Some seagulls thrive in urban areas due to bigger brains

Seagull species that have bigger brains are more likely to nest on coastal cliffs and may also be better adapted to breed in urban environments such as on the roofs of buildings.

New research has found that more than half of cliff-nesting gull species have been recorded as nesting in towns and cities, compared to just 11 percent of those that do not, and these species have bigger brains than their non-cliff-nesting counterparts.

The findings come in a broad-ranging study by ecologists at the University of Exeter looking at potential relationships between brain size, wing shape, nesting habits and the use of urban areas.

It suggests that species such as the Herring Gull, the Lesser Black-backed Gull and the Black-legged Kittiwake possess a behavioural flexibility that enables them to nest in more challenging locations.

“Many people will be familiar with gulls nesting and foraging in urban areas,” says lead author Dr Madeleine Goumas, formerly a Postdoctoral Research Associate in the Centre for Ecology and Conservation, based at Exeter’s Cornwall campus in Penryn. “It’s not something you might expect from a seabird, so we wanted to try to understand why they do it.”

Dr Goumas and the team searched research databases to find records of urban breeding and foraging among gulls and mapped the range of the different species.

Thirteen of the 50 gull species were recorded as using urban areas to breed, while 13 gull species are known as urban foragers – with nine both breeding and foraging. When they compared the figures for breeding with the known habits of the birds, the team identified 10 of the 19 (53%) cliff-nesting gull species among those found to have nested in urban settlements, whereas only three of 28 (11%) non-cliff-nesting species were found to have done likewise.