Life History of the Kangaroo Rat

Life History of the Kangaroo Rat,
by

Charles T. Vorhies and Walter P. Taylor This eBook is for the use of
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Title: Life History of the Kangaroo Rat
Author: Charles T. Vorhies and Walter P. Taylor
Release Date: March 11, 2006 [EBook #17966]
Language: English
Character set encoding: ISO-8859-1
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HISTORY OF THE KANGAROO RAT ***

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UNITED STATES DEPARTMENT OF AGRICULTURE
BULLETIN No. 1091

Also Technical Bulletin No. 1 of the Agricultural Experiment Station
University of Arizona
Washington, D. C. PROFESSIONAL PAPER September 13, 1922
LIFE HISTORY OF THE KANGAROO RAT Dipodomys spectabilis
spectabilis Merriam
BY
CHARLES T. VORHIES, Entomologist Agricultural Experiment
Station, University of Arizona; and
WALTER P. TAYLOR, Assistant Biologist Bureau of Biological
Survey, U. S. Department of Agriculture

CONTENTS
Importance of Rodent Groups 1 Identification 3 Description 5
Occurrence 7 Habits 9 Food and Storage 18 Burrow Systems, or Dens
28 Commensals and Enemies 33 Abundance 36 Economic
Considerations 36 Summary 38 Bibliography 40
[Illustration]
WASHINGTON GOVERNMENT PRINTING OFFICE 1922
[Illustration: PLATE I.--Banner-tailed Kangaroo Rat (Dipodomys
spectabilis spectabilis Merriam).
From Dipodomys merriami Mearns and subspecies, which occur over
much of its range, this form is easily distinguished by its larger size and
the conspicuous white brush on the tail.]

UNITED STATES DEPARTMENT OF AGRICULTURE

BULLETIN No. 1091
Also Technical Bulletin No. 1 of the Agricultural Experiment Station,
University of Arizona
Washington, D. C. PROFESSIONAL PAPER September, 1922
LIFE HISTORY OF THE KANGAROO RAT,
Dipodomys spectabilis spectabilis Merriam.
By CHARLES T. VORHIES, _Entomologist, Agricultural Experiment
Station, University of Arizona; and WALTER P. TAYLOR, Assistant
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 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 Bibliography 40
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 investigations 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.

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 been found that such rodents
as prairie dogs, pocket gophers, marmots, ground squirrels, and rabbits
take appreciable and serious toll of the forage on the open grazing
range; in fact, that they reduce the carrying capacity of the range to
such an extent that expenditures for control measures are amply
justified. Current estimates place the loss of goods due to rats and mice
in warehouses and stores throughout the United States at no less than
$200,000,000 annually, and damage to the carrying capacity of the
open range and to cultivated crops generally by native rodents in the
Western States at $300,000,000 additional; added together, we have an
impressive total from depredations of rodents.
The distribution and life habits of rodents and the general consideration
of their relation to agriculture, forestry, and grazing, with special
reference to the carrying capacity of stock ranges, is a subject that has
received attention for many years from the Biological Survey of the
United States Department of Agriculture. As a result of the
investigations conducted much has been learned concerning the
economic status of most of the more important groups, and the
knowledge already gained forms the basis of the extensive
rodent-control work already in progress, and in which many States are
cooperating with the bureau. If the work is to be prosecuted
intelligently and the