WOODPECKERS. 



427 



the liiglily-cleveloped nuchal crests in many tropical species. A noteworthy structural 

 speciulizutiou iu several forms, otherwise not intimately related, is ihe abortion of the 

 first toe, so that only one hind toe remains — the fourth. Nevertheless, there arc sev- 

 eral i)retty well defined groups, or super-genera, under which the numerous sjiecies may 

 be advantageously classified. 



Most woodpeckers have the nostrils concealed by tufts of bristly feathers directed 

 forward. In many museum sijecimeus from the tropics these may have disajipeared, 

 as the putrefaction which in those countries rapidly sets in first affects the feathers 

 around the bill. But a small grou]) of species, about e(|iially numerous in the tropical 









Fio. 214. — Picua viridia, green woodpecker, yalBe. 



regions of both hemispheres, have no bristles where the bill joins the forehead, and 

 tlie nostrils are consequently fully e.\j)osed. Xotewortliy among these forms is the 

 South American genus Celeiis, the members of which have a very long occipital crest. 

 Some of the Indian species have only three toes, for instance the genus Tii/a. The 

 absence or presence of the nasnl bristles seems, however, to be of little account, since 

 yesoceleus fernandiiK^, which is confined to the island of Cuba, has the nostrils entirely 

 nude, tliough a]>parently closely related to the following group. 



Our flicker {Colaptes aiirattis) and its many allies belong to another group, which 

 arc distinguished by having a less tyjiical weilgo-sha]ped woodpecker bill, the angles 

 being more rounded, and the whole bill slightly arched. In reganl to the remarkable 



