Residents are being urged not to feed bread to birds at local parks.
Reader Janice Dyson took the above picture of a swan - which has a deformity called ‘angel wing’ - at Poolsbrook County Park in Chesterfield.
‘Angel wing’ is a condition commonly found in swans, ducks, geese and other waterfowl.
It causes one or both wings to unnaturally twist outward, rather than lying flat against their body - leaving them unable to fly away from predators and potentially resulting in their death.
Experts say the syndrome is caused by a nutritional deficiency in vitamins and minerals combined with a high level of carbohydrates and sugars.
While a number of factors are involved, human-fed bread is one of the probable causes.
The RSPCA and the Canal and River Trust urge people not to feed bread to wildfowl and instead give them healthier food like sweetcorn, rice, oats, seeds, chopped lettuce and defrosted frozen peas.