A Study On The Changes Of Hair Length And Pelage Thermal Insulation In Captive Squirrel(Sciurus Vulgarize Manchuricus) During Autumn Molting Period And Difference Between Summer And Winter Pelage

The pelage is one of the most important characteristics of mammals. The research about the relation between molt and environment is an important aspect in the area of animal ecology. In order to study how typical molt animals increase the thermal conductivity with decreasing temperature. Squirrels (Sciurus vulgaris manchuricus) were used as research samples to show the change of thermal conductivity with the change of pelage length during time gradient in the autumn molting period. During August10to December15in2011, the irregular sampling method was used to sample indoor captive squirrels in Harbin.2-3copies of pair, a total of30pieces of the skin were acquired each time to observe the skin color changing with sampling time backwards. Meanwhile, back and hip samples of each pair were chosen to test thermal insulation of skins of squirrels. Three ear hairs, five straight guard hairs, five undercoat hairs were sampled from different parts of squirrels, including ear, head, mid-dorsum and buttocks and then used to compare the length of ear hair, length and ratio of medulla-absent proportion of newborn straight guard hair and under hair from various parts in the molting period. At the same time, the hairs which were sampled from head, mid-dorsum, buttocks, belly and tail in August10and December15were made into cuticular impression organic glass and medulla pattern slide. The purpose is to observe the coat length, fineness, and fineness of the medulla, medullary index, scales and other morphological indicators. Results indicate:(1) The order of completely growth of newborn coat is:buttocks-dorsa-neck-head-body side, hind legs-fore.(2)With the progression of autumn molting, the pelage thermal conductivity decreased in association with increment of winter hair length, ratio of medulla-absent proportion, and reached stable at the end of hair growth.(3)Proportion of different kinds of scale types which is the straight guard hairs from central section dorsa:irregular-wave type+imbricate type> elongate valve type> wide valve type> intergradation type2> intergradation type1>imbricate type. Length and the proportion of different kinds of scale types which is the down hairs from central section dorsa:irregular-wave type> elongate valve type> intergradation type>imbricate type.(4)Medullary index from various parts of winter and summer pelage both are all in the following order:mid-dorsum>buttocks> head> tail> belly.