North American porcupine

Systematic position: The North American porcupine (Erethizon dorsatum) is a rodent belonging to the family Erethizontidae. It is a large, herbivorous mammal known for its quills and its significant impact on forestry, particularly in the northern regions of the continent.

Damaged crops and plants: This animal primarily feeds on the inner bark (phloem and cambium) of various tree species. Preferred hosts include ponderosa pine, lodgepole pine, hemlock, spruce, and fir. In terms of deciduous trees, they often target birch, willow, poplar, and maple trees.

Biology and life cycle: The North American porcupine is a solitary, nocturnal creature. It does not hibernate, remaining active throughout the winter months. During these cold periods, its diet consists almost exclusively of tree bark and needles, which puts significant pressure on timber resources and young plantation forests.

Character of damage and harmfulness: The damage is caused by the animal gnawing through the outer bark to reach the succulent cambium layer. This process, known as girdling, can cause the death of the tree if the bark is removed all the way around the trunk. Partial girdling often leads to stunted growth, wood rot, and susceptibility to secondary infections and insect infestations.

Control measures: Integrated management strategies are essential to mitigate the damage caused by these rodents:

• Installing wire mesh or metal sheet guards around individual tree trunks to prevent climbing.
• Applying commercial repellent sprays that make the bark unpalatable.
• Managing forest stands to reduce habitat suitability.
• Using controlled trapping programs in regions with high porcupine population density to protect valuable timber stands.