New signs, installed by Geese Peace, line busy areas along the River Avon
For many, feeding the ducks is a key part of any trip to the park.
However, visitors are being warned not to feed white bread to ducks and swans as it could kill them.
In Stratford-upon-Avon, signs now line the river around the Royal Shakespeare Theatre. They warn that white bread causes harm to waterfowl.
Campaigners explain that white bread causes their wings to develop too quickly and can lead to a disease called Angel Wing.
Maureen Beckett from a group called Geese Peace told BBC Coventry & Warwickshire they have put signs up warning you not to feed the Swans.
Visitors are encouraged to use appropriate duck food
She said: "The plaques say don't feed the geese, as they can get aggressive, ducks and swans can be fed but not white bread."
Ms Beckett adds: "Ducks and swans normally eat leaves, seeds and aquatic plants and if you feed them white bread it causes their wings to grow too quickly, it develops before the rest of their body so the wings droop and stick out so that bird can never fly.
"It looks as if it's been in a fight but it hasn't, it's a disease that's purely from being fed white bread."
If waterfowl eat white bread, containing too much protein and too little vitamin E, one or both wings can develop to turn outwards and the bird is then unable to fly.
As Ms Beckett explains, the prognosis is bad for wildfowl with Angel Wing: "It's kinder to put them down... that bird doesn't stand a chance because can never fly away from its predators."
Work is ongoing to control the Stratford goose population
However, Geese Peace are not suggesting a ban on feeding the ducks: "Brown bread is nowhere near as bad. Brown bread isn't perfect but it won't do them the harm that white bread does."
Special wheat disks for feeding the ducks and swans can also be purchased from some of the shops in Stratford-upon-Avon town centre.
The advisory plaques were added to the popular Avon riverside walks in late summer 2010.