If you have ever been to a seaside town or city, you may have encountered herring gulls that are not shy about stealing food from humans.

These gulls are known to be opportunistic scavengers that can exploit a variety of food sources.

But how do they decide what is worth eating and what is not?

A new study by researchers at the University of Sussex revealed that gulls are not only greedy but also smart and observant.

They can watch the behaviour of humans and learn from their preferences.

Gulls prefer food that humans eat

The researchers wanted to test whether gulls can use social cues from humans to guide their foraging choices, as per Phys.org.

They conducted an experiment on Brighton Beach, where they placed two different colours of crisp packets (green for salt and vinegar, and blue for cheese and onion) on tiles a few metres away from gulls.

They then filmed the gulls' reactions while either eating from one of the packets themselves or just looking at the camera.

They found that when the researchers were eating crisps, more than twice as many gulls approached the packets, compared to when the researchers were not eating.

Furthermore, almost all of the gulls that pecked at the packets chose the same colour as the one that the researcher was eating.

This suggested that gulls pay attention to what humans are eating and use that information to select their own food.

The researchers also found that gulls were more likely to approach the packets when they were placed on tiles rather than directly on the sand.

This may indicate that gulls associate tiles with human-made objects and food sources.

Gulls are smart and flexible

The study shows that gulls are able to adapt to urban environments and exploit human resources.

They have a general intelligence and behavioural flexibility that allows them to learn from novel situations and cues, as per The Guardian.

The researchers believe that this ability comes from their evolutionary history as coastal scavengers that had to deal with changing food availability and competition.

The study also has implications for reducing human-gull conflicts, which are common in seaside towns and cities.

The researchers suggested that simply deterring people from feeding gulls may not be enough, as gulls can still observe what humans eat and target waste, litter and leftovers.

They recommend that people should also avoid letting gulls see them eat, or use containers or bags to conceal their food.

The study was published in the journal Animal Cognition. It is one of the first studies to demonstrate that gulls can use social cues from humans to make foraging decisions.

It adds to the growing evidence that gulls are highly intelligent and adaptable birds that can thrive in urban settings, as per The Irish Times.

In addition to their social learning skills, gulls also have other cognitive abilities that make them successful urban dwellers.

For example, they can recognize individual humans and avoid those who are hostile or threatening. They can also communicate with each other using various vocalisations and body signals. They can even cooperate with each other to steal food from larger predators or competitors.

Herring gulls are one of the most widespread and familiar species of gulls in North America and Europe.

They have a white head, neck, breast and belly, a light grey back and wings, black wingtips with white spots, yellow eyes with red rings, a yellow bill with a red spot, and pink legs.

They can live up to 30 years in the wild. They breed in colonies on cliffs, islands, rooftops or other structures near water, as per a-z animals, and feed mainly on fish, crustaceans, molluscs, worms, insects, eggs, chicks, rodents, carrion, and human food.

Herring gulls are not endangered or threatened, but they face some challenges as many other species, such as habitat loss, pollution, overfishing, climate change and human persecution.

They are also sometimes considered pests or nuisances by humans who dislike their noise, droppings or aggressive behaviour.

However, they also provide some benefits, such as scavenging waste, controlling rodent populations and attracting tourists.

Herring gulls are fascinating birds that deserve respect and appreciation for their intelligence and adaptability. They are not just greedy scavengers, but also smart learners who can watch and learn from humans.