658 ANIMAL LIFE IX THE YOSEMITE 



skin on its upper surface is plain olive green marked with minute scattered 

 dots of black, each of which is rimmed with white. The female, on the 

 other hand, has the back and sides thickly marbled with irregular but 

 clearly defined patches of black outlined by white. Low rounded warts 

 of dark color are centered in these areas of black. The ground color 

 between the spots varies from dull brown to white. Whether these marked 

 differences in coloration and markings are maintained at other times of 

 the year is not known definitely, though the few animals collected in early 

 spring and in autumn would indicate that such is the case. Tn some species 

 of amphibians such as the California Toad the male takes on a green- 

 colored smoother-skinned appearance in the breeding season and then 

 reverts to a condition more like the female for the remainder of the year. 

 The males of the Yosemite Toad, as is true of all other true toads (genus 

 Bufo), develop on the upper side of the 'thumb' and two adjacent digits 

 of the fore limb an area of roughened brown skin during the breeding 

 season. 



The Yosemite Toad undoubtedly hibernates for a considerable period 

 of time during the winter months, when snow covers the higher country 

 and the temperature goes below the freezing point. Our observations were 

 not continued in the higher altitudes long enough to determine the actual 

 dates of spring emergence and fall disappearance. On May 20, 1919. we 

 visited Peregoy Meadow and found the males there already out and trilling 

 loudly ; on September 3, 1915, at Vogelsang Lake, a single individual was 

 collected. In all probability some of these toads emerge toward the end 

 of April and a few may be out until early October. The hardihood of 

 the species is indicated by the way in which the adults jubilate in the 

 melting snow water during the spring and early summer months. 



The winter season is spent in some retreat in the ground, presumably 

 below the frost line; any individual toad which chances to seek a shelter 

 above that level will in all probability be killed when the cold of winter 

 freezes the upper ground. During that part of the summer not devoted to 

 Q^^ laying the toads spend the day solitarily in damp situations at the 

 surface of the ground under logs or stones. A toad seen abroad during 

 the day near Porcupine Flat quickly betook itself to a pool of water beneath 

 a log. Several small individuals were observed on a hot, dry, sandy flat 

 near Ragged Peak in July, and near Vogelsang Lake one individual was 

 found beneath a rock in a damp heather patch 20 feet from a stream. 



Immediately or very soon after emerging from their winter liil)erna- 

 tion these toads repair to pools and small streams in the wet meadows, 

 and continue there until the eggs are deposited or even longer. The males 

 precede the females, as at Peregoy Meadow there were many males present 

 on May 20, 1919, while the onlv females fouiul were small non-breeding 



