Wilson's Storm Petrel Research Articles

Assessing the trophic ecology and migration on the exposure of cape petrels and Wilson's storm petrels from Antarctica to perfluoroalkylated substances, trace and major elements

Chemical pollution is a global concern as contaminants are transported and reach even the remote regions of Antarctica. Seabirds serve as important sentinels of pollution due to their high trophic position and wide distribution. This study examines the influence of migration and trophic ecology on the exposure of two Antarctic seabirds, Wilson's storm petrel (Oceanites oceanicus - Ooc), and Cape petrel (Daption capense - Dca), to chemical elements and perfluoroalkyl substances (PFAS). Our methodology involved assessing the concentration of these pollutants in feather samples obtained from carcasses, offering a practical means for monitoring contamination. Trace and major element concentrations were comparable in both species, suggesting that migratory patterns have a minimal impact on exposure levels. However, Ooc had higher concentration of PFAS compared to Dca (mean, ng g−1dry weight, PFOA: Ooc:0.710, Dca:0.170; PFTrDA: Ooc:0.550, Dca:0.360, and PFTeDA: Ooc:1.01, Dca:0.190), indicating that migration to the more polluted Northern Hemisphere significantly affects PFAS exposure. Furthermore, while no strong associations were found between either trace elements or PFAS and the three stable isotopes (δ13C, δ15N, and δ34S), a negative association was observed between PFUnDA and δ15N, hinting at potential biodilution. The research concludes that the migratory patterns of these seabird species affect their PFAS exposure, underscoring the critical need for further exploration and understanding of these relationships to better inform conservation strategies.

New insights on the phylogeny and genetic status of a highly vagile seabird from East Antarctica

Wilson's storm-petrel (Oceanites oceanicus, family Oceanitidae, order Procellariiformes) breeds in rock cavities along the ice-free coastline of Antarctica, a habitat susceptible to environmental change and human disturbance. Despite extensive presence, high numbers and wide-ranging movement, there are taxonomic ambiguities surrounding species' phylogenetic positioning and data gaps for most parts of its range. In this study, we provide support to the phylogenetic status of family Oceanitidae through new genetic datasets and modern analytical approaches. We generated mitochondrial cytochrome b gene sequences from samples collected from east Antarctica's ice-free regions. Reconstructed trees obtained using Bayesian and maximum likelihood models show Oceanitidae as a monophyletic group where Hydrobatidae (northern storm-petrels) appeared as a basal group to the order Procellariiformes. Phylogeographic network analysis resulted in seven distinct haplotypes with strong genetic differentiation (FST > 0.99) between east Antarctic and sub-Antarctic populations. Our study provides one of the first genetic datasets on Wilson's storm-petrel populations in east Antarctica. It serves as a baseline to undertake rigorous investigations into species' population structure, genetic connectivity and demographic responses to human-mediated changes in the austral environment.

Analysis of the attempts to breed seabirds in uninhabited territories of the Haswell archipelago and Adams Island (East Antarctica)

Data on new breeding sites of seabirds in Antarctica allow a better understanding of spatial species distribution, correct population estimates, and the processes occurring in populations and ecosystems. The aim of the work is to compile and analyze knowledge about the spatial distribution of breeding seabird populations and attempts to breed in new, previously uninhabited territories. Ground-based observations and population counts were conducted at the Haswell archipelago (Queen Mary Land, Davis Sea) by several observers from 1912 to 2016. The total area studied was 12 km². An aerial census of penguins on Adams Island was conducted in 2011. Based on this census, it might be stated that 6 out of 9 breeding species of seabirds have made attempts to develop new breeding sites. Regular breeding of birds within the archipelago is established on 8 islands. Emperor Penguins (Aptenodytes forsteri), Snow Petrels (Pagodroma nivea) and South Polar Skuas (Stercorarius maccormicki) showed no change in spatial distribution. Adélie Penguins (Pygoscelis adeliae), Southern Fulmars (Fulmarus glacialoides), Cape Petrels (Daption capense) and mixed pairs of Brown Skua (Stercorarius antarcticus) × ​​South Polar Skua bred in new sites (6 islands and 1 nunatak). New likely breeding sites have been recorded for the Southern Fulmar, Cape Petrel and Wilson's Storm Petrel (Oceanites oceanicus). An unsuccessful breeding attempt in a previously uninhabited territory has been observed in the Antarctic Petrel (Thalassoica antarctica). New breeding sites for seabirds may result from the avoidance of predation by South Polar Skuas. Changes in local meteorological conditions could be a factor contributing to the breeding attempts by seabirds in the territories previously uninhabited by them. The increase in South Polar Skuas populations, invasion of Brown Skuas on the Haswell Islands, increased breeding attempts and occupation of new breeding sites by Adélie Penguins and tube-nosed seabirds in the early 21st century are evidence of changes in ecological conditions in the local ecosystem.

Persistent organic pollutants and mercury in a colony of Antarctic seabirds: higher concentrations in 1998, 2001, and 2003 compared to 2014 to 2016

Over decades, persistent organic pollutants (POPs) and trace metals like mercury (Hg) have reached the remotest areas of the world such as Antarctica by atmospheric transport. Once deposited in polar areas, low temperatures, and limited solar radiation lead to long environmental residence times, allowing the toxic substances to accumulate in biota. We investigated the load of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDTs) and metabolites (DDEs, DDDs) in embryos from failed eggs of the smallest seabird breeding in Antarctica, the Wilson's storm-petrel (Oceanites oceanicus) at King George Island (Isla 25 de Mayo). We compared samples of different developmental stages collected in 2001, 2003, and 2014 to 2016 to investigate changes in pollutant concentrations over time. We detected eight PCBs including the dioxin-like (dl) congeners PCB 105 and 118 (ΣPCBs: 59-3403 ng g−1 ww) as well as 4,4’-DDE, and 4,4’-DDD (ΣDDX: 19-1035 ng g−1 ww) in the embryos. Samples from the years 2001 and 2003 showed higher concentrations of PCBs than those from 2014 to 2016. Concentrations of DDX was similar in both time intervals. Furthermore, we determined Hg concentrations in egg membranes from 1998 to 2003, and 2014 to 2016. Similar to PCBs, Hg in egg membranes were higher in 1998 than in 2003, and higher in 2003 than in the years 2014 to 2016, suggesting a slow recovery of the pelagic Antarctic environment from the detected legacy pollutants. Embryos showed an increase in pollutant concentrations within the last third of their development. This finding indicates that contaminant concentrations may differ among developmental stages, and it should be taken into account in analyses on toxic impact during embryogenesis.

Seabirds of human settlements in Antarctica: A case study of the Mirny Station

Antarctica is free of urbanisation, however, 40 year-round and 32 seasonal Antarctic stations operate there. The effects of such human settlements on Antarctic wildlife are insufficiently studied. The main aim of this study was to determine the organization of the bird population of the Mirny Station. The birds were observed on the coast of the Davis Sea in the Mirny (East Antarctica) from January 8, 2012 to January 7, 2013 and from January 9, 2015 to January 9, 2016. The observations were carried out mainly on the Radio and Komsomolsky nunataks (an area of about 0.5 km). The duration of observations varied from 1 to 8 hours per day. From 1956 to 2016, 13 non-breeding bird species (orders Sphenisciformes, Procellariiformes, Charadriiformes) were recorded in the Mirny. The South polar skuas (Catharacta maccormicki) and Adélie penguins (Pygoscelis adeliae) form the basis of the bird population. South polar skuas are most frequently recorded at the station. Less common are Brown skuas (Catharacta antarctica lonnbergi) and Adélie penguins. Adélie penguins, Wilson's storm petrels (Oceanites oceanicus), South polar and Brown skuas are seasonal residents, the other species are visitors. Adélie penguins, Emperor (Aptenodytes forsteri), Macaroni (Eudyptes chrysolophus) and Chinstrap penguins (Pygoscelis antarctica), Wilson's storm petrels, South polar and Brown skuas interacted with the station environment, using it for comfortable behavior, feeding, molting, shelter from bad weather conditions, and possible breeding. South polar and Brown skuas tend to be attracted to the station, while other Antarctic bird species are indifferent to humans. Birds spend part of the annual cycle at the station or visit it with different frequency, but they cannot meet their ecological needs there all year round. The study improves our understanding of the regularities of the phenomenon of urbanization of the avifauna in the polar regions of the planet Earth.

The Records of Wilson's Storm Petrel <i>Oceanites oceanicus</i>in the Northwest Pacific off Hokkaido

The Records of Wilson's Storm Petrel <i>Oceanites oceanicus</i>in the Northwest Pacific off Hokkaido

Sharing menus and kids' specials: Inter- and intraspecific differences in stable isotope niches between sympatrically breeding storm-petrels

Species sharing resources are predicted to compete, but co-occurring species can avoid competition through niche partitioning. Here, we investigated the inter- and intra-specific differences using stable isotope analyses in the black-bellied storm-petrel (Fregetta tropica) and the Wilson's storm-petrel (Oceanites oceanicus), breeding sympatrically in maritime Antarctica. We analysed stable carbon, nitrogen and oxygen isotopes in samples representing different life stages; chick down (pre-laying females), chick feather (chick), and adult blood (chick-rearing adults). Pre-laying females had wider stable isotope niches than chicks or chick-rearing adults, due to pre-laying females being free roaming while chick-rearing adults were central-place-foragers. Chicks were fed at a higher trophic level than the adults (higher δ15N), likely to compensate for the high nutritional demands of the growing chicks. Wilson's storm-petrels showed substantial overlap in stable isotope niches between all life stages, while the black-bellied storm-petrel chicks showed very little overlap. Wilson's storm-petrel niches significantly overlapped with those of pre-laying and chick-rearing black-bellied storm-petrels, suggesting negligible niche partitioning. Chick growth rate was negatively correlated with chick δ15N values, suggesting nutritional stress resulting in the use endogenous instead of dietary amino acids in protein synthesis. The higher trophic level of the relatively larger black-bellied storm-petrel chicks may be due to their longer stay in the nest, and relatively larger body mass gain, despite chick growth rates being similar to the smaller Wilson's storm-petrel chicks. Despite breeding sympatrically, the studied storm-petrel species showed considerable overlap in isotopic niches, which may be explained by sharing the same main prey species, reducing the detectability of foraging niche partitioning through stable isotope analyses. We found dietary shifts in black-bellied storm-petrels that are absent in Wilson's, showing different chick provisioning strategies, and shows that the high productivity of the Antarctic marine ecosystem may facilitate foraging niche overlap of sympatrically living species.

Storm petrels as indicators of pelagic seabird exposure to chemical elements in the Antarctic marine ecosystem.

Data on trace element bioavailability in the south-polar marine ecosystem is still scarce, compared to that relating to temperate zones. Seabirds can be used as indicators of ecosystem health and sentinels of environmental pollution, constituting a link between marine and terrestrial environments. Here, we analysed the concentration of 17 elements (with special emphasis on mercury, Hg) in feathers of adults and chicks of two pelagic seabirds - the Wilson's storm petrel Oceanites oceanicus and the black-bellied storm petrel Fregetta tropica - breeding sympatrically in the maritime Antarctic. Since adult feathers are formed during the non-breeding period away from the breeding grounds, but down and body feathers of chicks grow at the breeding sites, we were able to evaluate the birds' exposure to contaminants at various stages of their annual life cycle and in various marine zones. We found that of the two studied species, adult black-bellied storm petrels had significantly higher mercury, selenium and copper levels (5.47 ± 1.61; 5.19 ± 1.18; 8.20 ± 0.56 μg g-1 dw, respectively) than Wilson's storm petrels (2.38 ± 1.47; 1.81 ± 0.98; 2.52 ± 2.35 μg g-1 dw, respectively). We found that Wilson's storm petrel chicks had a significantly different contaminant profile than adults. Arsenic, bismuth and antimony were detected exclusively in the chick feathers, and the Se:Hg molar ratio was higher in chicks than in adults. Our study also suggests considerable maternal transfer of Hg (to down feathers) in both species. As global contaminant emissions are expected to increase, birds inhabiting remote areas with sparse anthropogenic pollution can indicate the temporal trends in global contamination.

Nest characteristics determine nest microclimate and affect breeding output in an Antarctic seabird, the Wilson's storm-petrel.

The importance of nest characteristics for birds breeding in the extreme climate conditions of polar regions, has been greatly understudied. Nest parameters, like nest orientation, exposure and insulation, could strongly influence microclimate and protection against precipitation of the nest, thereby affecting breeding success. A burrow nesting seabird, the Wilson’s storm-petrel (Oceanites oceanicus) is an excellent model species to investigate the importance of nest characteristics, as it is the smallest endotherm breeding in the Antarctic. Here, we investigated the effects of nest parameters such as internal nest dimensions, nest micro-topography and thermal properties of the nest burrow and the influence of weather conditions on breeding output, measured as hatching success, chick survival, and chick growth. We collected data during the austral summers of 2017 and 2018, on King George Island, maritime Antarctica. Our results showed that the thermal microclimate of the nest burrow was significantly improved by a small entrance size, a low nest height, and insulation and tended to be enhanced by a low wind exposition index and an eastern nest site orientation. In addition, an eastern nest site orientation significantly reduced the chance of snow blocking. However, the relationships between nest characteristics and breeding output were complex and might be affected by other parameters like food availability and parental quality. The relation between chick growth and nest air temperature remained especially indistinct. Nevertheless, our results indicate that nest characteristics that enhance the thermal microclimate and reduce the risk of snow blocking favoured both hatching success and chick survival. Due to climate change in the Antarctic, snowfall is expected to increase in the future, which will likely enhance the importance of nest characteristics that determine snow blocking. Additionally, despite global warming, thermally favourable nest burrows will likely still be advantageous in the highly variable and challenging Antarctic climate.

Cross-species screening of microsatellite markers for individual identification of snow petrel Pagodroma nivea and Wilson's storm petrel Oceanites oceanicus in Antarctica.

Seabirds are important indicators of marine ecosystem health. Species within the order Procellariiformes are the most abundant seabird species group distributed from warm tropical to cold temperate regions including Antarctica. There is a paucity of information on basic biology of the pelagic seabird species nesting on the Antarctic continents, and long-term studies are required to gather data on their population demography, genetics and other ecological parameters. Under the ‘Biology and Environmental Sciences’ component of the Indian Antarctic programme, long-term monitoring of Antarctic biodiversity is being conducted. In this paper, we describe results of cross-species screening of a panel of 12 and 10 microsatellite markers in two relatively little studied seabird species in Antarctica, the snow petrel Pagodroma nivea and the Wilson's storm petrel Oceanites oceanicus, respectively. These loci showed high amplification success and moderate levels of polymorphism in snow petrel (mean no. of alleles 7.08 ± 3.01 and mean observed heterozygosity 0.35 ± 0.23), but low polymorphism in Wilson's storm petrel (mean no. of alleles 3.9 ± 1.3 and mean observed heterozygosity 0.28 ± 0.18). The results demonstrate that these panels can unambiguously identify individuals of both species (cumulative PIDsibs for snow petrel is 3.7 × 10−03 and Wilson's storm petrel is 1.9 × 10−02) from field-collected samples. This work forms a baseline for undertaking long-term genetic research of these Antarctic seabird species and provides critical insights into their population genetics.

Facultative hypothermia as a survival strategy during snowstorm induced food shortages in Antarctic storm-petrel chicks

Wilson's storm-petrels (Oceanites oceanicus) are the smallest marine birds breeding in Antarctica, where events like snowstorms often prevent parents from providing food daily for their offspring. To minimize energy expenses, Wilson's storm-petrel chicks can reduce their metabolism and body temperature by entering hypothermia. Hypothermia is reported to impact development, hence we hypothesized that hypothermia will be majorly used after long fasting periods. Chick development in a breeding colony of Wilson's storm-petrels on the South Shetland Islands was monitored daily during three consecutive summers by recording chicks' body mass and temperature, as well as environmental parameters. Provisioning, and body conditions were highest in 2017, and chicks became hypothermic most frequently in 2016. Body temperature was influenced by age, mass, body condition, and minimal nocturnal temperatures. While most chicks were able to maintain stable body temperatures when not fed for one day, some chicks' body temperatures decreased by up to 21 °C. Age did not differ between those two groups, but chicks maintaining their active body temperatures had higher body conditions. Snowstorms were typically followed by several days of unreliable food provisioning and continuous days of fasting. Most chicks were hypothermic during this time, and were hence able to survive periods of food shortages, reverse their low body temperatures after the next feeding event, and regain body mass. We conclude that hypothermia is a strong survival strategy to endure times of fasting, which might be necessary for Antarctic storm-petrel chicks to reach adulthood. However, in future scenarios, which may include more frequent snowstorms due to climate change, malnourishment could lead to more frequent use of hypothermia, which could affect chicks' development.

Mercury exposure in a large subantarctic avian community

Mercury (Hg) contamination poses potential threats to ecosystems worldwide. In order to study Hg bioavailability in the poorly documented southern Indian Ocean, Hg exposure was investigated in the large avian community of Kerguelen Islands. Adults of 27 species (480 individuals) showed a wide range of feather Hg concentrations, from 0.4 ± 0.1 to 16.6 ± 3.8 μg g−1 dry weight in Wilson's storm petrels and wandering albatrosses, respectively. Hg concentrations increased roughly in the order crustacean- < fish- ≤ squid- ≤ carrion-consumers, confirming that diet, rather than taxonomy, is an important driver of avian Hg exposure. Adults presented higher Hg concentrations than chicks, due to a longer duration of exposure, with the only exception being the subantarctic skua, likely because of feeding habits' differences of the two age-classes in this species. High Hg concentrations were reported for three species of the poorly known gadfly petrels, which merit further investigation.

A feeding association between Wilson's Storm-petrels Oceanites oceanicus (Kuhl, 1820) and Rough-toothed Dolphins Steno bredanensis (G. Cuvier in Lesson, 1828)

On 06 October 2012 a pod of Rough-toothed Dolphins Steno bredanensis (Delphinidae) was observed catching and tearing apart several Castin Leatherjacks Oligoplites saliens (Carangidae) near Montão de Trigo Island, northern coast of São Paulo, Brazil. The resulting floating masses of viscera attracted a feeding aggregation of 120-150 Wilson's Storm-petrels Oceanites oceanicus (Hydrobatidae), a transequatorial migrant passing through the area during October. This interspecific association has not been recorded before, although it could be expected given that S. bredanensis feeds on large fish and O. oceanicus is a known scavenger of kills made by cetaceans such as Killer Whales.

Wilson's Storm-Petrel (Oceanites oceanicus)

Wilson's Storm-Petrel (Oceanites oceanicus)

Abundance and breeding distribution of seabirds in the northern part of the Danco Coast, Antarctic Peninsula

Seabird abundances and breeding distribution have the potential to serve as ecological indicators. The western Antarctic Peninsula is one of the three sites in the world with the greatest increases in local temperature during the last 50 years. The aim of this study was to monitor the distribution and abundance of breeding populations of seabirds in the northern sector of the Danco Coast, north-west of the Antarctic Peninsula, during the breeding season 2010/11. The birds were the Wilson's storm petrel ( Oceanites oceanicus ), South Polar skua ( Stercorarius maccormicki ), kelp gull ( Larus dominicanus ), Antarctic tern ( Sterna vittata ), snowy sheathbill ( Chionis alba ), chinstrap penguin ( Pygoscelis antarctica ), southern giant petrel ( Macronectes giganteus ), gentoo penguin ( Pygoscelis papua ), Cape petrel ( Daption capense ) and Antarctic shag ( Phalacrocorax bransfieldensis ). Annual breeding population growth increased in pygoscelids, southern giant petrel and sheathbill, and for the remaining species, breeding population trends were stable. Given that seabird populations can provide valuable information on the conditions of their feeding and nesting environments, this study highlights the need to maintain basics monitoring studies. Keywords: Seabird abundances; breeding distribution; Danco Coast; Antarctic Peninsula (Published: 28 February 2013) Citation: Polar Research 2013, 32 , 11133, http://dx.doi.org/10.3402/polar.v32i0.11133

A new storm-petrel species from Chile

ABSTRACT. We describe a new species of storm-petrel, Oceanites pincoyae (Pincoya Storm-Petrel), from the Puerto Montt and Chacao channel area, Chile. The description is based on 1 specimen collected at sea in Seno Reloncavi on 19 February 2011 and 11 other individuals that were caught, examined, and released. The new taxon's foraging ecology and behavioral habits are unique among the southern Oceanitinae, including “mouse-runs” and repeated diving beneath the surface to retrieve food items. Its distinctive appearance includes bold white ulnar bars, extensive white panels to the underwing, and white to the lower belly and vent. Among species of Oceanites, it is unique in showing white outer vanes to the outer two pairs of rectrices. It further differs from all other storm-petrels in having a distinctive juvenile plumage. Morphometrically it is distinct from Oceanites gracilis gracilis (Elliot's Storm-Petrel) and smaller than O. oceananicus chilensis (the Fuegian form of Wilson's Storm-Petrel), having a sho...

Moving polewards in winter: a recent change in the migratory strategy of a pelagic seabird?

BackgroundDuring the non-breeding period, many birds migrate to milder areas, found closer to the equator than their breeding sites. Opposite movements are very rare. In the Southern Ocean, the abundance of 13C declines markedly with more southern latitude, providing a characteristic 13C isoscape. This can be used as a tracer for the movement of seabirds between breeding and inter-breeding areas, by comparing stable isotope ratios of feathers grown at different times of the year.ResultsWe studied seasonal movements of Thin-billed prions (Aves, Procellariiformes), breeding at the Subantarctic Falkland/Malvinas Islands, compared with those of Wilson's storm-petrels breeding in the Antarctic South Shetland Islands. The two species showed opposite migratory movements. While Wilson's storm-petrels moved to warmer waters north of the Drake Passage in winter, Thin-billed prions showed a reversed movement towards more polar waters. Carbon stable isotope ratios in recent and historical feathers indicated that poleward winter movements of Thin-billed prions were less common historically (45% in 1913-1915), and have only recently become dominant (92% in 2003-2005), apparently in response to warming sea temperatures.ConclusionsThis study shows that pelagic seabirds can rapidly change migration strategies within populations, including migration towards more poleward waters in winter.

Estimation of feeding frequencies by periodic weighing of chicks: evaluation by video-observation of burrow-nesting Wilson's Storm-Petrels (Oceanites oceanicus)

We used video-observations of nesting burrows to determine if periodic weighing of chicks (once per day) accurately captured feeding events in Wilson's Storm-Petrel (Oceanites oceanicus). We found that, compared with video-recordings, periodic weighing and correction for metabolic loss correctly estimated whether a chick had been fed for 99.3% of all nights. It underestimated the number of feedings on 14.8% of nights and overestimated it on only 4.7%. The most common error in our study occurred in the discrimination between single and double feedings, classifying 22 (35.5%) of all double feedings as single feeding owing to their small size. However, the method gives good results at the population level, as the error rate (0.7% for fed v. unfed) is well below the variance in feeding rates observed between good and poor seasons. Thus, periodic weighing of chicks is an easy and reliable method for monitoring feeding rates, which is especially important in burrow-nesting species where a direct observation is difficult. We show that, following the establishment of a metabolic mass-loss curve by weighing chicks over short intervals, weighing of chicks once a day provides reliable results, and thus disturbance to feeding adults can be minimised. This can be especially useful in species where adults feed during a restricted time of the day, such as nocturnally.

An effective method for trapping scavenging seabirds at sea

ABSTRACT Most studies of seabirds that involve trapping and marking birds are carried out at breeding colonies. This bias toward the breeding period and colony-based research is partially caused by difficulties in capturing birds at sea. From 2005 to 2007, we used a cast net thrown by hand from a fishing boat to capture albatrosses and petrels at sea in the southwestern Atlantic Ocean. About 500 birds of 13 species were captured, ranging in size from the 30-g Wilson's Storm-petrel (Oceanites oceanicus) to the 10-kg Wandering Albatross (Diomedea exulans). Cast nets are potentially useful for capturing any seabird that can be attracted close to fishing vessels by bait, such as sardines, squid, offal, or shark liver, thrown into the water. Our method was most effective for capturing bold species, such as Cape (Daption capense), Spectacled (Procellaria conspicillata), and White-chinned (Procellaria aequinoctialis) petrels and Great Shearwaters (Puffinus gravis), but was not effective for capturing shy species, such as Cory's (Calonectris diomedea), Cape Verde (Calonectris edwardsii) and Manx (Puffinus puffinus) shearwaters, species that rarely sit on the water, such as Wilson's Storm-petrels, Thin-billed (Pachyptila belcheri) and Antarctic (Pachyptila desolata) prions and Atlantic Petrels (Pterodroma incerta), and species with excellent diving abilities, such as Sooty Shearwaters (Puffinus griseus). For many species of seabirds, cast nets would likely be more efficient for capturing large numbers of birds than other methods, such as hoop nets. La mayoría de los estudios sobre aves marinas son realizados en sus colonias de anidación. La dificultad para capturar aves en el mar en parte ha limitado el conocimiento sobre estas aves durante el periodo invernal. Entre 2005 y 2007 se empleó una red tipo atarraya para capturar albatros y petreles en el Océano Atlántico Sur Occidental. Fueran capturadas cerca de 500 aves de 13 especies y diferentes tamaños, desde el Petrel de las Tormentas de Wilson (Oceanites oceanicus) con solo 30 g de peso, hasta el Albatros Errante (Diomedea exulans) de 10 Kg. El método de captura es potencialmente aplicable a cualquier ave marina que se acerque a las embarcaciones pesqueras atraída por carnadas o descartes como sardinas, calamares, o hígado de tiburones. Este método fue más eficiente para la captura de especies confiadas, por ejemplo los Petreles Damero (Daption capense), de Antifaz (Procellaria conspicillata), Negro (Procellaria aequinoctialis) y la Pardela Capucho Negro (Puffinus gravis), pero no fue eficiente para la captura de especies tímidas cómo las Pardelas Cenicienta (Calonectris diomedea), de Cabo Verde (Calonectris edwardsii) y Común (Puffinus puffinus), para especies que difícilmente posan sobre el agua cómo el Petrel de las Tormentas de Wilson, Petreles Ballena de Pico Delgado (Pachyptila belcheri) y Ancho (Pachyptila desolata) y el Petrel Alas Negras (Pterodroma incerta), o especies con muy buena capacidad de buceo cómo la Pardela Negra (Puffinus griseus). Para muchas especies de aves marinas la red de atarraya es probablemente más eficiente para la captura en el mar que otros métodos que se han empleado como las redes de aro.

SEABIRDS IN THE BANDA SEA IN FEBRUARY/MARCH 1985

Quantitative seabird data were collected in February/March 1985 in the Banda Sea. Comparison with similar data for August 1984 indicated no monsoonal influence on seabrid abundance; the median for both periods falls within the 1-5 birds per hour class.The area around the breeding island Manuk was relatively rich in both periods. Birds breeding here are "blue ocean" seabirds, foraging over large areas. Apparently, not food abundance but suitable breeding place determines their abundance here. Manuk has an enormous importance for the seabird population in the Banda Sea area, fortunately, it is a nature reserve since 1981. The breeding period on Manuk is not short and related to the NE monsoon, but extended over a larger period of the year. Manuk was known already as a breeding island in the 17th cnetury, but this knowledge was lost and only recently Manuk was "rediscovered" as such.A second relatively rich area occurred again south of Irian Jaya. Migrating birds dominated here. They probably visit this area because of relatively high food availability. Species differed for both periods. Streaked Shearwaters which breed on the northern hemisphere had in February/ March replaced the antarctic Wilson's Stormpetrel which abounded here in August 1984, but had now returned to its breeding area.