Seagulls may be known to scavenge a bit of food at the beach, or even steal something you’re snacking on if you’re not looking, but when it comes down to it, do they prefer human food or fish? A new study finds it may be the latter, at least for young birds.

Researchers at the University of Exeter recently investigated whether young herring gulls preferred urban food, like discarded human meals found in or near bins, or marine food. The question came about because past research has indicated that when adult gulls have hatchlings, they tend to switch to fish over bits of bread or fries they may find easily accessible.

To answer the question, researchers tweaked the diets of 27 rescued gull chicks reared in captivity and who were later released. Half were given access to bread and cat food for 80% of the day and access to fish and mussels for 20% of the day. The other half had the opposite schedule.

According to the findings, published in the journal PeerJ, all the chicks, regardless of dietary group, showed a marked preference for fish, with most refusing to eat bread. On days 5, 10, 15, and 35 of the study, all four foods were made available at the same time, and the fish-loving trend continued.

Emma Inzani, lead author from the Centre for Ecology and Conservation on Exeter’s Penryn Campus, says, “Our results suggest that, even when reared on an ‘urban’ diet of foods found only around people, these chicks might be unlikely to seek out urban foods as adults.

“Human-associated foods are often both reliably present and easy to obtain – but when fish is available they clearly prefer it.”

The team explains that with declining fish numbers in our oceans and easily accessible human foods in gulls’ territory, it may be less taxing to just settle for what’s easier. However, adults have been shown to prefer marine foods when they have hatchlings, possibly due to its nutritional return, so the findings reinforce the behavior observed in wild birds. They also show that whatever food is more available to gulls in their early life doesn’t necessarily impact their dietary preferences.

While the captive chicks went straight for the fish, it is still unclear whether wild chicks would do the same. It’s also unclear if their choices would continue into adulthood.

Dr. Neeltje Boogert, the study’s senior author, says, “Animals can live and exploit urban areas for human food waste. However, this does not necessarily mean they’re thriving or that they prefer this food, rather than making the best of a bad situation.

“More research is needed to investigate how the food young animals receive affects their later life, including their food choices, health and breeding.”

So, the next time a seagull snags your fries, you can be comforted by the thought that it may not be enjoying it that much.