British junk food lovers are having an unhealthy effect on the country's pigeons, which are becoming obese by feasting on litter leftovers.
The charity Keep Britain Tidy says people who do not throw their uneaten junk food away are causing the problem.
Chief executive Alan Woods said the birds were now "supersized" and dependent on people rather than nature for their food.
The abundance of food on offer was also causing a population explosion of pigeons in Britain, which are considered a health hazard and a nuisance, he said.
"Seven out of the 10 bits of litter we find on our pavements and roads are food related. And with all this trash to choose from, the pigeon, rat, fox and gull population has spiraled," Woods said.
The litter problem was worse during summer because the warm weather meant more people ate outdoors.
Summer also coincides with the peak breeding season for pigeons in June and July.
Woods said if the problem continued, local councils would be forced to cull thousands of pigeons to keep numbers under control.