Why Do Seagulls Steal Food? What Studies Show About Gulls

Food stealing is natural for gulls

Taking food from other animals has a scientific name: kleptoparasitism. Many gulls do it routinely. Herring gulls and great black-backed gulls chase terns, puffins and other seabirds returning to their colonies with fish, and black-headed gulls are well known for robbing puffins and lapwings. In North America, laughing gulls sometimes perch on the heads of brown pelicans to snatch fish from their pouches.

From a gull’s point of view, a person holding a pasty is not very different from a puffin holding a beak full of sand eels. Stealing saves the time and energy of hunting, and gulls are built to exploit any opportunity. The herring gull, the gull most often blamed in Europe, eats everything from crabs and worms to carrion, seeds and garbage.

Gulls learn that people mean food

Gulls are intelligent and long-lived, and they learn from experience. A gull that once got a handful of chips from a tourist, or found an open bin full of leftovers, will try again. Young gulls also watch and copy older birds.

Human food is especially rewarding. Fried food, bread and meat are packed with calories and easy to swallow, so one successful grab can be worth more than an hour of searching a beach. Feeding by people, deliberate or accidental, steadily teaches gulls to come closer.

There are also simply more gulls in towns than in the past. Since the mid-20th century, herring gulls and lesser black-backed gulls have increasingly nested on rooftops in coastal towns, where food from streets, harbors and landfill sites is close at hand. At the same time, many natural colonies on cliffs and islands have shrunk, so gulls are shifting from wild food toward town life.

What the University of Exeter studies found

Researchers at the University of Exeter’s Penryn campus in Cornwall, England, have run some of the best-known experiments on urban gull behavior.

Gulls watch where people look. In a 2019 study published in Biology Letters, Madeleine Goumas and colleagues placed a bag of food on the ground near a researcher, who either looked directly at a chosen herring gull or looked away. Only 26% of the gulls targeted came and touched the food at all. Among those that did, gulls took significantly longer to approach when the person was watching them. Individuals varied a lot: some were barely affected, while others hung back much longer when watched.

Gulls prefer food people have handled. In a 2020 study in Royal Society Open Science, the same team put two identical food items in front of free-living gulls. A researcher had handled one of them. The gulls more often pecked at the item the person had handled, suggesting they use human handling as a clue to where good food is. When the test was repeated with non-food objects, the gulls showed no such preference, so the cue seems to work specifically with food.

Together, these findings suggest that food snatching is done by a bold minority, and that gulls pay close attention to what people do with their food.

Why seaside gulls seem bolder in summer

Complaints about gulls peak from late spring to late summer. That is the breeding season, when parents must find food for themselves and for hungry chicks, and they also defend nests on rooftops by swooping at people who come close. It is also the busy tourist season, with many people eating outdoors on promenades and beaches.

Young gulls that have just left the nest add to the problem. They are inexperienced, hungry and often noisy, and they learn quickly from older birds that people are worth watching.

How to avoid losing your lunch

Simple habits greatly reduce the chance of a gull taking your food:

• Do not feed gulls, even with leftovers. It teaches them to approach people.
• Eat under cover or indoors where gulls gather, and keep food close to your body.
• Keep an eye on gulls nearby. Facing them may make some hesitate, as the Exeter research suggests.
• Put litter and leftovers in closed bins, or take them home.
• Avoid nests on roofs and ledges in spring and summer, when parents defend chicks.

Gulls are protected wild birds in the UK, the European Union and the United States, so the aim is to change the conditions that reward food stealing, not to harm the birds.

Myths and facts

Myth: All seagulls are thieves. Fact: the Exeter experiments found that most gulls would not approach food near a person; snatching is done mainly by a minority of bold birds.

Myth: Gulls steal because they are starving. Fact: gulls steal mainly because it works. Human food is easy and rich in energy, and a learned habit is hard to break.

Myth: Seagulls are one kind of bird. Fact: seagull covers many species, and food-snatching gulls in Europe are usually herring gulls. See Is a seagull a real species?