This is a guide to altricial passerines. It has an explanation of variables used for aging birds and an explanation of methodology employed, and provides information obtained while recording the early aging of the Dusky Flycatcher, the Carolina...
Endangered species; Birds; Birds of prey; Captive breeding; Reintroduction; Raptors;
1976, (41 FR 187). Long recognized as a vanishing species (Cooper 1890, Koford 1953, Wilbur 1978), the California condor remains one ofthe world’s rarest and most imperiled vertebrate species. Despite intensive conservation...