TY - JOUR
T1 - Breeding and foraging habitat are important in determining foraging ranges of sympatric generalist species
AU - Thaxter, Chris B.
AU - Quinn, Lucy R.
AU - Atkinson, Philip W.
AU - Booth Jones, Katherine A.
AU - Clark, Nigel A.
AU - Clewley, Gary D.
AU - Green, Ros M. W.
AU - O'Hanlon, Nina J.
AU - Johnston, Daniel T.
AU - Masden, Elizabeth A.
AU - Ross‐Smith, Viola H.
AU - Sage, Elspeth L.
AU - Scragg, Emily
AU - Taylor, Rachel C.
AU - Burton, Niall H. K.
AU - Humphreys, Elizabeth M.
N1 - © 2025 British Trust for Ornithology. IBIS published by John Wiley & Sons Ltd on behalf of British Ornithologists' Union.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
PY - 2025/10/7
Y1 - 2025/10/7
N2 - How far animals travel to gather food for offspring or themselves is a central component of ecology. Among birds, the ‘foraging range’ (straight-line distance between a central place and a destination) is used to assess potential interactions with anthropogenic stressors such as wind farms. Recent reviews have summarized marine foraging ranges for UK breeding seabirds. However, for species that span the terrestrial/marine divide (some gulls, terns, sawbills and divers), terrestrial ranges are unknown, as is an understanding of how ranges may vary by breeding colony and their surrounding habitat. Using global positioning satellite (GPS) telemetry, we studied the movements of Lesser Black-backed Gulls Larus fuscus and Herring Gulls L. argentatus from 11 and seven UK breeding colonies, respectively, over 12 years. We investigated the variation in foraging range using general mixed effects models with respect to: (i) terrestrial and marine environments; (ii) stages of the breeding season; and (iii) colony types according to habitat (natural: island, coastal, inland; and urban: coastal), accounting for sources of potential sampling bias. Lesser Black-backed Gulls had significantly larger ranges than Herring Gulls. During likely active nesting periods (incubation and chick-rearing: ‘true breeding’), marine foraging ranges of Lesser Black-backed Gulls (local mean 19.5 ± 23.1 km, max 175.5 km) were greater than terrestrial ranges (local mean 14.9 ± 15.9 km, max 145.4 km). By contrast, terrestrial ranges were largest for Herring Gulls (terrestrial, 9.1 ± 10.7 km, max 83.8 km; marine, 7.1 ± 8.1 km, max 74.4 km). For terrestrial environments, true breeding foraging ranges of Lesser Black-backed Gulls were smaller than during pre- or post-breeding phases, whereas for Herring Gulls the reverse was true. Marine ranges of both species were smallest during pre-breeding and largest during post-breeding phases. For both species, urban colonies had the smallest foraging range and island colonies some of the largest. Terrestrial and marine foraging ranges were predicted UK-wide based on colony type and breeding phase, highlighting concentrations of foraging range. This study provides more precise foraging range information specific to foraging environment, breeding stage and colony type than has currently been available, and will therefore help to reduce uncertainty in the consenting process for proposed developments as well as in licensing control of wild birds.
AB - How far animals travel to gather food for offspring or themselves is a central component of ecology. Among birds, the ‘foraging range’ (straight-line distance between a central place and a destination) is used to assess potential interactions with anthropogenic stressors such as wind farms. Recent reviews have summarized marine foraging ranges for UK breeding seabirds. However, for species that span the terrestrial/marine divide (some gulls, terns, sawbills and divers), terrestrial ranges are unknown, as is an understanding of how ranges may vary by breeding colony and their surrounding habitat. Using global positioning satellite (GPS) telemetry, we studied the movements of Lesser Black-backed Gulls Larus fuscus and Herring Gulls L. argentatus from 11 and seven UK breeding colonies, respectively, over 12 years. We investigated the variation in foraging range using general mixed effects models with respect to: (i) terrestrial and marine environments; (ii) stages of the breeding season; and (iii) colony types according to habitat (natural: island, coastal, inland; and urban: coastal), accounting for sources of potential sampling bias. Lesser Black-backed Gulls had significantly larger ranges than Herring Gulls. During likely active nesting periods (incubation and chick-rearing: ‘true breeding’), marine foraging ranges of Lesser Black-backed Gulls (local mean 19.5 ± 23.1 km, max 175.5 km) were greater than terrestrial ranges (local mean 14.9 ± 15.9 km, max 145.4 km). By contrast, terrestrial ranges were largest for Herring Gulls (terrestrial, 9.1 ± 10.7 km, max 83.8 km; marine, 7.1 ± 8.1 km, max 74.4 km). For terrestrial environments, true breeding foraging ranges of Lesser Black-backed Gulls were smaller than during pre- or post-breeding phases, whereas for Herring Gulls the reverse was true. Marine ranges of both species were smallest during pre-breeding and largest during post-breeding phases. For both species, urban colonies had the smallest foraging range and island colonies some of the largest. Terrestrial and marine foraging ranges were predicted UK-wide based on colony type and breeding phase, highlighting concentrations of foraging range. This study provides more precise foraging range information specific to foraging environment, breeding stage and colony type than has currently been available, and will therefore help to reduce uncertainty in the consenting process for proposed developments as well as in licensing control of wild birds.
U2 - 10.1111/ibi.13446
DO - 10.1111/ibi.13446
M3 - Article
SN - 0019-1019
JO - IBIS
JF - IBIS
ER -
