CHRISTMAS ISLAND. 



ZOOLOGY- 



MAMMALIA. 



By C. ^y. Andeews, B.Sc, F.Z.S. 



As might be expected in an oceanic island, the mammals are 

 both few in number and of small size. The collections brought 

 back by the officers of H.M.8. "Flying Fish" and by Mr. Lister 

 included two species of rat {Mus macleari and M. nativitatis), 

 a large fruit-bat {Pteropus natalis), and a shrew {Crocidura 

 fuliginosa, var. trichura) ; a small insectivorous bat was seen, 

 but no specimens were obtained. Unfortunately no additions 

 have been made to this list, but further information as to the 

 habits and other points of interest have been obtained, and the 

 small bat is now described for the first time. 



The conditions of life arc apparently extremely favourable, food 

 being always abundant, and the hawk and owl, which are the only 

 possible enemies, feeding mainly on birds and insects. The con- 

 sequence of this is that all the species of mammals are extremely 

 common, and the individuals are always exceedingly fat. Perhaps 

 Mus nativitatis, the bull-dog rat as the Cocos Islanders have 

 named it, is the least numerous, probably because of some 

 competition with the much more active and versatile M. macleari, 

 but most specimens of If. nativitatis have a layer of fat fi'om half 

 to three-quarters of an inch thick over most of the dorsal surface 

 of the body. The fruit-bats are likewise invariably in remarkably 

 good condition, and considerable quantities of oil can be obtained 

 from them. 



With the exception of the small bat, all the species have been 

 described by Mr. 0. Thomas in two papers^ dealing with the 

 collections made by the officers of H.M.8. "Flying Fish" and 

 by Mr. J. J. Lister. His descriptions will be here reprinted, with 

 such additions as the increased material renders possible and with 

 some notes on the habits of the sovei'al species. 



1 P.Z.S., 1887, pp. 511-614, pis. ili, xlii; and 1888, pp. 532-534. 



