HOWELL — FOSSOEIAL MAMMALS 
21 
It seems to be the accepted theory that most of the surface traveling 
indulged in by gophers is undertaken by old males in search of mates. 
However, while the males will undoubtedly seek out the females, either 
below or above ground, by far the majority of proven cases of emigra- 
tion of which I know have consisted either of females or of half grown 
animals. The old males, being larger (in many forms) and better 
fitted to cope with adverse conditions, such as hard digging through 
the drying soil for a failing supply of food, are probably more prone 
to remain in one spot than are the smaller , weaker individuals. At 
any rate, but few pocket gophers elect to live in bone-dry ground. It 
is true that they often make short excursions into it, but in almost 
all cases the main runways are in soil with some indications of sub- 
surface moisture. During the old days before the advent of the white 
man into the ranges of many of the lowland gophers in California, con- 
ditions entirely propitious for the presence of these animals occurred 
in somewhat restricted, and often scattered, areas, as small stretches 
of grass along the upper washes, or around the border of a cienaga. 
These spots were frequently separated from each other, sometimes by 
considerable distances, and at other times by little rocky ridges only a 
few yards across. If the animals traveled only underground, they 
then would frequently be confined to the immediate vicinity of their 
birthplaces, and inbreeding would soon occur, with consequent de- 
terioration of stock and even extermination in small areas, which 
could not subsequently be restocked. Hence, the ability and incentive 
for overland traveling is of considerable importance to many members 
of the genus. 
Very few pocket gophers have been taken in surface traps, probably 
for the reason that the ordinary mouse trap is too weak to hold such 
an animal. The present writer uses a home-made, wooden-base trap 
of the usual pattern, but the spring has almost twice the pull of the or- 
dinary, factory-made product, and the part that secures the animal 
measures two and a quarter inches each way. These obtain greater 
results, for I have taken three small gophers in them, baited with oats, 
and with no burrows nearby. Even this trap is, of course, entirely 
inadequate for large or medium-sized animals. 
The same contention obtains for moles: the ordinary mouse trap 
is out of the question, and even my larger ones can hold the smallest 
animals only when the trap can kill them instantly by smashing the 
skull. After the following manner I have caught three individuals 
of the coast mole {Scapanus orarius orarius) in oat-baited traps. 
