Although Eastern Chipmunks are much in evidence during our current November heat wave, these lively rodents will soon retreat underground to their maze of interconnecting tunnels for the winter. This burrow system usually has one unobstructed entrance with the opening of other tunnels that lead to the surface plugged with leaves. A chipmunk may dig part of the burrow system using its forefeet and cheek pouches to loosen and transport soil, but the renovation of old root channels and existing burrows of other mammals is the primary method of burrow construction. The two-inch diameter tunnels are roughly 12 to 30 feet long and typically 18 to 36 inches deep. Off of these tunnels are several food galleries as well as a chamber six to ten inches in diameter which contains a nest of leaves.
Chipmunks reside in their subterranean environs from mid-November until early March – late April, with local snow depth and temperatures influencing the duration. They are not true hibernators and accumulate little body fat prior to winter. Throughout the winter chipmunks are aroused from their state of torpor every week or two and snack on their underground caches of food (up to 5,000 – 6,000 nuts per chipmunk, according to one source). During mid-winter thaws, some chipmunks may leave their burrows, even digging through several feet of snow to forage for seeds in nearby areas where the snow has melted and the forest floor is exposed.
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