I can't see why this isn't just a juvenile Barn Swallow. Also, bear in mind that swallow are passerines and swifts are non-passerine and as such are not even closely related. Bird hybrids in the wild tend to be between closely related species. Such a hybrid pair (between individuals in two different orders) is probably unprecedented, at least within birds. Author: kkchang168 Time: 20/06/2017 15:17
Thanks very much for such a clear explaination.
Welcome to HKBWS Forum 香港觀鳥會討論區 (http://hkbws.org.hk/BBS/)