° '1919 J MacCaughey, The Hawaiian Elepaio. 23 



Family. — The Old World Flycatchers, Muscicapidoe, comprising 

 about 60 genera and some 400 species, are represented in the 

 Hawaiian avifauna by Chasiempis only. The family is common in 

 Ethiopian, Indian, and Australian regions; several are Palsearctic, 

 and 4 or 5 reach Europe. The family is fairly abundant in the 

 islands of the South Pacific, but in the central North Pacific is 

 confined to the Hawaiian group. 



Genus. — The genus Chasiempis, comprising all the Hawaiian 

 species, was established by Cabanis in 1847 (Archiv fur Natur- 

 geschichte 1847:207). The members are true Flycatchers, with 

 broad soft beaks, the gape of which is beset with long, strong, 

 spreading bristles. The tarsus is characteristically long and 

 slender. The first primary is about one-half as long as the second; 

 the second is about one-fourth inch shorter than the third; the 

 fourth, fifth, and sixth are equal and longest. The tail is about as 

 long as the wing; the rectrices are pointed. The sexes are similar 

 in size and plumage, but the juvenile plumages differ in many 

 striking particulars from those of the adult birds. 



Key to adult birds. — The specific status of the Elepaios for many 

 decades was a subject of great perplexity to ornithologists, and 

 led to extended discussions and controversies. The careful studies 

 of such workers as Rothschild, Perkins, Wilson, and Bryan, have 

 reduced the chaotic synonymy to order and conclusively demon- 

 strated that there are three valid species, — one each for the islands 

 of Kauai, Oahu, and Hawaii. 



Much perplexity and confusion arose from the numerous inter- 

 grading plumage changes through which all the species pass before 

 they reach maturity. The differences between the mature and 

 juvenile birds have misled ornithologists to describe them under 

 different names, so that as many as six or more species were recog- 

 nized by some investigators, while others have referred all to a 

 single species. 



The adults of all three species are characterized by wing-coverts 

 spotted with white; black or white or both on the throat; tail- 

 coverts white; lower mandible dark. The adults of all species 

 have the rump white; the young have the rump tawny. They 

 not infrequently breed in quite immature plumages; there are 

 numerous records of pairs, one white-rumped, the other rufous- 



