592 
ISLETS IN MAIN HAWAIIAN GROUP: Accord- 
ing to Mr. D. N. Woodside (personal commu- 
nication), rabbits were introduced to several of 
the small islets of volcanic origin (10 to 70 
acres) lying off the islands of the main Hawai- 
ian group at unrecorded dates before or about 
1915. At present only three of the islets are 
populated by rabbits: Manana ("Rabbit Is- 
land") (22° N, 158° W.), off the coast of 
Oahu; Lehua (22 Q N., 160° W.), off the coast 
of Niihau; and Molokini (21° N, 156° W.), 
situated in the channel between Maui and Ka- 
hoolawe. These tuff-cone islets are rather arid, 
suffering summer drought and occasionally miss- 
ing sufficient winter rains to alleviate the dry- 
ness. The rabbit populations are subject to vio- 
lent fluctuations, "die-offs” occurring during the 
droughts, which perhaps enables the vegetation 
to survive. There are no predators on these is- 
lets. The rabbits on Lehua and Molokini appear 
to be a mixture of domestic breeds, being of 
every colour; the Manana rabbits closely resem- 
ble the American cottontail in colour and ear 
length and it is conceivable that these rabbits 
are in fact cottontails ( Sylvilagus spp.). 
PHOENIX ISLAND (4° S., 171° W.) : A small 
coral island about 44 mi. long in the Phoenix 
group. There was an American guano company 
working here in the late 1860’s and about this 
time domestic rabbits were liberated (Bryan, 
1942). Lister (1891) found them fairly plentiful 
in 1889 and they were still fairly numerous in 
1924, but apparently were doing no damage to 
the vegetation (Bryan, 1942). A survey party, 
which in 1937 caught a number of rabbits there 
in an unsuccessful attempt to liberate them in 
the Gilbert Islands, found them in very poor 
condition, squatting and allowing themselves to 
be caught after running about a hundred yards. 
There is no fresh water on the island (Maude 
and Maude, 1952). 
PHILLIP ISLAND: A small island about half a 
mile long of decomposed basalt rising to 900 
ft., lying off Norfolk Island (29° S., 168° E.), 
originally covered with trees and thick vegeta- 
tion. Pigs which were introduced at an early 
date destroyed much of the undergrowth and 
rooted up the soil, starting erosion. Rabbits were 
introduced subsequently (Laing, 1915) and the 
island thronged with them in 1865 and their 
principal food seemed to be the bark of trees 
PACIFIC SCIENCE, Vol. XV, October 1961 
(Brenchley, 1873). By 1912 the island was fast 
becoming a complete desert; there was practi- 
cally no soil, only a few isolated trees; hardly a 
seedling was to be seen and the only grass was 
in clefts in the rock near the beach (Laing, 
1915). Rabbits were still present in 1943 and a 
single tree was conspicuous in its isolation (Mr. 
I. L. Baumgart, personal communication). 
The present situation on Phillip Island is in- 
dicated in a recent letter to Dr. K. Wodzicki 
from Mr. B. a’B Marsh, Agricultural Officer, 
Norfolk Island. 
Mr. Marsh made a hurried visit to the island 
on 4 March 1961 and saw rabbit scratchings, 
droppings, and a few burrows, the last being 
under the roots of Lagunaria Patersonii and 
another unidentified tree. The visit, being in 
the middle of the day, was not well timed for 
seeing rabbits, but, as a very rough guess, Mr. 
Marsh thought there might be between two and 
four dozen rabbits on the island. The animals 
had been eating the leaves of Lagunaria which 
seemed their main food. 
Vegetation consists of six Norfolk Island 
pines ( Araucaria excelsa) , several dozen 
Lagunaria trees, a few unidentified trees with 
large shiny leaves, a reed known locally as 
Mo-oo and a few grasses and weeds. The reed 
grows in a few areas of 1/10 to Vi acre, usually 
in flat areas where there is enough soil to retain 
water, but over perhaps 80 per cent of the is- 
land there is no vegetation or soil. Rabbits do 
not eat the reed or the unidentified trees; the 
latter are the only trees that appear healthy. 
All trees have their roots exposed to a depth 
of 1-6 ft.; the pine trees are not actively grow- 
ing but are setting seeds; the leaves of the 
Lagunaria are confined to the main branches so 
that the trees look as though recovering from 
a fire. 
The topography of the island is steep with 
V-shaped erosion gullies at frequent intervals; 
run-off of water is extremely rapid and com- 
plete and carries extraordinary quantities of 
solid material. The effective rainfall is probably 
about 5 to 10 in. per annum overall, but the 
steeper parts retain practically no rain; the is- 
land was quite dry only two days after heavy 
rain. All soil has gone except from a few flat 
areas and screes, and removal of rabbits will 
