Animal advocates are warning residents about the dangers of feeding bread to ducks, geese or swans.

Hospital supervisor at Evelyn Alexander Wildlife Center in Hampton Bays, Adrienne Gillespie, says what some think is a simple act of kindness can actually lead to a condition called "angel wing."

"It causes nutritional issues, basically throws off their vitamins and they develop these deficiencies in the bones in their wings," Gillespie says. "And it causes the wing to be deformed."

Gillespie says that means the birds cannot fly or survive in the wild, eventually leading many of them to be humanely euthanized.

Experts say those who do want to feed birds in the wild a snack should use cracked corn or items that can be bought at a feed store.

"It's a healthier option and you can spread it out," Gillespie says. "It's definitely a better alternative than bread."

Gillespie says in her time at the Evelyn Alexander Wildlife Center she has seen over 20 cases of angel wing.