Seagulls ‘thriving’ in urban areas thanks to having bigger brains

By Lauren Beavis via SWNS

Experts say seagulls are 'thriving' in urban areas - due to having bigger brains.

New research shows the seagull species who 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.

According to ecologists at the University of Exeter, 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 have come from a broad-ranging study conducted by ecologists based at Exeter’s Cornwall campus in Penryn - which has explored 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 behavioral flexibility that enables them to nest in more challenging locations.

Lead author Dr. Madeleine Goumas, formerly a Postdoctoral Research Associate in the Centre for Ecology and Conservation, said: "Many people will be familiar with gulls nesting and foraging in urban areas.

“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 fifty gull species were recorded as using urban areas to breed, while thirteen gull species are known as urban foragers – with nine both breeding and foraging.

Dr. Neeltje Boogert, Royal Society Dorothy Hodgkin Research Fellow, said: “We found that gull species with larger brains are more likely to be cliff-nesters, and cliff-nesting species are more likely to breed in urban areas.

“We also found that cliff-nesting is probably not something that was shared by the ancestor of gulls, so it is a relatively recent adaptation.”

However, Dr. Goumas explained this is not a fixed behavior in most gulls, as whilst "non-cliff-nesting species nest exclusively on the ground, most cliff-nesting species nest either on cliffs or the ground."

Dr. Goumas explained: "This suggests that bigger brains enable these gull species to be flexible with regard to where they choose to nest, and this allows them to use unconventional sites, like buildings, for raising their young.”

When it came to foraging, the researchers found that neither brain size nor the shape of the wing, which affects maneuverability, were robust indicators of seagull behavior in urban environments.

The researchers also looked into the status of the gulls on the International Union on Conservation of Nature and found that those with stable or increasing populations were more than twice as likely to have been recorded using urban habitats than those that are decreasing.

Of the ten Threatened or Near Threatened species, only one - the Black-legged Kittiwake - was known to use urban habitats.

Dr. Boogert said: “Whether or not species use urban areas has important implications for conservation.

“If we can understand the factors that allow animals to use urban areas, we can better understand how to help those that aren’t faring so well.”

The rise of urbanization has increased risks for a significant number of animals, causing the decline and extinction of many species.

Dr. Goumas added: “Urbanisation is a major problem for a lot of animals.

“It looks like some gull species have managed to overcome some of the challenges that prevent other animals from using urban areas, but we need more long-term studies as well as comparative studies on other taxa to fully understand the impacts of urban living.”

The study has built on a body of research conducted by the team on gull behaviour, including how they favor food humans have handled and how staring at them makes them less likely to steal your food.

'From the Sea to the City: Explaining gulls’ use of urban habitats' has been published in the latest edition of Frontiers in Ecology and Evolution.