UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 1091 
l#C Also Technical Bulletin No. 1 of the 
^^P$*^&U Agricultural Experiment Station, University of Arizona 
Washington, D. C. PROFESSIONA L PAPER September, 1922 
LIFE HISTORY OF THE KANGAROO RAT, 
Dipodomys spectabilis spectabilis Merriam. 
By Charles T. Vorhles, Entomologist, Agricultural Experiment Station, Uni- 
versity of Arizona; and Walter P. Taylor, Assista7it Biologist, Bureau of 
Biological Survey, U. S. Department of Agriculture. 
CONTENTS. 
Page. 
Importance of rodent groups 1 
Investigational methods 2 
Identification 3 
Description 5 
General characters 5 
Color 6 
Oil gland 6 
Measurements and weights 7 
Occurrence 7 
General distribution 7 
Habitat 7 
Habits 9 
Evidence of presence 9 
Mounds 9 
Runways and tracks 10 
Signals 11 
Voice 12 
Daily and seasonal activity 12 
age. 
Habits— Continued. 
Pugnacity and sociability 13 
Sense developments 14 
Movements and attitudes 15 
Storing habits 15 
Breeding habits 16 
Food and storage 18 
Burrow systems, or dens 28 
Commensals and enemies 33 
Commensals 33 
Natural checks 34 
Parasites 35 
Abundance 36 
Economic considerations 36 
Control 37 
Summary 38 
Bihliography 40 
IMPORTANCE OF RODENT GROUPS. 
AS THE serious character of the depredations by harmful rodents 
- is recognized, State, Federal, and private expenditures for their 
control increase year by year. These depredations include not only 
the attacks by introduced rats and mice on food materials stored in 
granaries, warehouses, commercial establishments, docks, and private 
houses, but also, particularly in the Western States, the ravages of 
several groups of native ground squirrels and other noxious rodents 
in grain and certain other field crops. Nor is this all, for it has 
Note. — This bulletin, a joint contribution of the Bureau of Biological Survey and the 
Arizona Agricultural Experiment Station, contains a summary of the results of investiga- 
tions of the relation of a subspecies of kangaroo rat to the carrying capacity of the open 
ranges, being one phase of a general study of the life histories of rodent groups as they 
affect agriculture, forestry, and grazing. 
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