In recent summers HiDef have worked on a range of projects counting urban nesting gulls.
Traditionally many gulls have nested in cliff and coast environs but changes in behaviour (both by gulls and humans) have seen increasing numbers nesting in towns and cities. Establishing where and how large these populations are is complex and the best way to monitor large areas is using digital video aerial surveys. In recent years, HiDef have flown five large scale urban areas under contract to UK agencies.
The flights are complex requiring additional authorisations to survey and create a complex mosaic for staff to locate birds in the video. Some nest on large open roof spaces, such as industrial units, while others tuck themselves into corners by chimneys making them trickier to find. Populations in some areas are large and are predominantly formed from herring and lesser-black backed gulls. HiDef data are passed onto JNCC, BTO, and Natural Resources Wales for calibration work against ground surveys and to create population models as part of a new census of nesting seabirds in Britain and Ireland.
Perhaps gull populations haven’t declined as much as is previously thought, and it is a simple ecological redistribution? We wait to see the outcome.
For more insight into urban gulls read:
Urban nesting Herring Gull Larus argentatus and Lesser Black-backed Gulls Larus fuscus population estimates: devising species-specific correction models for ground-based survey data
BTO: Urban gulls survey. Highlights from the 2018 Survey in Birmingham
JNCC: Seabird Census