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Little is known on seabirds of the order Procellariiformes which visit the Brazilian oceanic islands. Herein, we present new records of five birds found stranded in the Fernando de Noronha archipelago: Fregetta tropica melanoleuca Salvadori, 1908, Ardenna grisea (Gmelin, 1789), Puffinus lherminieri Lesson, 1839, and Hydrobates leucorhous (Vieillot, 1818). Citizen‑science platforms include only one documentation for each of these species, but there is potential for greater detection. Pelagic birds have rarely been reported in recent decades, and continued monitoring is needed for better understanding of their distribution patterns.

The Santos Basin in eastern Brazil is adjacent to the largest human populations in the southwestern Atlantic Ocean, with several potential threats to marine vertebrates. In this study, we provided a systematic bibliographic review and integrated unpublished primary datasets to provide an overview on species, research topics and gaps, and threats to seabirds in the Santos Basin. Bibliographical sources were used for species recorded within the limits of the basin, while species census data were obtained through research and monitoring projects. We analyzed 156 studies from 1914 to 2021. An increase in the number of publications was observed from the 2000s onward (> 80%), with the state of Santa Catarina showing the highest number of publications (56%) on seabirds. Notes and Records (27%), Population and Community Structure (22%), and Fishing (11%) were the main subjects studied. Among the 76 seabird species reported in the Santos Basin (~2/3 of the species reported in Brazil), Procellariiformes was the most prevalent order (51%), including 14 species listed as threatened, either globally or nationally. Resident (28%) and long-distance migratory species, such as visitors from the Southern (39%) and Northern (17%) Hemispheres and Europe (12%), were widely recorded in the region, as well as vagrant species. The inclusion of different data sources allowed broadening the geographic cover used by species to consider both coastal (predominating in previous studies) and offshore areas. The association of seabird distribution with oceanographic and meteorological features should be addressed in future studies, as should studies on the impact of fishing and pollution on a range of common species. [ABSTRACT FROM AUTHOR]

Aim: Decision‐making products that support effective marine spatial planning are essential for guiding efforts that enable conservation of biodiversity facing increasing pressures. Key Biodiversity Areas (KBAs) are a product recently agreed upon by an international network of organizations for identifying globally important areas. Utilizing the KBA framework, and by developing a conservative protocol to identify sites, we identify globally importants places for breeding seabirds throughout the coastal seas of a national territory. We inform marine spatial planning by evaluating potential activities that may impact species and how a proposed network of Marine Management Areas (MMAs) overlap with important sites. Location: Southwest Atlantic Ocean. Methods: We collated a national inventory of all breeding locations for seabirds, including abundance records where available, and complementary estimates of at‐sea distribution. We delineated areas of importance in coastal seas following approaches tailored to the ecology of species and assessed areas against global KBA criteria. To determine opportunities for species conservation and management, we reviewed which human activities have been documented to impact the target species globally via IUCN Red List accounts, and also assessed the overlap of important sites with a proposed MMA network. Results: We identified global KBAs for nine seabird species (Anatidae, Diomedeidae, Laridae, Procellariidae, Spheniscidae, Stercorariidae) throughout national coastal seas. Globally important areas where multiple species overlapped were only partially accounted for in key zones of the proposed MMA network. Main Conclusions: Development of a conservative protocol to identify marine sites for assessment against KBA criteria, revealed opportunities for enhancing a network of proposed Marine Management Areas in coastal seas. The framework we apply in this study has broad relevance for other systems where the design or review of management plans for the marine environment is required. [ABSTRACT FROM AUTHOR]

There are growing pressures on marine biodiversity. Seabirds in particular are one the most‐threatened groups. The black‐vented shearwater (Puffinus opisthomelas) is endemic to Mexican islands and the only shearwater living its entire life cycle in the California Current System, one of the most productive large marine ecosystems in the world. Marine Protected Areas (MPAs) in this region, however, were designed without consideration of accurate data on seabird distributions.Here, 57 black‐vented shearwaters were GPS‐tracked from their main breeding colony (95% of the global population) over four seasons (2016–2019) to estimate their at‐sea distribution. Two methods were applied to identify priority conservation areas: the approach developed by BirdLife International to identify marine Important Bird and Biodiversity Areas and a method using expectation‐maximization binary clustering to identify core foraging areas.One potential marine Important Bird and Biodiversity Area close to the breeding colony and five core foraging areas were identified. These priority conservation areas were largely beyond the bounds of the current MPA network in the region.Our results detail opportunities for improving the implementation of conservation and management measures in the California Current System region with respect to seabirds. The approach of combining site identification methods can be applied to other seabird species for which high‐resolution tracking data are available and can help guide conservation action plans and MPA design. [ABSTRACT FROM AUTHOR]

Gadfly petrels (genus Pterodroma) are one of the most threatened groups of birds. They are exceptionally well adapted to forage over enormous areas to maximize chances of encountering prey. Their wide-ranging travel, extensive use of oceanic habitats beyond national jurisdictions (the high seas), and limited information on their at-sea distributions and foraging ecology pose several management challenges. Here, we examined the foraging distributions and habitat preferences of three gadfly petrels that breed on Phillip Island (Norfolk Island Group), in the southwest Pacific Ocean, and tested the ability of species distribution models (SDMs) to predict important marine habitats. GPS loggers were deployed in 2018 and 2019 on chick-provisioning black-winged petrels (P. nigripennis) and white-necked petrels (P. cervicalis) and in 2020 on Kermadec petrels (P. neglecta), and hidden Markov models (HMMs) were used to estimate behavioral states across 387 foraging trips. SDMs were built using six algorithms and the predictive performance of models constructed using conventional random cross-validation (CV) was compared to those constructed with spatially independent CV. All three species demonstrated dual-foraging strategies with short trips closer to the colony and longer, presumably self-provisioning, trips with maximum distances from the colony of several thousand kilometers for black-winged and white-necked petrels. Foraging areas of each species were distinctly partitioned across the Tasman Sea during long trips, but there was high overlap during short trips. Black-winged and white-necked petrels exhibited area-restricted search foraging behavior throughout their foraging ranges which spanned almost the entire Tasman Sea and into the western Pacific, whereas the foraging range of Kermadec petrels was restricted closer to the colony. Approximately half of each species’ foraging range extended into the high seas. Response curves and variable importance between the two SDM CV approaches were similar, suggesting that model fitting was robust to the CV approach. However, evaluation using spatially independent CV indicated that generalizability of ensemble SDMs to new data ranged from poor to fair for all three species. This suggests that the maximal-area foraging strategy of gadfly petrels (whereby they search opportunistically for resources across expansive oceanic habitats) results in weak or wide associations with environmental features making predicting important habitats extremely challenging.

Most seabirds forage far from land, making them hard to observe when foraging. Satellite tracking of seabirds shows where they come into conflict with human uses of the ocean, and whether they use protected areas. Because tracking data are expensive, data from one colony and/or year are sometimes used to design marine protection for a species across its range. Two assumptions commonly made are that foraging distance increases with colony size and individuals are uniformly distributed around colonies. We tested these assumptions using Magellanic penguins Spheniscus magellanicus as an example. We used a large tracking dataset of 338 penguins foraging for chicks at 10 colonies in Argentina from 1996 to 2019. Foraging distance increased with population size among colonies, but predicted distances would not cover foraging areas for all colonies. There was no relationship between population size and foraging distance within colony among years for colonies with ten and 23 years of data. Penguins were not uniformly distributed around colonies. Penguins used ~24% (12-40%) of the ocean available within the colony’s maximum foraging distance. We also show that overlap between penguin foraging areas and marine protected areas (MPA) and hydrocarbon concessions varied among colonies partly because of variation in how far offshore penguins forage. Overlap with MPAs was low (0% – 20%) for seven of the ten colonies and high (23% – 100%) for the other three. Overlap with a large area permitted for hydrocarbon exploration (seismic surveys) was relatively high (23% – 81%) for seven colonies where penguins forage offshore. Data from one colony are unlikely to indicate the most effective marine spatial planning for all colonies. Our data show that to be effective, marine planning should consider the temporal and spatial dynamics of ocean conditions and the response of marine wildlife to these changes. Climate variability is predicted to increase, making knowledge of foraging-location variation among colonies and years critical to conservation planning.

Seabirds inhabiting vast water masses provide numerous examples where opposing phenomena, such as natal and breeding philopatry vs. vagility have dug cryptic taxonomic boundaries among closely related taxa. The taxonomy of little shearwaters of the North Atlantic Ocean (Little–Audubon's shearwater complex, Puffinus assimilis – lherminieri) still remains unclear, and complementary information on non-breeding distributions and at-sea behaviour becomes essential to unravel divergent local adaptations to specific habitats. Using miniaturized light-level geolocators from seven study areas in the North Atlantic, we evaluate the spatial and habitat segregation, estimate the timing of their key life-cycle events and describe the at-sea behaviour of three taxa of these little shearwaters year-round to distinguish ecological patterns and specializations that could ultimately unravel potential lineage divergences. We also assess morphometric data from birds that were breeding at each study area to further discuss potential adaptations to specific habitats. Our results show that, while birds from different taxa segregated in space and habitats, they share ecological plasticity, similar annual phenology and diel foraging behaviour. These ecological inconsistencies, while defining the evolutionary stressors faced by these taxa, do not suggest the existence of three Evolutionary Significant Units. However, they confirm the recent evolutionary divergence among the three little shearwaters of the North Atlantic. [ABSTRACT FROM AUTHOR]

Seabird distributions are determined by physical and biological factors operating at variable scales and levels of ecological organization. Accordingly, changes in the composition of the marine avifauna often correspond to large-scale (macro-mega) shifts in water mass properties. Yet, few studies have addressed biogeographical patterns across multiple current systems, spanning from highly productive to oligotrophic waters. In this study, we characterize the at-sea assemblages of nesting seabirds across the Eastern South Pacific Ocean (ESPO), a vast region spanning from the Humboldt Current to the South Pacific Gyre. Employing multivariate techniques, we first identify four distinct species assemblages and then relate their distributions to the underlying environmental conditions. Our results show that Julian day, depth, sea surface temperature (SST), sea surface salinity (SSS), and chlorophyll-α concentration are the most important factors explaining the distribution patterns of these assemblages. Moreover, environmental conditions also explain overall seabird abundance and species richness, two community-level characteristics indicative of ocean productivity. Seabird abundance was best explained by four variables, associated with onshore–offshore gradients (distance to the coast, ocean depth), and the influence of coastal upwelling (mean mixed layer depth, SSS). Richness was best explained by seasonality (Julian day) and by the presence of water mass boundaries (SST coefficient of variation). Our findings underscore the importance of environmental factors structuring the distribution and biogeography of seabirds across gradients of ocean productivity and water mass properties. Understanding the environmental drivers of seabird abundance and richness in the ESPO will inform the prioritization and design of effective marine conservation measures in this poorly studied region.

The Black-capped Petrel Pterodroma hasitata is a pelagic seabird with a dangerously small population size. Remaining breeding sites are threatened by habitat loss, introduced predators, and direct harvesting. The species likely also faces several threats at sea, but because knowledge of its distribution range and ecology is meagre at best, it is challenging to take concerted action to improve its conservation status. The species is currently known to breed only on Hispaniola (in the northern Caribbean Sea), but most at-sea observations are from the Florida Current and the Gulf Stream off the southeastern coast of the USA. Within the Caribbean Sea, observations are scarce. We compiled a database of at-sea sightings of Black-capped Petrels in the Caribbean Sea from 1953 to 2018 by thoroughly reviewing published and unpublished records (Appendix 1); here, we add to the literature 12 new records from a research cruise conducted in February 2018 across the Caribbean Sea. Our database was augmented with recently published information from three birds that were fitted with tracking devices. Based on the collected information, we argue that the existing distribution maps of Black-capped Petrels need adjustments. We show that Black-capped Petrels have been recorded throughout the central parts of the Caribbean, from the known breeding sites in the north down to coastal waters off Panama, Colombia, and Venezuela. However, the birds probably forage only in small parts of the Caribbean Sea (i.e., the coastal upwelling zones off Hispaniola and Cuba in the north and off the South American mainland in the south). The waters in between (i.e., in the central Caribbean Sea) appear to be mainly used as a corridor, while the eastern and western parts are unimportant. This indicates that certain hotspots within the Caribbean Sea may be more important to this endangered species than previously thought. [ABSTRACT FROM AUTHOR]

The distribution of wildlife informs conservation planning. In marine systems, spatial information for seabirds is acquired primarily using vessel-based at-sea survey, aerial survey or animal-borne tracking devices. Many factors contribute to geographic biases in marine spatial research and we use a structured database search to review global patterns resulting from these biases. Although survey effort has been substantial, many large marine sectors were poorly represented. Poor representation often coincided spatially with hotspots of seabird species richness or areas experiencing high cumulative human impact, particularly in southern hemisphere and equatorial regions. Therefore, future seabird research priorities should reflect high species-richness areas including the south-west Pacific, particularly waters surrounding New Zealand. Furthermore, under-represented areas of Asia, and the Atlantic coasts of South America and Africa require greater research effort because of high cumulative human impacts in these areas. National gross domestic product (GDP) was positively related to the number of papers a country produced (determined by the first author’s address). This is indicative of constraints imposed by inherent costs of marine research. We recommend international collaboration between scientists from high-GDP nations with those in developing countries to address this. Further uptake of platforms of opportunity may also reduce this imbalance. [ABSTRACT FROM AUTHOR]

Studies of the at‐sea distribution and trophic ecology of penguins are essential to understand their role in the broader marine food web. Magellanic Penguins Spheniscus magellanicus have a wide distribution and their foraging behaviour varies across breeding sites and between sexes, among others. In this study, we characterized the at‐sea areas, the diving strategies and the relative trophic level of Magellanic Penguins breeding at Isla de los Estados, Argentina, during the early chick‐rearing period. In addition, we quantified the interannual, sexual and individual variability in those parameters during three breeding seasons (2011–2013) using devices recording position and dive depth, and obtained blood samples for stable isotope analysis. During the early chick‐rearing period, Magellanic Penguins showed small differences between the sexes in their foraging behaviour and large overlap in the at‐sea areas used, suggesting no intraspecific variation between sexes. Although there was interannual variability in the foraging behaviour and the trophic level of the penguins, most of the studied nests managed successfully to raise both chicks during the first stage of the breeding cycle (guard stage). The foraging ecology of Magellanic Penguins from this colony was comparable with results of past studies at other breeding colonies. This study contributes to the identification of important at‐sea areas for Magellanic Penguins at the southern edge of their distribution and also to the identification of possible threats in the study area such as interaction with fisheries. [ABSTRACT FROM AUTHOR]

Migration is a fundamental aspect of the ecology and evolutionary history of many animals, driven by seasonal changes in resource availability and habitat structure. Seabird migration has been investigated extensively in highly seasonal temperate and polar environments. By contrast, the relationships between migration and seasonal environmental changes have rarely been studied in tropical marine habitats. The sooty tern Onychoprion fuscatus is the most abundant tropical seabirds, and has been ranked as the most important tropical species in terms of its annual estimated consumption of marine resources. We used global location sensing (GLS loggers) to describe for the first time the year-round at-sea distribution and activity patterns of sooty terns from a large breeding colony in the western Indian Ocean (Bird Island, Seychelles). While breeding, they foraged within 1,074 ± 274 km of the colony. After breeding, birds undertook an extensive post-breeding migration throughout the Indian Ocean; average distances traveled exceeded 50,000 km per individual. Sooty terns used mainly four distinct core oceanic areas during the non-breeding period; in the Bay of Bengal (A), northeast to an area straddling the Chagos-Laccadive plateau (B), southeast to an area on each side of the 90 East Ridge (C) and southwest to an area around Comoros (D). Individuals exhibited a high degree of fidelity to these core areas in successive years. We also established that they performed an unusual behavior for a non-Procellariiformes seabird; most individuals undertook a 1-month pre-laying exodus, during which they foraged in a specific area c. 2,000 km to the south-east of the colony. Year-round at-sea activity of sooty terns revealed that they spent only 3.72% of their time in contact with seawater, so indicating that they must sleep in flight. Activity parameters exhibited seasonal (breeding vs. non-breeding periods) and daily variations; they notably never land on the water at night. In the Seychelles, breeding sooty terns are threatened by commercial egg harvesting. Our discovery of extremely wide non-breeding at-sea distribution highlights the risk of other threats during their non-breeding period, such as over-fishing, marine pollution and climate change.

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We describe the migration routes and non-breeding areas of Common Terns (Sterna hirundo) from the Azores Archipelago, based on ringing (banding) recoveries and tracking of three birds using geolocators. Over 20 years, there have been 55 transatlantic recoveries of Common Terns from the Azores population: six from Argentina and 49 from Brazil. The three tracked birds migrated south in different months (August, September, November), but the northern migration was more synchronous, with all leaving in April. The birds were tracked to three areas of the South American coast: the male spent November-April on the northern Brazilian coast (13°N-2°S), whereas the two females first spent some time off central-eastern Brazil (4-16°S; one for 1 week, the other for 3 months) and then moved south to the coast of south-eastern Brazil, Uruguay and northern Argentina (24-39°S). Although caution is needed given the small sample size and errors associated with geolocation, the three tracked terns potentially travelled a total of ~23 200 km to and returning from their non-breeding areas, representing an average movement of ~500 km day[sup -1]. With the exception of Belém, in northern Brazil, and Lagoa do Peixe, in southern Brazil, the coastal areas used by the tracked birds were also those with concentrations of ringing recoveries, confirming their importance as non-breeding areas for birds from the Azores. [ABSTRACT FROM AUTHOR]

Incidental mortality in fisheries is the main at-sea threat albatrosses are facing nowadays. In this study we used remote sensing techniques to model the degree of spatial overlapping between the Black-browed albatross (Thalassarche melanophris) and Argentine fisheries, assuming this as a proxy of risk for albatrosses. Eleven tags were deployed on albatrosses during the non-breeding seasons 2011 and 2012 in the Patagonian Shelf. Their distribution overlapped to different extents with the two coastal trawl, three offshore trawl and one demersal longline fisheries. The overlap index showed highest values with both coastal fleets, followed by the ice-chilling trawl fleet. These intersections were located in the Argentinean–Uruguayan Common Fishing Zone, in coastal areas of the SE of Buenos Aires province, El Rincón estuary and over the shelf break. The analysis of intersections of focal areas from albatrosses and all fisheries allowed the identification of thirty-four fishing management units (1° by 1° grid within the Argentine EEZ) classified as of medium, high or very high conservation priority. Very high priority units were placed between 35 and 38°S in the external mouth of Rio de la Plata, and between 45 and 47°S in neighboring waters East to the hake fishing closure. Although there were possible biases due to the limited number of tracked birds and the locations where albatrosses were captured and instrumented, the information presented in this study provides a comprehensive picture of important areas of overlapping during winter that could be used by the fishery administration to prioritize conservation actions under limited resource scenarios. [ABSTRACT FROM AUTHOR]

During the breeding season, seabirds act as central place foragers, constrained to foraging locations nearer to the breeding colony. Variability in energetic demands during phases of the breeding period has the capacity to shape foraging behaviour and influence at-sea foraging behaviour of seabirds due to the changing requirements of the young. Short-tailed shearwaters (Puffinus tenuirostris) (STSH) are a migratory species that migrates between foraging grounds in the northern Pacific Ocean and breeding colonies in south-east Australia. They are known to traverse large sectors of the Southern Ocean to find prey; however the at-sea foraging locations of this species are not spatially and temporally well defined during the breeding season, when energetic requirements are at their peak. We aimed to define key foraging areas of STSH over the pre-laying, incubation and chick-rearing phases of the breeding cycle and identify associations with broad scale oceanographic features. Using light-level geolocation archival tag technology, 27 adults from a southern Tasmanian colony were tracked from their arrival in October to March (2010–2011), providing information on a total of 77 pre-laying exodus, incubation and chick-rearing flights throughout the Southern Ocean. During the pre-laying exodus and incubation phases, the birds visited waters of the sub-Antarctic Front and Polar Frontal Zone. After hatching, the birds made direct flights to the Marginal Ice Zone between 155°E and 90°E. The Antarctic pack ice is a key nursery ground for Antarctic krill (Euphasia superba) over the winter months, and as the ice retreats they become more accessible to STSH when energetic demands, due to chick provisioning, are at their greatest. During late chick-rearing, the birds used waters in the region of the Antarctic Divergence. A foraging index created from activity data collected by the tags indicated that adults spent the greatest amount of time foraging at the furthest extent of each trip. This study has shown that STSH alter their foraging movements over the course of the breeding season, using areas that are likely to provide predictable food resources. [ABSTRACT FROM AUTHOR]

Central-place foraging seabirds increase food-loads and decrease meal frequency when they forage in areas that are distant from the breeding colony. In 2001–2002, we studied the seasonal changes in at-sea distribution, food-load mass, meal frequency, and fledging mass in rhinoceros auklets ( Cerorhinca monocerata), which forage in coastal waters during the day and feed their chicks at night. In both years, greater numbers of auklets were observed flying in northern waters that are more distant from the colony in June (65 km) and July (65–66 km) than in May (38–47 km). In July of both years, many auklets flew northward across the transect set 65–120 km north of the colony at sunrise; the birds returned south again at sunset, indicating that they foraged in waters outside the study area. This seasonal northward movement of the foraging area may reflect the migration of their main prey item, the Japanese anchovy ( Engraulis japonicus), which move with the Tsushima Warm Current flowing from the southern Sea of Japan. Food-load mass did not increase seasonally. In both years, the estimated daily meal frequency was lower in July than in May or June, partly because of the increased foraging distance in July. Late-hatched chicks also displayed lighter fledging masses than early chicks in both years. We suggest that late breeders are required to forage at great distances for longer periods, which may result in decreased meal frequency and lighter fledging mass of their chicks. [ABSTRACT FROM AUTHOR]

The article presents the study on the behavior and at-sea distribution of the tropical pelagic seabird in the western Indian Ocean. The study aims to determine the movements of the Puffinus pacificus using the global location sensing (GLS) which are breeding in Aride Island, Seychelles. It found out that wedge-tailed shearwater has exploited the unproductive oceans and showed short-distance movements and most of its feeding activity is mainly focused in the daylight period. Information about the at-sea distribution of shearwaters quantifying the overlap with industrial fisheries is considered crucial in conserving the species and creating fisheries policies for the Indian ocean.

The expansion of human activities in offshore maritime regions has outpaced the development of scientific knowledge and cooperative governance across these areas beyond national jurisdiction (ABNJ). In this context, current negotiations by the United Nations aim for an international legally-binding instrument to improve governance and sustainable use of biodiversity in ABNJ. Penguins are among the most threatened seabird groups today, notably at sea from fisheries and oiling. Here, we examine the available information on penguins' movements and evaluate their use of ABNJ across species and life-cycle stages. We highlight that in most of the 18 extant penguin species, the birds may undertake spectacular migrations, seasonally or throughout life-cycle stages. Long-range movements were reported in 16 species, with trans-jurisdictional distribution in 14 species, including 13 in ABNJ. Species richness in ABNJ varied extensively according to oceanic region, and also varied according to season. Transboundary movements, notably to ABNJ, are thus remarkably prevalent among penguin species. Consequently, provisions of the treaty under negotiation may crucially benefit penguin conservation, notably by creating a uniform legal framework to designate protected areas in ABNJ, and by promoting the precautionary approach to extraction activities. However, the seasonally-dynamic utilisation of ABNJ by penguins supports the pertinence of adding innovative protection tools, such as mobile Marine Protected Areas, to the negotiations for a more adequate protection of marine biodiversity. Underlining penguins' remarkable connectivity to the high seas can thus further strengthen this instrument aiming to protect a global ocean commons heritage of mankind. [ABSTRACT FROM AUTHOR]