Porcupine

Taxonomy

Domain	Eukarya
Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Subclass	Theria
Order	Rodentia
Suborder	Hystricognatha
Infraorder	Hystricognathi
Family	Erethizontidae
Genus	Erethizon

Scientific Name

Erethizon dorsatum

Common Name

porcupine

Compiled by Whitney Cranshaw, Colorado State University:

(Erethizon dorsatum)

Hosts

Mostly coniferous trees such as ponderosa pine, but many deciduous trees and shrubs such as willow, aspen, cottonwood and serviceberry are also utilized as food and for roosts. Trees with smooth bark are preferred over rough-barked species.

Damage and Diagnosis

Porcupine damage.

Porcupines are rather large (2 to 3 feet in total length), waddling rodent with short legs, a short, thick tail with many hairs on the back and tail modified into distinctive barbed quills. They have shiny black eyes and ever-growing incisors.

Porcupines feed on foliage, buds and the inner bark. Large patches of bark are consumed. On pines and other conifers, these areas are typically golden yellow, covered with pitch and marked by wide incisor scrapes. While “barking” of the lower trunk and higher areas of large-diameter is the norm, branch barking, twig-clipping, and consumption of buds and leaves also occurs. Wooden tools, siding and other objects may also be damaged.

Life History and Habits

Porcupines occur mostly in conifer forest habitats, including pinyon-juniper areas, but can be found in mountain parks and on prairies far from trees during movements between feeding areas. They are active in all months, night and day. Breeding usually occurs in the fall and after a 200+ day gestation period, the single young is born. Softer tree parts are eaten during the spring and summer, with a higher proportion of bark and needles making up the winter diet. Porcupines are highly attracted to salt and may chew on wooden objects containing various resins or exposed to human sweat and urine (as with outhouse seats). For reasons which may be related to proximity to den sites and tannin content, certain trees are favored for heavy feeding, while other trees escape feeding injury altogether. Usually solitary, porcupines may be found roosting in groups in winter. When closely approached, porcupines usually turn their back to danger and swing their quill-laden tails in an unpredictable, lurching motion. Contrary to myth, they can not eject or “shoot” quills.

Management

Mechanical and electric fences can be used to exclude porcupines from small tree plantings or orchards. Individual trees can be protected with wire-mesh cylinders or with aluminum flashing skirts that extend to a height of 30 inches. Seedlings or very small saplings could be protected by complete enclosure within wire baskets. While not specifically labeled for use against porcupines, thiram applied for squirrel or rabbit protection may incidentally repel them. Wood treated with normal preservatives can be protected, although care should be taken not to use materials made up of metal-salt solutions (these are attractive to porcupines). There are no legal poisons for porcupines. Control of porcupines by trapping or shooting should be rare and limited to particularly troublesome individuals. Eradication attempts will likely meet with failure due to reinvasion. In summary, exclusion techniques, promotion of non-attractive plants and tolerance should be the norm in most situations.

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.