Bird Study

Capsule: Habitat fragmentation can contribute to population declines in farmland birds when increased isolation between sub-populations limits local connectivity, re-colonization of abandoned habitat and between-year recruitment. Aims: To check for such signatures of fragmentation in mobile grassland inhabitants, we studied natal and breeding dispersal, adult and yearling return rates, and local phenology of the fragmented and severely declining Northern Black Forest (Germany) population of the Meadow Pipit Anthus pratensis. Methods: We colour-ringed 153 adults and nestlings, representing almost the entire local breeding population in 2020–2022, then estimated movements and return rates based on 2041 re-sightings at 13 grassland patches. Results: Return rates were 52% for adults and 21% for yearlings. Adults arrived earlier than yearlings and showed greater site fidelity. Natal philopatry was low, with yearlings driving the resettlement of abandoned grassland patches. Post-breeding yearling dispersal exceeded that of adults by 4.2 km, on average, with foraging sites up to 18 km from natal patches. Conclusion: Despite spatial fragmentation of suitable grassland habitats, the Meadow Pipit population remained well-connected, and adult and yearling return rates matched those reported from larger and, presumably, more stable populations in the species’ core range. Our data were thus not consistent with a prime role of population fragmentation or non-breeding survival for the local population decline, but strengthen earlier indications of insufficient local productivity. This emphasizes the need for further restoration of high-quality breeding habitat.

This pilot study showed that DNA metabarcoding can detect supplementary food in the diet of Hawfinches, which differed spatially and between years but not between sexes. https://www.tandfonline.com/doi/full/10.1080/00063657.2025.2459851

During spring and summer 2023, the highly pathogenic avian influenza (HPAI) H5N1 virus caused mass mortality among colony-breeding gulls and terns in Poland. Surveys were primarily focused within breeding colonies of Black-headed Gulls Chroicocephalus ridibundus, an ‘umbrella species’ whose breeding colonies serve as nesting sites for other scarce gull and tern species. In total, during the survey period we recorded the deaths of at least 46 Common Gulls Larus canus, 21 Mediterranean Gulls Ichthyaetus melanocephalus, nine Caspian Gulls Larus cachinnans, two Herring Gulls Larus argentatus, 1,369 Common Terns Sterna hirundo, 42 Little Terns Sternula albifrons, three Black Terns Chlidonias niger, two Whiskered Terns Chlidonias hybrida and 35 Sandwich Terns Thalasseus sandvicensis. The most affected populations were those of Mediterranean Gulls (12% of the Polish breeding population) and Common Terns (16% of the Polish breeding population). Common Terns and Common Gulls were considered the most vulnerable species to longer-term negative population impacts. It is strongly recommended to monitor mortality and productivity of all gull and tern species during future breeding seasons, to determine the ongoing impact of HPAI.

Capsule HPAI H5N1 was documented for the first time in the subantarctic region on Bird Island, South Georgia, resulting in the mortality of Brown Skuas Stercorarius antarcticus, Gentoo Penguins Pygoscelis papua, Snowy Albatrosses Diomedea exulans, and Antarctic Fur Seals Arctocephalus gazella. Aims The spread of the HPAI H5N1 subtype has had dramatic impacts on numerous populations of wild birds and mammals. We describe a case study that can inform the management of HPAI for conservation practitioners and researchers globally. Methods We documented the detection, monitoring, and impact of the first known outbreak of H5N1 HPAI in the subantarctic region, at Bird Island in South Georgia (−54.3582, −36.5112) during 2023–2024. Deaths from HPAI were first suspected in September 2023 and later confirmed by genetic analysis. Results In total, 77 Brown Skuas, 38 Gentoo penguins, and 58 Snowy Albatrosses were suspected to have died from HPAI infection, and HPAI was confirmed in 5 dead Antarctic Fur Seals. Total mortality was unknown for all species, as other individuals will have been scavenged before discovery, or died at sea. Conclusion This case study provides lessons for the management, risk, safety considerations, and ethical decisions regarding animal welfare that may help guide research and management responses to HPAI outbreaks elsewhere, particularly in remote areas or in species of conservation concern.

Beetle consumption by heron and egret in UK