Feral Rabbits on Pacific Islands — WATSON 
593 
not now alter the island except in a very minor 
way. 
In March 1953 myxomatosis was introduced, 
but further introductions were abandoned due 
to the difficulty of landing. It is now unlikely 
that any further eradication work will be at- 
tempted. 
DISCUSSION 
These islands provide an interesting contrast. 
On Phoenix Island, almost on the equator, con- 
ditions must be only just within the level of 
tolerance for the rabbit species, and factors other 
than food presumably hold the population down 
to a level where it does not seriously affect the 
vegetation. Rabbits have been on Phillip Island 
for nearly a hundred years and must have 
reached a state of equilibrium with the vegeta- 
tion, most of which has been destroyed, but 
some plant species must survive that are both 
resistant to rabbit grazing and yet sufficiently 
palatable to support the existing rabbit popula- 
tion. On Lisianski Island no such equilibrium 
was reached, and it was thought that rabbits 
would similarly have gone from Laysan Island 
had they not been exterminated (Wetmore, 
1925). Presumably the rate of increase of the 
rabbits quickly produced a large population, and 
the vegetation was destroyed to such an extent 
that it was unable to recover in time to main- 
tain even a greatly reduced number of rabbits. 
Manana, Lehua, and Molokini islets are all 
subject to droughts during which the rabbit 
populations are drastically reduced and presum- 
ably the vegetation can recover sufficiently to 
survive. 
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