Erethizon dorsatum, commonly known as the North American porcupine, is a large rodent distinguished by its quills. It inhabits forests, grasslands, and deserts across North America. Notable for its slow, waddling gait, this herbivore primarily feeds on leaves, twigs, and bark. Its quills are a unique defense mechanism against predators.

Erethizon dorsatum, commonly known as the North American porcupine, is native to North America. It is widely distributed across Canada, the United States, and into northern Mexico. Its range extends from Alaska and northern Canada down through the western United States, including the Rocky Mountains and the Great Lakes region, and into parts of the northeastern and western United States.

The North American porcupine typically inhabits a variety of forested environments, including deciduous, coniferous, and mixed forests. It is also found in shrublands, tundra, and desert edges. The species is adaptable to different climates ranging from cold, northern boreal forests to warm, arid deserts.

Erethizon dorsatum occupies an ecological niche as a herbivore, feeding primarily on leaves, twigs, and green plants in the summer, and bark and evergreen needles in the winter. It plays a role in shaping the vegetation structure and serves as prey for several predators such as fishers, wolves, and large birds of prey. The porcupine's ability to climb trees allows it to exploit arboreal resources and avoid some ground-based predators.