Porcupine damage and repellent research in the interior Pacific Northwest
[Article]
Witmer, Gary W.; Pipas, Michael J.
Porcupines (Erethizon dorsatum) rely on trees and shrubs for winter food and can cause serious, localized damage to conifers. Twenty-two percent of ponderosa trees (Pinus ponderosa) examined in southeastern Washington were damaged by porcupines. Most damage involved complete girdling of the mid- to upper boles of the larger trees (12 to 30 cm dbh) in the stand. Preliminary repellent trials with captive porcupines suggested that several materials might reduce tree damage, especially predator-associated odors. Field trials are needed to assess efficacy and duration of protection under ambient winter conditions.