631 ANIMAL LIFE IX THE YOSEMITE 



The young are commonlj' referred to by naturalists as "blue-tailed 

 skinks, " since the tail is bright blue. The back of the young is dark 

 brown, relieved by two long stripes of golden yellow. The adults, on the 

 other hand, show no trace of blue on the tail and seldom any indication 

 of striping on the bod3^ The tail in the older animals is salmon pink, 

 the head coppery red, while the body is plain greenish olive. A greater 

 age contrast in one species could scarcely be imagined. This .sharp differ- 

 ence in coloration led to the description of the "red-headed skink'' of 

 the Yosemite Valley as a distinct species, Eumcces gilherti (Van Denburgh, 

 1896, pp. 350-352). The entire absence of small (that is, young) indi- 

 viduals of the " red-headed "skink and of very large "blue-tailed" skinks, 

 the capture of several individuals of intermediate size and coloration 

 (green-bodied yet with indications of striping), and the fact that in a 

 related species of skink inhabiting eastern North America a parallel change 

 in coloration is known to occur, lead noAv to the conclusion that the two 

 'forms' found in the Yosemite region are but different phases of growth 

 in one and the same species. In the northwestern part of California only 

 the striped-backed, blue-tailed phase of the skink is known to occur. 



The Western Skink is conspicuously smooth-bodied. The head merges 

 imperceptibly into the 'shoulder' region, and the body and tail are evenly 

 and finely tapered to the slender tip of the latter. The scales everywhere 

 are thin and lie so closely against the body that the animal can slip 

 through a person's fingers as if oiled. It can also slip through the piles 

 of dead leaves, in which it often seeks its insect food, with the greatest 

 ease. The legs are small and short, particularly in the adult, Avhere they 

 scarcely exceed in length the greatest diameter of the body. Locomotion 

 is accomplished more by wriggling or squirming movements of the body 

 than by use of these diminutive legs. The tail of the skink, as in most 

 other local lizards, will break off if the animal be handled roughly, and 

 will wriggle interestingly for some time. Individuals are sometimes met 

 with in nature in which the tail has been broken off and later partly regen- 

 erated. Such animals can be recognized by the stubby form of the tail. 



The local range of the Western Skink extends from the westernmost 

 rocky outcrops on the foothills near Lagrange and Pleasant Valley east- 

 ward to Yosemite Valley. In the latter place the skink has been found 

 as high as 4500 feet, at Ins])iration Point (Van Denburgh, loc. cit.). A 

 dried skin of this species was picked up at Snelling by one of our party, 

 but otherwise no evidence of its existence out on the plains of the San 

 Joaquin was forthcoming. 



Skinks are in the main cover-seeking reptiles. They do not often 

 forage in the open; they may come out, however, toward tAvilight of warm 

 summer days. The rock fences l)uilt in many parts of the foothill country 



