Where are you located? If you are in a place where there is bird flu, then be careful. But if you aren't in certain parts of China or SE Asia, then you won't get bird flu from bird feathers. The flu does not spontaniously generate on bird feathers.
It seems that almost all flu viruses begin in China or SE Asia, then travel west to Europe (an to NZ and Australia), then over to North America, then down to South America. Bird flu is dangerous because it is a strain of flu that people have now resistance to.
The current flu is genetically related to the flu of 1918, the one that killed millions. It killed millions because no one had resistance, not because it was a special kind of bug.
While I wouldn't worry about bird flu on pigeon feathers (unless you are in China or SE Asia). Birds can carry diseases. However, unless you are pulling the feathers off the birds, that is, if you don't come in direct contact with the birds, if you are picking them off the ground after the bird is done with them, then don't sweat it.
We all seem to be worrying about too many things that are not dangerous. This is one of them.