I've seen some marvellous results from digiscoping.
so with fast enough film you should be able to get something acceptable.
but when all is said and done, this is an area where digital kicks film's arse into the stone age.
you could get yourself over to birdforum.com as that's where the digiscoper expertise hangs out, but don't expect much film expertise from them, though you'll get advice about adapters and whatnot.
still, good luck, have fun and do report back