42 HAWAIIAN BIRDS. 



across the forehead a narrow, and above the eyes a conspicuous orange- 

 yellow superciliary stripe. Quills deep brown, outer webs edged with 

 greenish yellow. Chin, throat and upper breast bright orange-yellow; 

 abdomen yellow. (Rothsch.). 



Heterorhynchus afiSnis Rothschild. 



Found only upon Maui where it is generally confined to tne 

 more elevated forest. Mr. Perkins states that this bird has two 

 songs, one of which is identical with that of the Hawaii species, 

 while the other is much like that of the house finch introduced 

 from California. He finds that the food of the Maui species, like 

 that of the form on the island of Hawaii, consists mainly of in- 

 sects, "but the birds are quieter and less vigorous in their move- 

 ments." He records the fact also that this species sucks honey. 



Description. — Adult male. Top of head bright gamboge-yellow, passing 

 into yellowish-green on the nape and hind neck, the green being rather 

 abruptly terminated by the grayish olive-green of the back, brighter and 

 greener on the upper tail-coverts. Quills and rectrices deep brown, 

 bordered with bright olive green. Lores black, connected by a black band 

 across the forehead. A tiny black chin spot. Throat bright yellow, pass- 

 ing into sulphur-yellow on the abdomen and pale yellow on the under 

 tail-coverts. Sides of body tinged with greenish-olive. (Rothsch.). 

 Female much duller. 



Heterorhynchus hanapepe (Wilson). Nukupuu. 



The nukupuu inhabits the forests of Kauai, from an elevation 

 of from 2,000 to 3,000 feet, where it seems to be decidedly rare. 

 Like its congeners, whose general habits it shares, the nukupuu 

 lives chiefly upon insects. The fact that all of the several species 

 of this curious genus live principally upon insects is attested by 

 all who have observed their habits. Indeed the result of these ob- 

 servations might have been predicted from a study of the birds' 

 structure. Long centuries of insect hunting, under the peculiar 

 conditions found in the Hawaiian forest, have impressed upon 

 the birds of this genus the stamp of extreme specialization. Their 

 modification has been all in one direction, and their equipment is 

 that of the highly specialized insect hunter. 



