We have now noticed three different Chaffinches with fungus on the legs, see photo. The following answer was given on the RSPB site to a similar queries
Birds can suffer from a number of skin conditions that affect the feet. In a chaffinch, it is overwhelmingly most likely to be chaffinch viral papilloma. This virus is specific to chaffinches only. Although it looks unsightly and certainly is a great nuisance and irritation to the bird concerned, it is rarely the cause of demise for the bird. The papilloma has low contageousness, and birds need a close contact with each other for the infection to be passed on. This is probably why it is normally seen in clusters. It is believed that a bird will need a cut or a scratch on its foot for the disease agent to enter and infect it. There is no cure for this kind of skin infections in wild birds, and the only thing we can do to help is to make sure that there are no sharp bits in the feeders that could risk a bird cutting its foot as it is looking for food.
We also found another raided bees nest see photos, and no sign of what the raider took.
Bob and Bri