yellow-bellied sapsucker (female woodpecker)

Although most non-birders believe that the Yellow-bellied Sapsucker is a fictitious bird created just for the humorous name, in fact it is a widespread species of small woodpecker. Its habit of making shallow holes in trees to get sap is exploited by other bird species, and the sapsucker can be considered a "keystone" species, one whose existence is vital for the maintenance of a community.