Photoperiod and Fur Lengths in the Arctic Fox (Alopex lagopus L.)

• Main Authors: Underwood,Larry S, Reynolds,Patricia
• Other Authors: ALASKA UNIV ANCHORAGE ARCTIC ENVIRONMENTAL INFORMATION AND DATA CENTER
• Format: Text
• Language: English
• Published: 1980
• Subjects: Anatomy and Physiology; Stress Physiology; *ADAPTATION(PHYSIOLOGY); *FUR; HEAT TRANSFER; SEASONAL VARIATIONS; LENGTH; ARCTIC REGIONS; CARNIVORA; PHOTOPERIODISM; *Foxes; Alopex lagopus; Arctic; Arctic Fox
• Online Access: http://www.dtic.mil/docs/citations/ADA085976; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA085976

Pelage is seasonally dimorphic in the Arctic fox. During the winter, fur lengths are nearly double similar values taken during the summer. Considerable site-specific differences in fur length are noted. In general, body sites which are exposed to the environment when the fox lies in a curled position show greater fur lengths in all seasons and greater seasonal variations than body sites that are more protected during rest. Well-furred sites may tend to conserve heat during periods of inactivity, and scantily furred sites may tend to dissipate heat during periods of exercise. Growth of winter fur may compensate for the severe cold of the arctic winter. Changes in fur lengths indicate a definite pattern in spite of individual variations. During the fall, fur lengths seem to lag behind an increasing body-to-ambient temperature gradient. Both body-to-ambient temperature gradients and fur lengths peak during December through February. From March through June, gradual environmental warming is accompanied by a decrease in average fur lengths. Thus, there appears to be a parallel between the body-to-ambient temperature gradient and fur length -- growth of fur parallels annual changes in ambient temperature and photoperiod. It may be that the onset of fall molt in the Arctic fox is indigenously controlled, while spring molt may be more related to either changes in temperature, photoperiod, or both.