Rock Chuck or Wood Chuck, both are marmots. The correct name however, for our local marmot, is the Yellow-Bellied Marmot. The marmot is the only mammal to have a USA holiday named for it (Ground Hog Day).
This large (14” to 20”) rodent loves rocky terrain where they can lay in the sun and also escape predators when alarmed. One individual always stands guard and gives an alarm call. The call will vary according to the type of predator (hawk vs. coyote, etc). It may be a “chuck”, whistle, or a trill. Rock habitats must be close to greenery, as the animal lives entirely on green vegetation of all types.
Yellow-Bellied Marmots spend 80% of their lives in burrows – this includes nighttime, as well as hibernation which lasts from August through February. They are meticulous about keeping their den and bedding clean. Their hearty appetite allows them to put on a good layer of fat for their 7 month hibernation. Sleeping late, then eating vigorously, and finally resting on a rock in the sun conserves the energy that turns into a layer of fat.
The males are “harem-polygymous” and litter sizes average a bit over 4 pups. Males leave the colony, but females tend to stay with their mothers and become reproducers at 2 years of age.
This “bear-like” rodent has a golden to rufus coat, brown head, and a yellowish-red belly. Wood Chucks are found in the east, but Yellow-Bellies are a western, intermountain species.
They are most interesting to observe, whether sunning on a large rock or scurrying across a road or trail into the closest cover.
(A big one sunning – a favorite pastime)