"Merriam's chipmunk's calls are distinctive. Perched on top of a stump or rock, the chipmunks vocalize long and vigorously, and the ""chip"" sound is often followed by a burst of sound called a ""terminal pulse."" These chipmunks are usually found below the timberline, at elevations of about 2,300-2,500 m. They nest in holes in the ground, under rocks, or in logs, and occasionally in holes in trees. When they are scampering in trees they jump from branch to branch, using their fluffy tails for balance. Where their range and the range of the California chipmunk overlap, the two may interbreed."
Links:Mammal Species of the WorldClick here for The American Society of Mammalogists species account
Original description: Allen, J.A., 1889. Notes on a collection of mammals from southern Mexico, with descriptions of new species of the genera Sciurus, Tamias, and Sigmodon, p 176. Bulletin of the American Museum of Natural History, 2:165-181.