On Dec. 23 I took a series of photos of a Downy Woodpecker which happened to have a tree frog clinging to its back. There are 4 photos in the original posted series (on Flickr) and an additional close up of the frog in a fifth photo located in the comment section below the other photos.
At first, there was some discussion in the comments as to what this was on the back of the bird. Some folks thought it could be a wound of some sort or even brush material stuck to the back via tree sap. But I'm now personally convinced the rider is a tree frog. Please take a look at the photos if you are interested! Thanks for looking!
http://www.flickr.com/photos/dsdavenport/4214866019/
Dennis S Davenport
Great pic. Interesting implications on biogeography. Why hop on the ground when you can take a free flight.
i keep frogs as a hobby and i've never heard of anything like that at all.
though i can see one advantage to the frog in that the bird is warm blooded.
the frog won't be stuck as some people have suggested they are moist not sticky. it has probably found a nice warm spot which is helping it digest it's last meal, no doubt it is currently enduring a cold spell and any source of heat will be appreciated.
conversely the fact that being on the bird is keeping it wamer than it normally would be other wise may well cause it to starve to death if it can't find a source of readily available food once it's used up it's reserves.