A Preliminary Report 
on Terrestial Mammals 
on SIC #15 
Introduction : 
The Pacific Ocean Biological Survey Program conducts periodic 
Southern Island surveys which include surveys of existing mammal 
populations. This paper constitutes a brief preliminary report on mammal 
observations and collections for SIC 15 . Effort was made to collect a 
series of rodents and lagomorphs from the islands in addition to taking 
notes on density, habitat preference, reproduction, food habits and behavior. 
Table #1 summarizes the species observed and the number collected from 
each island. 
SPECIES ACCOUNTS 
Polynesian Rat 
(Rattus exulans ) 
The Polynesian rat was observed and collected from three of seven 
islands visited on SIC 15 : l 4 specimens were collected from Birnie, 4 from 
Swains and 13 from Hull. According to previous reports, populations of 
R. exulans were lower on Birnie, the same on Swains, and higher on Hull 
than on previous trips. 
Rats on Birnie, which is a dry island, were found in rock piles and 
under logs. The average density was one rat per 105 square feet of ground 
area. Rock piles were utilized as nesting areas; nests were usually composed 
of straw and dried pieces of Boerhavia. Rat nests were usually found several 
inches above the ground level in rock piles, possibly because hermit crabs 
