Marmots are large rodents that often become nuisances to gardeners, farmers, and homeowners due to their appetites and burrowing habits. The yellow-bellied marmot is the most common species in the United States and a close relative of the woodchuck. Also known as rockchucks or whistle pigs, yellow-bellied marmots are social creatures that live in communities of 10 to 20 individuals. During the spring and summer, the animals undergo a period of hyperphagia, a feeding frenzy designed to fatten the marmots so they can survive the coming winter. By huddling together in underground burrows lined with hay or grass, marmots hibernate for up to 200 days at a time, easily spending half of their 13 to 15 years of life asleep.

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Biology & Behavior

Yellow-bellied marmots also known as a rock chuck are small or medium sized rodents. They have sturdy bodies with short, wide heads. Their bodies are covered in coarse hair that is lighter on the tips and darker at the base. This makes them look light brown overall. They have yellowish patches of hair on the sides of their neck, and white spots between their eyes. Their belly is yellow or orange-brown, which is how they get their name. Their feet are tan, hazel, or dark brown. Different subspecies have different colors. Yellow-bellied marmots have small, furry ears. Their back feet have oval pads, and their claws are short and a little bit curved. Yellow-bellied marmots range from southwestern Canada throughout the western United States, including the Rockies, Sierra Nevada and the Intermountain West. Males are longer than females and quite a bit heavier. Males weigh 6.5 to 11.5 pounds, and are usually around 8.5 pounds. Females weight 3.5 pounds to 7.8 pounds, and usually are about 6 pounds. Yellow-bellied marmots can live in colonies, in pairs, or alone. Usually, males mate with more than one female. Yellow-bellied marmots have one breeding season per year right after they wake up from hibernating for the winter. The breeding season lasts about two weeks. The young grow inside their mother for about 30 days. Females have 3 to 8 pups, and 4 pups on average.



Yellow-bellied marmots cause lots of damage to yards, lawns, flower beds and gardens due to tunneling, gnawing/eating of fruits and vegetables and ornamental shrubs and grasses. Occasionally marmots cause structural damage to dikes and foundations, power cables, utility lines and even rubber hoses in parked vehicles. Their mounds can damage mechanical harvesting equipment and weaken cement structures. Marmots carry ticks, which transmit Rocky Mountain spotted fever or Lyme disease. They can also be carriers of the plague and other diseases including rabies. ​

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