Droppings of the kit fox show an abundance of bones of small mammals of
kangaroo rat size, among them those of _spectabilis_.

Bobcats (_Lynx baileyi_) and coyotes (_Canis mearnsi_) probably are a
prejudicial factor. Skunks may sometimes be able to surprise the
kangaroo rats, but probably not often. The western horned owl (_Bubo
virginianus pallescens_), the barn owl (_Tyto alba pratincola_), and
perhaps others may well be among the most feared enemies, but no special
investigation of owl pellets on the reserve has been possible. In 592
barn-owl pellets from California were found remains of 230 kangaroo
rats, only one other rodent being represented by a larger number
(McAtee, 1921, 258).

Much more information on enemies is needed. The relatively low rate of
reproduction (see p. 18) indicates comparative freedom from inimical
factors.


PARASITES.

_Dipodomys s. spectabilis_ is regularly infested with a species of flea,
_Ctenophthalmus_ sp. Seldom or never is a specimen taken in reasonably
fresh condition without some of these parasites present on its body,
though of course they desert the body of the host after it becomes cold,
and hence dead specimens left too long may be free from them. The den
conditions are ideal for the breeding of this parasite, because of the
great quantities of fine, dusty, organic refuse littering the tunnels
and furnishing food and refuge for the larvæ. As demonstrated to us by
F. C. Bishopp, of the Bureau of Entomology, a handful of this refuse
taken from the floor of a burrow within arm's length of the entrance is