075-2080, 2010. 
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  Islands house a majority of the world's biodiversity and are thus critical for biodiversity conservation. Seabird nesting colonies provide nutrients that are integral to maintain island biodiversity and ecosystem function. Invasive rats destroy seabird colonies and thus the island ecosystems that depend on seabird-derived nutrients. After rat eradication, it is unclear how long ecosystem recovery may take, although some speculate on the order of centuries. I looked at ecosystem recovery along a chronosequence of islands that had 12-22 years to recover following rat eradication. I show that soil, plant, and spider marine-derived nitrogen levels and C:N ratios take mere decades to recover even after centuries-long rat invasion. Moreover, active seabird restoration could speed recovery even further, giving much hope to quickly conserve many endemic species on islands worldwide.

• Tranquilla, L.M., Hedd, A., Burke, C., Montevecchi, W.A., Regular, P.M., Robertson, G.J., Stapleton, L.A., Wilhelm, S.I., Fifield, D.A., and Buren, A.D.  High Arctic sea ice conditions influence marine birds wintering in Low Arctic regions.  Estuarine, Coastal and Shelf Science 89(1): 97-106, 2010. 
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  Ocean climate change is having profound biological effects in polar regions. Such change can also have far-reaching downstream effects in sub-polar regions. This study documents an environmental relationship between High Arctic sea ice changes and mortality events of marine birds in Low Arctic coastal regions. During April 2007 and March 2009, hundreds of beached seabird carcasses and moribund seabirds were found along the east and northeast coasts of Newfoundland, Canada. These seabird ''wrecks'' (i.e. dead birds on beaches) coincided with a period of strong, persistent onshore winds and heavily-accumulated sea ice that blocked bays and trapped seabirds near beaches. Ninety-two percent of wreck seabirds were Thick-billed Murres (Uria lomvia). Body condition and demographic patterns of wreck murres were compared to Thick-billed Murres shot in the Newfoundland murre hunt. Average body and pectoral masses of wreck carcasses were 34% and 40% lighter (respectively) than shot murres, indicating that wreck birds had starved. The acute nature of each wreck suggested that starvation and associated hypothermia occurred within 2-3 days. In 2007, first-winter murres (77%) dominated the wreck. In 2009, there were more adults (78%), mostly females (66%). These results suggest that spatial and temporal segregation in ages and sexes can play a role in differential survival when stochastic weather conditions affect discrete areas where these groups aggregate. In wreck years, southward movement of Arctic sea ice to Low Arctic latitudes was later and blocked bays longer than in most other years. These inshore conditions corresponded with recent climate-driven changes in High Arctic ice break-up and ice extent; coupled with local weather conditions, these ice conditions appeared to be the key environmental features that precipitated the ice-associated seabird wrecks in the Low Arctic region.

• Harding, A.M.A., Welcker, J., Steen, H., Hamer, K.C., Kitaysky, A.S., Fort, J., Talbot, S.L., Cornick, L.A., Karnovsky, N.J., Gabrielsen, G.W., and Grémillet, D.  Adverse foraging conditions may impact body mass and survival of a high Arctic seabird.  Oecologia 167(1): 49-59, 2011.
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  Tradeoffs between current reproduction and future survival are widely recognized, but may only occur when food is limited: when foraging conditions are favorable, parents may be able to reproduce without compromising their own survival. We investigated these tradeoffs in the little auk (Alle alle), a small seabird with a single-egg clutch. During 2005-2007, we examined the relationship between body mass and survival of birds breeding under contrasting foraging conditions at two Arctic colonies. We used corticosterone levels of breeding adults as a physiological indicator of the foraging conditions they encountered during each reproductive season. We found that when foraging conditions were relatively poor (as reflected in elevated levels of corticosterone), parents ended the reproductive season with low body mass and suffered increased post-breeding mortality. A positive relationship between body mass and post-breeding survival was found in one study year; light birds incurred higher survival costs than heavy birds. The results of this study suggest that reproducing under poor foraging conditions may affect the post-breeding survival of long-lived little auks. They also have important demographic implications because even a small change in adult survival may have a large effect on populations of long-lived species.

• Peery, M.Z. and Henry, R.W.  Recovering marbled murrelets via corvid management: A population viability analysis approach.  Biological Conservation 143(11): 2414-2424, 2010. 
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  The expansion of human activities into rural areas and natural landscapes has resulted in widespread increases in the abundance of synanthropic species that threaten rarer native species. Quantitative assessments of how much impacts need to be reduced to reach acceptable levels of risk to the affected species are rarely conducted prior to the implementation of control measures, and it is perhaps not surprising that many efforts have not yielded the desired outcome. Here, we used matrix-based population viability analysis models to show that reducing predation by rapidly growing corvid populations on marbled murrelet (Brachyramphus marmoratus) nests likely constitutes an effective means for recovering a declining murrelet population in central California. For example, a modest 40% reduction in predation reduced extinction risk dramatically from 95.8% to 4.6% over 100 years and a 60% reduction resulted in a stable population (λ = 1) when the proportion of breeders, renesting rates, and corvid predation rates were assumed to be 0.77, 0.13, and 0.69, respectively. However, nest predation would only need to be reduced by 40% to produce a stable population if corvid management was coupled with a modest increase in after-hatch-year survival from 0.896 to 0.910. Corvid control resulted in greater gains in murrelet population size when the maximum number of breeders was allowed to increase over the projection period, as might be expected if the amount of old-growth nesting habitat increased over time, but extinction risk was insensitive to the presence of a carrying capacity. Approximately half of known murrelet nests in central California are within 1 km of heavily used campgrounds in a single state park, indicating that significant gains in viability could be achieved by targeting efforts in small areas providing corvid food subsidies. Risk assessments such as ours can provide quantitative prioritization rationale for efforts intended to mitigate the impacts of synanthropic species on threatened species.

• Hario, M. and Nuutinen, J.M.J.  Varying chick mortality in an organochlorine-''strained'' population of the nominate Lesser Black-backed Gull Larus f. fuscus in the Baltic Sea.  Ornis Fennica 88(1): 1-13, 2011.
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  Severe reproductive failure has contributed to a drastic population decline of the nominate Lesser Black-backed Gull ( Larus fuscus fuscus) in its breeding grounds in the Gulf of Finland and the Bay of Bothnia. In intensive field studies in the central area of the Gulf of Finland, roughly 65-70% of chicks died in their nest in the 1980s and 1990s due to innate diseases. In the 1990s, the fledging rate was only 0.02. The diseases consisted mainly of liver degeneration and various inflammations, and most chicks died of sepsis. The hepatic concentrations of legacy organochlorines (OC) in dead chicks were high, and they correlated with the proportion of dead chicks in a brood. During the 2000s, however, the occurrence of diseased chicks in the Gulf of Finland decreased to 48%, which helped to achieve a fledging rate supposedly sustaining the population (0.52). At the same time, the trends in hepatic levels of certain legacy OCs in chicks decreased, especially the DDE, HCB, β-HCH, and trans-nonachlor levels. In spite of skewed sampling (only dead chicks were available), our results indicate an enhancing health status among the present population, probably due to a less contaminated diet during the non-breeding period.

• Erikstad, K.E., Moum, T., Bustnes, J.O., and Reiertsen, T.K.  High levels of organochlorines may affect hatching sex ratio and hatchling body mass in arctic glaucous gulls.  Functional Ecology 25(1): 289-296, 2011.
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  1. Long range transportation via ocean currents and air of various organochlorines (OCs) has resulted in their intrusion in the high Arctic marine food web. At the Spitsbergen archipelago, including Bear Island (Norway), bioaccumulation in top predators like glaucous gulls (Larus hyperboreus) is high, severely affecting their breeding performance and survival. 2. In the present study, we examined the sex ratio of glaucous gull offspring at hatching in relation to the OC blood levels of female parents. Glaucous gulls have male-biased size dimorphism and females under stress with high levels of OCs are expected to skew the sex ratio towards the less costly female offspring. 3. Our data strongly suggest that among females with low levels of OCs, mothers in good body condition had a hatching sex ratio skewed towards males while those in poor body condition had a skew towards female offspring. However, contrary to expectations, females with high levels of OCs had a strong skew in sex ratio toward male offspring and this was most apparent among females in poor body condition. 4. Hatching body masses of male chicks (controlled for egg size) were negatively related to OC blood level of female parents. There was no such relationship for female offspring. 5. We discuss the skew in hatching sex ratio experienced by OC contaminated glaucous gulls in light of three hypotheses. One is that OC pollutants may mimic hormones and influence the sex determining processes suggested to be under control of steroids. Another is that female transfer of OCs to eggs may increase female embryo mortality. A third hypothesis is that elevated levels of OCs could trigger increased parental investment (terminal investment) which may represent an abortive strategy for OC contaminated gulls, further aggravating the negative impact of OCs on gull population parameters.

• Blight, L.K.  Egg production in a coastal seabird, the glaucous-winged gull (Larus glaucescens), declines during the last century.  PLoS ONE 6(7): art. e22027, 2011.
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  Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y^-1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008-2010) 7 d later than in previous studies (1959-1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ~50-100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas.

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