The yellow-bellied Marmot (Marmota flaviventris), also known as the “Rock Chuck”, is a ground squirrel in the marmot genus. It lives in the mountains of the western United States and Canada, including the Rocky Mountains and the Sierra Nevada. It inhabits sub alpine and alpine regions. They typically live above 6,561 feet (2000 m) of elevation. Yellow-bellied Marmots usually weigh between 5 and 11 pounds (2 and 5 kg) when fully grown. They get fatter in the fall just before hibernating. A marmot’s habitat is mostly grass and rocks with few trees. Their territory is about 6 acres (20,000 to 30,000 square meters) around a number of summer burrows.
Marmots choose to dig burrows under rocks because predators are less likely to see their burrow. Predators include wolves, foxes, and coyotes. When a marmot sees a predator it whistles to warn all other marmots in the area (giving it the common name the whistle pig). Then it typically hides in a nearby rock pile.
Marmots reproduce when about 2 years old. They live in colonies. A colony is a group of about 10 to 20. Each male marmot digs a burrow soon after he wakes up from hibernation. He then starts looking for females. By summer he has 1 to 4 females living with him. Litters usually average 2 to 5 offspring per female. The male defends 1-4 mates at the same time.
Yellow-bellied Marmots are daily like most mammals. The marmot is also an omnivore, eating grass, leaves, flowers, fruit, grasshoppers, and bird eggs.
Marmots are not hunted for sport but are sometimes killed by farmers.
Yellow-bellied Marmots include “toilet rooms” in their burrows as well as living rooms, bedrooms and eating rooms.