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Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km2. Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km2) of the overall range. Average adult home ranges (286 km2) were only around 1% the size of the average foraging ranges of non-adults (10 540 –25 985 km2), with those of breeding adults being even smaller (95 km2). Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action.

The Tristan albatross Diomedea dabbenena is Critically Endangered: > 99% of adults breed at Gough Island, central South Atlantic Ocean, where chicks are threatened by introduced predators. At sea they mostly remain within the South Atlantic Ocean, where they are threatened by incidental capture in longline fisheries. Conservation measures to reduce seabird mortality in pelagic longline fisheries are confined largely to fishing effort south of 25°S. This covers the core range of breeding Tristan albatrosses, but the distribution of non-breeding adults and immature birds is unknown. We tracked 14 non-breeding adult Tristan albatrosses from Gough Island for up to 3 yr, from 2004 to 2006, using geolocating loggers. All birds remained in the South Atlantic or southern Indian Oceans, and showed distributions centred on the Sub-Tropical Convergence. They used the SW Atlantic during the austral summer and the SE Atlantic and Indian Oceans as far east as Australia during the austral winter. Foraging effort was concentrated in areas of upwelling and increased productivity. The distribution of the tracked birds overlapped with a range of pelagic longline fisheries, especially off southern Africa. Of particular concern was that 2 birds spent several months off the coast of Namibia and in adjacent high seas north of 25°S, where there are currently no regulations to prevent seabird bycatch during pelagic longline fishing operations.KEY WORDS: Atlantic Ocean · Indian Ocean · Longline · Bycatch · Diomedea dabbenena · Namibia Resale or republication not permitted without written consent of the publisherEndang Species Res 22: 39-49, 2013 of reliable data on bird bycatch. In addition, many species of seabirds range over vast areas and are thus likely to encounter multiple threats at sea in a variety of management jurisdictions (both national Exclusive Economic Zones [EEZs] and high seas areas) and to interact with fleets that vary widely in terms of compliance with conservation measures where these are in place.The Tristan albatross Diomedea dabbenena breeds almost exclusively on Gough Island in the central South Atlantic Ocean. It is classified as Critically Endangered by the IUCN because of population declines caused by mortality on longlines and predation of chicks by introduced mice Mus musculus (Wanless et al. 2007, BirdLife International 2012. The population is estimated to be decreasing by almost 3% yr −1 , with annual mortality from longline fishing estimated to be around 250 individuals (Wanless et al. 2009). Tristan albatrosses have been killed by pelagic longline fisheries off Brazil (Olmos 1997, Cuthbert et al. 2005) and southern Africa (Petersen et al. 2009). A recent assessment conducted under the auspices of the International Commission for the Conservation of Atlantic Tunas (ICCAT) concluded that the Tristan albatross was one of the species most at risk from longline fishing within the ICCAT area of jurisdiction (Tuck et al. 2011). A qualitative risk assessment for seabirds in the area managed by ...

Remote oceanic islands harbour unique biodiversity, especially of species that rely on the marine trophic resources around their breeding islands. Identifying marine areas used by such species is essential to manage and limit processes that threaten these species. The Tristan da Cunha territory in the South Atlantic Ocean hosts several endemic and globally threatened seabirds, and pinnipeds; how they use the waters surrounding the islands must be considered when planning commercial activities. To inform marine management in the Tristan da Cunha Exclusive Economic Zone (EEZ), we identified statistically significant areas of concentrated activity by collating animal tracking data from nine seabirds and one marine mammal. We first calculated the time that breeding adults of the tracked species spent in 10 9 10 km cells within the EEZ, for each of four seasons to account for temporal variability in space use. By applying a spatial aggregation statistic over these grids for each season, we detected areas that are used more than expected by chance. Most of the activity hotspots were either within 100 km of breeding colonies or were associated with seamounts, being spatially constant across several seasons. Our simple and effective approach highlights important areas for pelagic biodiversity that will benefit conservation planning and marine management strategies.

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Observations were made of seabird and zooplankton distribution in the waters adjacent to south-easternTasmania to examine correspondence at coarse scales (tens of kilometres). The distribution of seabirds was related mainly to changes in the water depth (and distance from land) over the length of the transect, whereas the distribution of zooplankton related to temporal changes. Significantly different associations of seabird species occurred in Storm Bay (mainly species breeding within the bay), and over the shelf-edge (with many non-breeding species dominant). Zooplankton diversity varied during the study, being greatest at the beginning (May) and end (September) of the study. Little correspondence was found between the distribution of seabirds and zooplankton at the community level, but there were significant relationships for several species, such as diving petrels and gannets. The lack of an overall correspondence between seabirds and zooplankton may have been due to the patchiness of seabird and zooplankton distribution, limits to the requirements of seabirds to find maximum prey densities (instead only needing to find ‘enough’), the lack of certainty about whether seabirds were foraging when observed, and behavioural interactions among seabirds.

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species.