Red-billed Leiothrix in Hawaii — Fisher and Baldwin 
51 
mules, gone from back but present on crown 
and femoral tracts, sparse on crural tract; 
feathers forming fluffy covering over entire 
body. The primaries were lined with golden- 
yellow; breast, yellow-green; back, dark yel¬ 
low-green; ventral tracts, whitish yellow- 
green; undercoverts of tail, yellow (still in 
sheaths); secondaries, black and dark green. 
The bill was dark salmon, but superficially 
gray; rictus, whitish along edge; legs, yellow¬ 
ish-tan; and claws, yellow-orange at tips. 
The weights of the young are summarized: 
AGE SIBLING A SIBLING B SIBLING C 
gm. gm. gm. 
1 day . . . 3.1 3.0 3.2 
7 days . . . 13.0 13.9 13.5 
11 days. . . 15.0 _ 15.2 
When the birds were 1 hour old, their 
movements were sluggish; the head was 
lifted to receive food, and swallowing was 
accomplished. When 24 hours old the nest¬ 
lings could squirm around; they rested on 
their abdomens. They threw back their heads 
and opened their mouths frequently. Beg¬ 
ging behavior and ejection of feces could be 
brought about by touching the nestling. 
When not active they lay curled up on their 
sides with legs and toes flexed. At 7 days of 
age they still were unable to crawl. At 11 
days one sibling left the nest when the ob¬ 
server tipped it to look inside. It escaped 
into the bushes by moving along the ground 
in short flights (3 feet). The nestlings could 
perch well, and they shifted their footholds 
to compensate for movements of the nest. 
Low-pitched alarm notes were uttered when 
they were trying to escape capture. 
FOOD 
Animal matter found in the stomachs of 
13 birds from Hawaii National Park came 
from various species of Hymenoptera, Dip- 
tera, Lepidoptera, and Mollusca. Plant ob¬ 
jects included fruits of the thimbleberry 
(Rubus rosaefolius ) and other fruits and 
stems. The proportion of animal to plant 
matter varied from all animal to all plant 
food, but the proportions usually were be¬ 
tween 40:60 and 60:40 by volume. Grit 
was typically present in the gizzard. 
Observational data on Oahu indicate that 
the birds also feed on the fruits of strawberry 
guava ( Psidium Cattleianum ), overripe pa¬ 
payas, petals of small flowers, and small new 
buds of various plants. Leiothrix has also 
been seen to capture insects which flew near 
its position, but in feeding on insects it does 
not fly out from a perch in typical flycatcher 
fashion. 
BIRD MALARIA 
Blood smears from 11 specimens of Leio¬ 
thrix from Hawaii were examined by the 
U. S. Fish and Wildlife Service. Plasmodium 
vaughani was reported from one smear made 
from a bird taken near Kipuka Puaulu in 
Hawaii National Park. 
INTERACTION WITH OTHER ANIMALS 
Although at times Leiothrix seems to be a 
noisy, aggressive bird, we found no antago¬ 
nism toward other avian species except on 
one occasion. An observer was at a nest of 
the species, and under the stress of excite¬ 
ment one of the adults drove a foraging 
Olive-green Creeper (Paroreomyza hairdi 
mana) from the nest tree. 
Except for the Hawaiian Hawk on the 
island of Hawaii, there is no evidence to 
indicate that other avian species molest Leio¬ 
thrix in any way. Elsewhere in the Hawaiian 
Islands, the only possible predators on this 
species are mammalian—the rat, the mon¬ 
goose, wild dogs and cats, and feral hogs— 
and these would exert pressure on the popu¬ 
lation by destroying eggs and young. 
REFERENCES 
Caum, Edward L. The exotic birds of Hawaii. 
Bernice P. Bishop Mus. Occas. Papers 10 (9), 
55 p., 1933. 
Henshaw, Henry W. Report of the Committee 
on the Introduction of Birds into the Hawaiian 
Islands. Hawaii. Forester and Agr. 8: 61-64, 
1911. 
