Gastro gulls face slim pickings - British Trust for Ornithology

Gulls’ feeding habits can prove controversial, as they continue to adapt to human environments.

Scientists from the British Trust for Ornithology (BTO) have been tracking gulls in Scotland, to understand the foraging behaviours of these often-misunderstood seabirds.

Human activities are changing natural habitats globally. This can often put pressure on wildlife by, for example, altering how species find food.

Some species, such as gulls, are highly adaptable and have learnt to change their diets and take advantage of the food on offer in human-altered environments. However, this can often bring them into urban areas, as well as increasing competition between individuals of the same, and different, species when high-quality food sources become scarce.

Gulls would have traditionally fed on natural food found around our shores before adapting to human activities. When the UK’s fishing industry was more buoyant than it is today, gulls gathered en masse at harbours where fish discards were freely available in large quantities. Landfill sites too swiftly became easy pickings, providing tons of accessible human food waste for the hungry birds to sift through. As we continue to change the way we dispose of such edible waste, these birds must now adapt again if they are to survive.

Researchers from BTO were keen to understand the foraging habits of closely related but distinct gull species to see if, and how, their searches for food differed.

The scientists attached GPS trackers to gulls at a nesting colony on the Isle of May, off Scotland’s east coast, to follow the birds’ movements when they went off in search of a meal, and to see if they were competing for the same food.