Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Wildlife and Fisheries Science


The summer home ranges, food habits, cover preferences, population dynamics, metabolic rates, growth rates, and taxonomic characteristics were determined for porcupines (Erethizon dorsatum) in northwestern South Dakota. The summer home ranges were 158.2 ha for adult females, 90.4 ha for juveniles, and 57.9 ha for adult males. The population was 34 percent adult males, 16 percent juvenile males, 34 percent adult females, and 15 percent juvenile females. The preferred daytime cover choice was silver buffaloberry (Shepherdia argentea), followed by snowberry (Symphoricarpos occidentalis), earth dens, forbs, and low brush. Shrubs were the most important item in the diet, then trees, forbs, and grasses. Buffaloberry was the most frequently eaten shrub, hawthorne (Crataegus spp.) was second. Ponderosa pine (Pinus ponderosa), willow (Salix spp.) and green ash (Fraxinus pennsylvanicus) were the most common tree species consumed. Alfalfa (Medicago sativa), wild licorice (Glycyrrhiza lepidota), yellow sweetclover (Melilotus officinalis) and bigtop dalea (Dalea enneandra) were the most frequently utilized forbs. Porcupine assimilation efficiency of pine inner bark was 83.6 percent; the assimilation efficiency of alfalfa was 77.6 percent. The resting metabolic rate of adult porcupines in thermoneutrality was 64.67W(kg)0'77 kcal/day. The upper critical temperature was 23 C. Rises in metabolic rate with ambient temperatures above 23 C followed the equation RMR = 15.24 + 1.15 X, where X is ambient temperature. Skull characteristics, external measurements, and coloration indicated that the population in Harding County, S. D. is an intergrade between E. dorsatum bruneri Swenk and E. dorsatum epixanthum Brandt.

Library of Congress Subject Headings



Includes bibliographical references (pages 63-67)



Number of Pages



South Dakota State University


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