70 



AVIFAUNA OF LAYS AN, ETC. 



adult bird, but the white colour less pure and less in extent. Iris brown; bill deep 

 blackish brown, base of lower mandible light-coloured. 



Nestling. Above similar to the young just described and showing the rufous colour on the 

 rump, but some blackish tips of the feathers produce a somewhat spotted appearance. 

 Feathers below white, more brownish on the breast, and mostly slightly bordered with 

 blackish, producing- a somewhat spotted appearance. 



The total length was measured by Palmer to be as great as 5 J in the flesh, while in the skins 

 it is only about 5 to 5£ inches. Wing 2 to 2'8, tail 25 to 27, tarsus 0-9, culmen ()• L5. 



] cannot see any remarkable difference between males and females, but perhaps the females 

 have a slightly shorter wing as a rule. 



Hob. Oahu. 



The observations of Palmer and his assistant Wolstenholme leave no doubt that the white- 

 rumped and the rufous birds arc old and young of the same species, and, moreover, Palmer has 

 sent two specimens which distinctly show a resemblance between these two different plumages. 

 On the other hand, Palmer and his assistant have also seen rufous-rumped birds on the 

 nest and feeding their young, although less frequently than white-rumped birds. From these 

 observations it is obvious that the white rump and white wing-spots (i. e. the " adult plumage ") 

 are not gained in the first year and that these birds, like the Ch. saudivichensis of Hawaii and 

 probably also Ch. sclaterl of Kauai, sometimes breed before they have gained the adult 

 plumage, as is sometimes the case with other birds elsewhere, especially Bapaces. Palmer, 

 in his diary of April 1803, says : — " I saw a pair, one bird rufous-rumped and the other 

 white-rumped, build a nest. I think they change their rufous plumage into the white in the 

 second year, if not much later." 



Chasiempis gayi, Wils., is one of the commonest, if not the commonest, of all the small 

 native birds on Oahu. It is an inhabitant of forest and is generally seen flitting about from 

 tree to tree, very often taking insects on the wing. They arc frequently seen with drooping 

 wings and the tail elevated almost vertically. Like the Ply catchers of Hawaii and Kauai, these 

 birds are very tame and often come close up to the observer ; they also eagerly follow the call- 

 note when properly imitated by men. The call-note is a rather shrill forced note and sounds 

 like " J?4p~pd-k6~o." The food consists of insects, which are mostly captured on the wing, 

 but flightless insects are also found in the stomachs, such as caterpillars, grubs, and spiders. 



Our early spring months, March and April, seem to be their breeding-time. A number 

 of nests were found in March and April. 



The nests were found on young, tall, broad-leaved trees, generally at heights of from 10 

 to 30 feet, placed in a kind of fork among the thin branches. 



The nest is deep and cup-shaped, built of very fine roots and moss and lined with root s 

 and fine haulms, outside beautifully ornamented with light-coloured lichens. The cup is nearly 

 or fully 1^ inch deep, and measures about 2 inches across, the walls being nearly f of an inch 

 thick. The egg is ovate and measures 125 X I'll inch: it is white, covered with small 

 spots and blotches of a brownish red (brick-red) ; the white ground-colour is not at all shaded 

 with, bluish or greenish but is, if anything, yellowish. The egg resembles much that of a 

 Common Titmouse. 



