Guadalupe storm petrel

The Guadalupe storm petrel (Hydrobates macrodactylus) is a small seabird of the storm petrel family Hydrobatidae. It bred only on Guadalupe Island off Baja California, Mexico, and presumably ranged throughout the region. It has been assessed as Critically Endangered or possibly extinct.

This species was almost indistinguishable from its relative, Leach's storm petrel. In the field, they could not be told apart except by their annual rhythm. In the hand, the Guadalupe storm petrel could be distinguished by slightly larger size and the paler underwing coverts. There is no evidence for sexual dimorphism in this species.