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North American Porcupine - Erethizon dorsatum
Potential Species of Concern Native Species Global Rank :
G5
State Rank :
S3S4
(see State Rank Reason below)
Agency Status USFWS :
USFS :
BLM :
FWP SWAP :
SGIN
External Links
Listen to an Audio Sample
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Copyright Jeff Rice and the Western Soundscape Archive at the University of Utah. Audio file courtesy of the Acoustic Atlas at Montana State University (www.acousticatlas.org)
State Rank Reason (see State Rank above)
Species is common and widespread across much of central and eastern Montana where sufficient security cover and den sites exists. It has declined precipitously and is possibly extirpated from the conifer forests of western Montana for reasons that are not entirely clear. It faces threats from disease, road mortality and unrestricted shooting. Fire may have both positive and negative impacts on the species.
North American Porcupine (Erethizon dorsatum ) Conservation Status Summary
State Rank: S3S4
Review Date = 09/25/2024
How we calculate Conservation Status
Rarity:
Very Uncommon Very Common
Threats:
Highly Threatened Unthreatened
Trends:
Rapidly Declining Declining Stable Increasing
Rank:
S1
S2
S3
S4
S5
Critically Imperiled Secure
See the complete
Conservation Status Report
General Description
North American Porcupine adults in the Northwest average 30 inches long and 20 pounds in weight. Round, short-legged, and slow in movement, they are protected by a coat of quills that covers all but their underside and the insides of their legs. Up to 30,000 of these modified hairs, yellowish white and black- or brown-tipped, mix with coarse guard hairs, and lay over thick, brownish underfur. The hollow quill shafts may be up to 5 inches in length and the guard hairs twice as long. They concentrate on the rump and short tail. The Porcupine sheds this coat yearly. Long, heavy claws enable the Porcupine to climb and curl up in trees. Its excellent hearing and sense of smell make up for poor vision (Foresman 2012). At night the Porcupine's bright eyes appear red. Its grunts and high-pitched cries can be heard from a distance (Burt and Grossenheider 1964). Newborns are born with teeth, eyes open, and soft quills that harden within an hour. They can climb the same day.
Species Range
Montana Range
Range Descriptions
Native
Western Hemisphere Range
Observations in Montana Natural Heritage Program Database
Number of Observations: 1165
(Click on the following maps and charts to see full sized version)
Map Help and Descriptions
Relative Density
Recency
(Observations spanning multiple months or years are excluded from time charts)
Migration
Non-migratory. However, in mountainous areas seasonal altitudinal migration may occur.
Habitat
Common in montane forests of western Montana, also occurs in brushy badlands, sagebrush semi-desert and along streams and rivers (Hoffmann and Pattie 1968). Rockfall caves, ledge caves, hollow trees, or brushpiles for dens (Dodge 1982).
Ecological Systems Associated with this Species
Details on Creation and Suggested Uses and Limitations
How Associations Were Made
We associated the use and habitat quality (common or occasional) of each of the 82 ecological systems mapped in Montana for
vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2012, Adams 2003, and Werner et al. 2004);
Evaluating structural characteristics and distribution of each ecological system relative to the species' range and habitat requirements;
Examining the observation records for each species in the state-wide point observation database associated with each ecological system;
Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of "observations versus availability of habitat".
Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.
In general, species were listed as associated with an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.
However, species were not listed as associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system,
even if point observations were associated with that system.
Common versus occasional association with an ecological system was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species as represented in scientific literature.
The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignment of common versus occasional association.
If you have any questions or comments on species associations with ecological systems, please contact the Montana Natural Heritage Program's Senior Zoologist.
Suggested Uses and Limitations
Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.
These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at:
mtnhp.org/requests ) or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.
Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.
Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.
Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).
Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species' known geographic range.
Literature Cited
Adams, R.A. 2003. Bats of the Rocky Mountain West; natural history, ecology, and conservation. Boulder, CO: University Press of Colorado. 289 p.
Dobkin, D. S. 1992. Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34. Missoula, MT.
Foresman, K.R. 2012. Mammals of Montana. Second edition. Mountain Press Publishing, Missoula, Montana. 429 pp.
Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998. Montana atlas of terrestrial vertebrates. Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT. 1302 p.
Hutto, R.L. and J.S. Young. 1999. Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32. 72 p.
Maxell, B.A. 2000. Management of Montana's amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species. Report to U.S. Forest Service Region 1. Missoula, MT: Wildlife Biology Program, University of Montana. 161 p.
Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath. 2004. Amphibians and reptiles of Montana. Missoula, MT: Mountain Press Publishing Company. 262 p.
Food Habits
In winter uses cambium, phloem, and foliage of woody shrubs and trees - ponderosa pine, lodgepole pine, perhaps spruce and fir. In spring and summer uses reproducing parts and foliage of aspen, forbs, grasses, sedges and succulent wetland vegetation (Dodge 1982)
Ecology
Has a tendency to return to familiar areas and trees. Predators include man, Fisher, Marten, American Mink, Wolverine, Mountain Lion, Canada Lynx, and Bobcat. Solitary most of year, but may den communally in winter.
Reproductive Characteristics
May be polyestrous. Parturition occurs in late April or early May, some births as late as August. Pups can eat solid food within a week, but generally remain with female throughout the summer (Dodge 1982).
Stewardship Responsibility
Based on the Montana Natural Heritage Program's latest
predicted habitat suitability model
Total species' range in Montana 381,295 km2
(100% of Montana)
Area predicted to have 315,270 km2
(83% of Montana)
Stewardship responsibility for the predicted area of suitable habitat can be broken down as follows
Total Suitable
Optimal Suitability
Moderate Suitability
Low Suitability
Federal
24%
<1%
3%
21%
State
6%
1%
5%
Local
<1%
<1%
<1%
Conservation Lands/Easements
3%
1%
2%
Private/Tribal/Unknown
67%
<1%
16%
51%
See the Habitat Suitability for Biodiversity task in Map Viewer
for a more detailed look at stewardship responsibilities within a variety of local jurisdictions.
References
Literature Cited AboveLegend: Additional ReferencesLegend: Do you know of a citation we're missing? Effects of recreation on Rocky Mountain wildlife: a review for Montana . [Montana]: Montana Chapter of the Wildlife Society. Web Search Engines for Articles on "North American Porcupine"
Additional Sources of Information Related to "Mammals"
