The threat of having your ice cream or chips pilfered by a seagull will be familiar to anyone who goes on seaside holidays in the UK, but a study suggests there is a way to keep avian scavengers at bay: keep your eyes on them.
Madeleine Goumas at the University of Exeter and her colleagues ran an experiment with 19 seagulls in seaside towns in Cornwall. An experimenter placed a bag of chips on the ground and crouched behind it, 1.5 metres away. When a seagull approached the chips, she started a stopwatch, and either stared at the gull or looked in another direction.
When they were being watched, only 26 per cent of the gulls touched the chips. Those that did touch the food took around 20 seconds longer to do so when they were being watched.
This shows that seagulls are sensitive to the human gaze and change their behaviour when they are being watched. “Even though gulls seem like they do this a lot in some areas, it seems to be a few individuals that are responsible for the majority of food snatching,” says Goumas.
While gulls could have an ability known as theory of mind – the capacity to infer the mental states of others – a simpler explanation is that they learn to associate being watched with being chased away. It’s also possible that they have an innate fear of the human gaze.
Another unanswered question is whether natural selection is driving seagulls to be more audacious in urban environments. “We are going to continue studying them to find out more about them and how boldness and other personality traits might be advantageous or disadvantageous,” says Goumas.
Despite their ubiquity in seaside towns, herring gulls are on the UK’s red list for birds of conservation concern. Their population fell by 60 per cent from 1969 to 2015, and they are increasingly breeding in urban areas and relying on human food.
If you’re eating outdoors by the sea, Goumas’s advice is to sit with your back to a wall so gulls can’t approach from behind. Most importantly, be aware of your surroundings. “I often see people staring at their food or holding ice creams up in the air, and I think that’s just asking for it.”
Journal reference: Biology Letters, DOI: 10.1098/rsbl.2019.0405
More on these topics: