New video analysis reveals the furry thieves are looting up to half the seed put out in feeders, leaving gardeners and birds short-changed

Daylight robbery worth millions of pounds is taking place in gardens across the country with grey squirrels raiding bird feeders on a huge scale, new research has revealed.



The crimes were caught on video camera by scientists, who said grey squirrels are also known to raid birds’ nests for eggs and chicks. So people putting out food for birds are inadvertently supporting a species that harms them.

Over 40% of households across the UK put out bird feed, totalling about 150,000 tonnes a year and costing £210m. But the new analysis, based on video recordings of more than 33,000 visits to bird feeders, showed much of the food is being snaffled by squirrels.

Grey squirrels, though loved by some people, are an invasive alien species that has driven the native red squirrel out of much of the UK and they are also a pest in orchards and commercial forests. However, using feeders that are enclosed by a cage can help stop the squirrels getting their free lunches.

“Anybody who feeds birds knows that there is a good chance that squirrels will come in to your feeders,” said Prof Mark Fellowes, at the University of Reading, who led the new work published in the journal Landscape and Urban Planning. “The question is how much is going to the target species – the birds?”

To find out, the researchers placed automated video cameras in suburban gardens around Reading and found that birds would not go near a feeder when a squirrel was present. Furthermore, when squirrels were frequent visitors, they deterred birds even when not actually on the feeder.

“Squirrels don’t just simply push birds off feeders, those birds change their behaviour,” said Hugh Hanmer, at the British Trust for Ornithology and also part of the research team. Overall, squirrels were responsible for almost half the recorded visits to feeders, a frequency that surprised the scientists. As larger animals, squirrels are likely to eat more than half the food.

Feeders that incorporate a protective cage were also watched during the study and these cut squirrel visits to peanut feeders by half. But, said Prof Fellowes, the rodents are accomplished burglars and were often able to take some nuts.

In contrast, caged seed feeders were rarely visited by squirrels, who much prefer the nuts. However, caged feeders also reduced the number of visits by birds, probably because the birds feel less able to escape a predator when inside the cage.

Squirrels in the garden: your deterrents Read more

Another way to foil the squirrels is putting out food that only birds like, such as the niger seeds loved by goldfinches, or even greasing the pole supporting standalone bird feeders.

The best solution, said Prof Fellowes, are feeders that have a spring-loaded mechanism which closes the feeder when a relatively heavy animal, such as a squirrel steps on it, though these are more expensive.

Robert Middleditch, at the charity SongBird Survival, said: “These findings greatly add to our understanding of the significant economic and environmental damage that non-native grey squirrels cause. The good news is that by using simple solutions we can help make sure that the food goes to our garden birds, and it may even help us save money [on feed] in the process.”