This is caused by the Papillomavirus, a DNA virus that is more normally associated with parrots and macaws. For those with an abnormal fascination with the virus, more details can be found in this paper.
This Chaffinch is one of the most extreme cases we've ever seen, and was caught on 15 March near Ripon. The extent of the growths is incredible, and the bird obviously has difficulty walking and presumably feeding normally, as it has very abnormal claw growth on its feet. The virus has been noted in the Chaffinch population at the site for several years, though the majority of birds coming to the feeders in the winter still have 'clean' legs. One adult male, though, that had regularly been caught at the site had lost one foot due to the virus.
Thanks (I think) to Yvonne Elvin for the photos and to Jill Warwick for passing them on.
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ReplyDeleteNice! Suprised it has lived as long as it has!
ReplyDeleteAre Zebra finches also afflicted? I had a similar issue with my finches years ago, and no clue at all what was causing it.
ReplyDeleteHope the ringer washed her hands before lunch!
ReplyDeletethank you for pointing me towards a very interesting and detailed paper on the subject. The disease is farly common in chaffinches locally (Isle of Wight)and I have a file of pictures of developing papilloma pathology. One thing that fascinates me particularly is that when caught, despite disease as severe as in the blog picture, the birds are always in good condition with full weights and breeding plumage. I imagine that inevitably their lifespan is shortened but as far as I have seen there is no long decline in condition.
ReplyDeleteIsn't it dangerous to take it over? I think papillomas are very contagious.
ReplyDeleteWe see this condition more at sites that have domestic chickens around, and think the wild Chaffinches may pick the virus up via the fowl. Like Daphne says, the birds do seem to be in otherwise excellent health.
ReplyDeleteI've just had a little read up about it all as it is now affecting a site I go to a lot (Warnham Nature Reserve, Horsham) and there is no known cause apart from it generally seems to be where large populations of Chaffinch's feed or gather.
DeleteHi Daphne,
ReplyDeleteWe have a website about papillomaviruses http://pave.niaid.nih.gov
and are in the process of establishing an image library. Would you consider sharing some of your images? Please contact pavewarts@mail.nih.gov
Thanks
I live in Northern Italy and have several chaffinches visiting the garden. One male has a very similar appearance to the photos here. It seems in reasonable health but clearly has difficulty hopping.
ReplyDeleteAt last I know what's affecting a male chaffinch in my garden in Norwich! He seems to manage Ok for now.
ReplyDeleteI have a male and female chaffinch in my garden, also in Norfolk. Is there anyone recorded numbers of birds affected?
ReplyDeleteWe have a male and female chaffinch suffering from the same condition here in our Norwich garden. The female seems to be in pain with her right foot from the scaly growths as she tries to land.
ReplyDelete