City slicker seagulls prefer junk food to fresh fish: biologists

People are fed a daily diet of television programs about the battles between healthy and junk food.

Scientists in Britain though have gone one further with one of the most unusual "taste tests" ever conducted.

They fed fast food and natural diets to groups of seagulls living in an urban city center environment and also to those inhabiting a coastal area.

And their results have caused astonishment.

The city center black-headed seagulls preferred their usual junk food, even when fresh seafood was on the table. Some kilometers away on the coastline facing the Irish Sea, the gulls were also offered the same menu choice, and stuck to their usual seafood diets.

Marine biologist Jonathan Green, a senior lecturer at the University of Liverpool, said the taste test also revealed another amazing result. The urban gulls switched to a more natural seafood diet when they were feeding their chicks.

The researchers at the university used crumbled white bread as the main base of an urban diet and fresh sprats as examples of anthropogenic and natural food sources, to demonstrate that the preference for human food increases with the level of urban development.

Across the 11 study sites along a coastline in northwest England, the selection of natural food eaten by the gulls reduced as the feed sites became more urban, showing the gulls prefer the food most likely to be found in their immediate environment.

Urban birds in Liverpool city center were the most tolerant of humans, allowing the city slicker gulls to take advantage of fast food more quickly than their country and seaside cousins.

One concern among marine biologists was the fast foods the gulls learned to recognize and rely on might lack the important nutrients found in fresh fish and other natural foods.

Green said: "People think of gulls as pests in the urban environment, but urban breeding and foraging areas have become really important sites for these highly intelligent and adaptable species which are otherwise in decline. Our work shows the importance of conserving natural food supplies, as ultimately these will provide more stable and sustainable habitats for these birds."

Green told Xinhua: "In our tests we supplied the same food to gulls in a variety of locations from the city center to rural coastline over a month long period. Given the choice of urban human food over a natural fish diet, the city gulls stuck with the urban food and ignored the fish.

"It is clear the gulls in our tests had adapted to their food supply, but they are highly intelligent. It could well be the city center gulls realize humans are not a threat so can happily collect human food," he added.

Green said the test was important because a number of breeds of gulls are endangered and a study of their eating habits and lifestyle is important. Enditem