14 research outputs found

    Global assessment of marine plastic exposure risk for oceanic birds

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    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

    Global assessment of marine plastic exposure risk for oceanic birds

    Get PDF
    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

    Roost temperature and fidelity of Wahlberg’s epauletted fruit bat, Epomophorus wahlbergi, in an urban environment

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    Generally,Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi) roost in trees or under the eaves of buildings. This study investigated the roosting dynamics of E. wahlbergi in the urban environment of Pietermaritzburg, South Africa. To determine roost fidelity bats were radiotracked to daytime roosts. Bats were found to change their daytime roosts regularly, and would change more frequently during winter than spring. Roost temperatures were measured by placing i-Button® temperature loggers at known roosts, either in man-made structures or vegetation. Temperatures varied across different roosts, but roost temperatures were generally higher than ambient temperatures. Roosts in man-made structures had higher temperatures than those in natural vegetation. This study showed the importance of temperature in E. wahlbergi daytime roosts, although other factors such as reproduction and social interactions, predator avoidance and proximity to food resources are likely to also affect selection of daytime roosts.Key words: Chiroptera, roost fidelity, fruit bat, urban environment, roost temperature,Epomophorus

    Seasonal differences in foraging dynamics, habitat use and home range size of Wahlberg’s epauletted fruit bat in an urban environment

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    Urbanization through the process of habitat loss and fragmentation affects  ecosystems. Many species are no longer able to survive in these urban areas; however, there are some that have been able to persist and even thrive in these habitats. One such species is Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi). Little is known about its existence in urban areas. Consequently we studied their seasonal variation in home range size, movements and foraging dynamics in the urban environment of Pietermaritzburg, South Africa. In a pilot study in summer, adult fruit bats (n = 8) were caught, fitted with radio-transmitters, and their movements followed for 12 nights and days. Although their movements varied considerably, no bats left the urban environment. Some of the larger distances covered in a single night were 2 and 5 km. In winter, an additional ten adult fruit bats were caught and fitted with radio-transmitters. Movements were followed for three weeks during winter and spring respectively. Winter home range size was greater than spring home range size. During winter the bats fed mostly on syringa fruits (Melia azedarach), an alien invasive, while their diet in spring was more varied and included species of indigenous and exotic fruits. The reduced variety of fruit eaten in winter may be explained by a reduction in fruiting plant  species, and thus a reliance on a few species to meet their dietary requirements. The bats would have a role in seed dispersal but therein lies the problem of them also dispersing invasive plants. Further research is needed to assess the role played by exotic and alien plant species in the continued success of urban wildlife, in particular fruit bats. The seasonal variation in home range size gives insight into the urban movements of Wahlberg’s epauletted fruit bats. The use of exotic and invasive plants by these bats is also significant.Key words: Chiroptera, fruit bat, urban environment, home range, roost sites, seasonal differences, movement

    Global assessment of marine plastic exposure risk for oceanic birds

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