Red-billed Leiothrix in Hawaii — Fisher and Baldwin 
47 
averages of precipitation in its observed 
range on Oahu vary from 30 to 200 inches. 
On Hawaii the species is rare or absent in 
areas having less than 20 inches a year; 
this is true in the leeward districts. In the 
Kau district, where rainfall is 20 inches or 
less in much of the lowland, Leiothrix is rare 
below 3,000 feet and absent below 2,500 
feet. On Maui the annual rainfall in parts 
of the range of the species is 350 inches. 
Presence or absence of surface water may 
be a significant factor. The species has often 
been observed bathing in water up to 2 inches 
in depth. Further, the birds are most fre¬ 
quently observed within a few hundred yards 
of such water. We have on several occasions 
noted birds drinking rain water caught in 
basins formed by the large fallen leaves of 
the ti plant ( Cordyline terminalis ) and the 
kamani tree ( Terminalia Catappa ). 
HABITAT IN THE HAWAIIAN ISLANDS 
A cover of dense vegetation near the 
ground is the major characteristic of the habi¬ 
tat of Leiothrix. Without exception the birds 
are found in areas having such a growth. It 
seems immaterial whether or not a canopy is 
formed above this undergrowth, as long as 
there is a thicket 10 to 15 feet in depth. We 
have never found this species feeding, nest¬ 
ing, or even remaining long in the large 
plantings of imported ironwood ( Casuarina) 
or exotic Eucalyptus; there is rarely any 
ground growth in such places. The birds are 
frequently found in guava ( Psidium Gua- 
java) thickets not having a high canopy. 
On Oahu the species is most abundant in 
the dense understory of forested and partly 
forested areas on the floors and steep slopes 
of the valleys. Usually there is in this habitat 
a stream, a small pond, or some temporary 
catch basins (fallen leaves, concavities in 
rocks) to hold rain water. On the extremely 
steep slopes of Manoa Valley, Oahu, at 1,100 
feet where the rainfall is between 100 and 
150 inches annually is a "typical” habitat. 
Here are scattered ohia lehua ( Metrosideros 
collina var. polymorpha) trees up to 12 and 
15 feet in height, interspersed with koa 
(Acacia Koa ) trees up to 30 feet high and 
with kukui nut ( Aleurites moluccana) trees. 
These three kinds of trees form in many 
places a loose, open canopy. In certain areas 
the kukui trees form a dense canopy. The 
understory consists of ti plants ( Cordyline 
terminalis) up to 8 feet in height, a few 
Gardenia Remyi trees, and an occasional 
white hibiscus [Hibiscus Arnottianus) . The 
lowest-growing vegetation is made up chiefly 
of palm foxtail [Setaria palmifolia) and oi 
shrubs [Stachytarpheta cayennensis) . This 
growth is in many places so dense that it is 
difficult to penetrate. A further factor in 
creating an almost impenetrable thicket is 
the presence near the ground of many fallen 
branches. Also, in a few places the inter¬ 
twining branches of the hau tree [Hibiscus 
tiliaceus) add to the maze (Fig. 1). 
Fig. 1 . Thicket formed by branches of the hau 
tree (Hibiscus tiliaceus ) in Nuuanu Valley, Oahu, 
at 1,000 feet elevation. 
On Hawaii this babbler is most abundant 
in forests from 1,000 to 5,000 feet elevation 
and with 40 or more inches of rain each year. 
Forests with a variety of habitats, such as koa 
forest partly modified by cattle grazing and 
with thimbleberries [Rubus rosaefolius) and 
other fruiting plants, harbor large numbers 
of the species. The density reaches 80 to 
