Science.-City gulls know when and where to look for human food


A study with GPS trackers has revealed what has long been suspected: urban seagulls know exactly when and where to search for human food.

The University of Bristol research is the most in-depth analysis to date on the foraging behaviors of urban seagulls and how they have adapted to patterns of human activity in a city.

Compared to natural environments, urban environments are new to animals on an evolutionary time scale and present a wide range of possible food sources. In urban settings, food availability often fluctuates based on human activity patterns, which can follow a daily or weekly cycle. However, until now, little was known about how urban animals adapt to these time differences in the availability of food for humans.

A team of scientists from Bristol’s Colleges of Engineering and Life Sciences used different data to record the behavior of urban seagulls in three different settings in the city: a public park, a school and a waste center. The study used data from mini backpacks with GPS trackers installed on 12 black-backed gulls, as well as observations of the number of gulls at different sites.

The team found that the birds’ feeding patterns closely coincided with school vacation hours and the waste center’s opening and closing times, but that their activity in the park appeared to correspond with the availability of natural food sources.

These findings suggest that gulls may have the behavioral flexibility to adapt their foraging behavior to human schedules when beneficial, and that this trait helps them thrive in cities.

Dr Anouk Spelt, lead author of the Ibis article, International Journal of Avian Science, said in a statement: “Our first day at school, the students were excited to tell us about seagulls visiting their school at lunchtime. In fact, our data showed that seagulls were not only present in large numbers during lunchtime to feed on leftovers, but also just before the start of school and during the first recess when students had their snack. Thus, at the landfill, seagulls were present in greater numbers on weekdays when the center was open and trucks unloaded food waste.

“Although everyone has experienced or seen seagulls stealing food from people in parks, our seagulls mostly went to park first thing in the morning and this may be because earthworms and insects are present in greater numbers. amount during these first hours. “

“With this study in Bristol we have shown that gulls in cities can adapt their feeding schedule to make better use of food resources based on their availability. Some gulls even used all three feeding areas on the same day, which suggesting that they could track availability to optimize their energy intake. These results highlight the behavioral flexibility of seagulls and their ability to adapt to artificial environments and schedules of urban life. “