Reproduction and growth of Eutamias quadrivittatus in southeastern Utah

Wadsworth, Carl

The growth and development of four litters of Colorado chipmunks (Eutamias quadrivittatus hopiensis) are described. Mating in southeastern Utah occurs in late February or early March. Young are born from 1 to 15 April and first appear above ground in May, but do not reach breeding age until the following spring. One litter of young per year is produced. The mean number per litter was 5.25 for the litters born in captivity. The average weight on the day following birth was 2.8 ± .32 grams and the average daily increase in weight was 0.50 gram during the first 90 days of life. The eyes opened at 29 to 33 days, the pinnae unfolded in 2 to 3 days, and the auditory meatuses opened at 28 to 29 days old. The irruption of the teeth were as follows: the lower incisors appeared in 10 to 12 days, the upper incisors in 20 to 22 days, and the cheek teeth in 34 to 37 days. The dorsal dark and white stripes appeared in 10 days. Juvenile chipmunks molt twice during their first year. The molt proceeds from anterior to posterior in June and July and from posterior to anterior in September and October.

Reproduction and growth of Eutamias quadrivittatus in southeastern Utah

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