About 20 ducks died at a city park in Windsor, Ont. after eating garbage and junk food brought to the area by visitors, according to naturalists who've studied the mass death late last year.

The bodies of the ducks were found in late September at the Captain John Wilson Park, where residents say they have seen people regularly dumping garbage near the pond.

Naturalists were initially baffled by the deaths. Necropsies conducted on the birds revealed they died of starvation and malnutrition. It was an odd finding considering the ample amount of natural food in the area, according to Tom Preney, a naturalist at the City of Windsor's Ojibway Nature Centre.

Eating the garbage people dumped at the park is believed to be the primary cause of death, but that may not be the only reason, he told CBC News.

"It turns out these ducks are fed junk food, so they are getting fed bread and other things, which is not healthy for them," Preney said. "So, they are not able to digest these foods that have high carbohydrates and they are not getting the nutrition that they need and they are starving to death essentially."

Unusual deaths

Duck Carcass

Duck carcasses littered the shore of a pond at Captain John Wilson Park after the ducks died of malnourishment. (CBC News)

The unusual number of dead ducks found at the park led the experts to send the animals to the University of Guelph to be analyzed.

There were initial fears the mass death could have been caused by a virus called avian botulism, which is a common waterfowl ailment particularly common in North America.

"It is alarming when you see such a large die-off of ducks and usually you think it is something environmental, but in this case it seems that it wasn't environmental," Preney said. "It was because of human impact."

The problem of malnourished ducks is not specific to Captain John Wilson Park.

Wings Wildlife Rehabilitation Centre regularly deals with birds with similar health conditions, said the centre's president Nancy Phillips.

She and her staff regularly work with malnourished ducks from throughout the city and Essex County, but most of those incidents involve birds suffering from illnesses like botulism. The centre can receive about five or six birds a day during the winter months of January and February.

"When the heat is extreme ... there are a lot of pesticides in the water that they might get into," Phillips said. "Basically, when we see them, they become lethargic and weak. Some of them stagger and can't stand on their legs."

Dangerous feeding

Don't Feed Sign

City of Windso staff will be delivering pamphlets that outline the dangers of feeding birds. (CBC News)

Recognizing ducks can suffer from eating non-nutritious food provided by people, Phillips urges people to stop feeding the birds.

Bread is one of the worst food to feed a duck, Phillips said. Bread is filling, but provides very little in terms of nutrition.

"They don't get any good vitamins or anything, so it is really a waste of time feeding [them] that, other than it will fill them for that minute," she said.

Ducks are better off fending for themselves, according to Jeremy Hatt, a member of the Field Naturalist Club. He too recognizes the sometimes harmful results of feeding the birds bread.

"Absolutely, don't feed them bread. Bread is the worst," he said. "Ducks are living in their natural element and they will find food and if they don't they will be moving to a new food source, so it is not really a necessity at all"

Phil Roberts, executive director of parks at the City of Windsor, says the city wiill be launching an information blitz in the neighbhourhod near Captain John Wilson Park.

Staff will be delivering pamphlets that outline the dangers of feeding birds.

With files from Meg Roberts