Shadow Chipmunk

Allen's chipmunk's total length measures about 229–261 mm (9.0–10.3 in), with a tail length of 90–111 mm (3.5–4.4 in). Adults weigh 66.8–108.5 g (2.36–3.83 oz), with females being larger than males on average as the species exhibits a dimorphism ration of 1.033. The coastal subspecies (Neotamias senex pacifica) is characterized by an overall dark fur complexion with indistinct dorsal stripes, similar to that of Neotamias townsendii. The inland subspecies (Neotamias senex senex) have a much lighter complexion, with brownish-yellow fur tinged with smoky gray. During the summer and winter, it displays a distinctive black median dorsal stripe along its back.

The coastal subspecies is found solely in the redwood forest belt of California that extends from the Pacific coast to about 32 km (20 mi) inland, and ranges from the Eel River of Humboldt County in the south to the Klamath River of Del Norte County in the north. The inland subspecies's range starts at Shaver Lake, Fresno County and stretches northwards and westwards into the Sierra Nevada, Cascade, Warner, and Yolla Bolly ranges, and bordering the eastern-most boundary of the coastal subspecies' range.

Allen's chipmunk exhibits a generally social nature. It has a chip vocalization that typically consists of a rapid series of calls, with each call being another rapid series of 3–5 syllables. It has a mean call duration of 0.81 seconds with 0.39 seconds between each syllable; calls are of a medium frequency, with a minimum frequency of 4.59 kHz and a maximum of 12.98 kHz. Its call has been observed as being used as an alarm call to possible threats. When approached by a predator, the chipmunk falls quiet and stays motionless, then resumes the alarm call when the predator has passed by. It has often been observed that when one chipmunk began to call, others would join in for up to 15 minutes. It is diurnal, and hibernates from November through to March; it is one of the few species of chipmunks in North America that undergo seasonal fat accumulation, increasing their weight by as much as 20% by November in order to make it through the winter months. Before and after hibernation, the chipmunk tends to become quiet, secretive, and overall inactive. However, as more chipmunks emerged from hibernation in the spring, the population has been observed to become loud and aggressive.

Diet. Allen's chipmunk is omnivorous, with its diet consisting of fungi, insects, seeds, flowers, and fruit. …