A deadly disease is having a devastating impact on bird populations, an ornithological enthusiast was warned.
Greenfinch populations in Sussex are thought to have dropped by up to a third and chaffinch populations by a fifth, according to a study by the Garden Bird Health Initiative.
The garden birds are suffering from trichomonosis, a parasite which infects the digestive system of mostly finches, doves and pigeons.
It causes lesions in the throat which makes it hard for the bird to swallow food leading it to die of starvation.
Affected birds appear “puffed-up” with fluffed-up plumage and are generally lethargic.
Peter Calladine, member of the Royal Society for the Protection of Birds (RSPB) and Royal Ornithological Society, said: “It’s very bad news. It is very widespread and causing huge losses to the bird population in Sussex. The numbers have fallen terribly. We are talking thousands.
“Greenfinches seem to be the most affected. The disease is very distinctive. They get all puffed up and it’s quite obvious they’re dying.”