SPADE-FOOT TOAD 655 



they were attracted by the special scent on the traps. On May 8 another 

 individual was obtained at the same locality. Two more were obtained in 

 traps set toward the lake from Mono Mills, on June 20, 1916. 



The Western Spade-foot Toad is even more reclusive than the ordinary 

 toads (Bufo) and frequently escapes observation entirely, even by natural- 

 ists, in a country where it occurs in some numbers. The animals are 

 strictly nocturnal save when rains during the summer months bring them 

 out to spawn. They are to a considerable degree opportunists, and make 

 use of the ephemeral rain pools as places in which to deposit their eggs. 

 Female Spade-foots captured on May 5 and 8, and June 20, 1916, contained 

 numbers of eggs which would have been ready to lay in the near future. 



California Toad. Bufo boreas halophilus Baird and Girard*^ 



Field characters. — Size large, adult females being 4—5 inches long (males 3% inches 

 or less) ; skin rough with numerous large 'warts' (pi. 60a) ; a large raised gland (paro- 

 toid) on each shoulder behind ear region; space between the two glands broader than 

 width of one gland; pupil round. Upper surface grayish green, with numerous large 

 irregular spots or streaks of black; a conspicuous streak of white extends along middle 

 of head and back ; under surface dull yellow, sometimes with numerous small black spots. 

 Voice: A rather deep-toned prolonged trilling, with rhythm slow. 



Occurrence. — Common resident in western part of Yosemite region, below 4500 feet 

 altitude. Eecorded from Yosemite Valley westward to Snelling and Lagrange. Lives in 

 sheltered situations on or below ground, coming forth at dusk of evening. Solitary 

 except at spawning time. 



The California Toad is common in the lowland and foothill territory 

 in the western part of the Yosemite region, and upon two occasions it was 

 found on the floor of Yosemite Valley. Its range is separated from that 

 of the Yosemite Toad by a considerable altitudinal interval, involving the 

 upper two-thirds of the Transition Zone. East of the mountains is found 

 a close relative, the Northwestern Toad. 



The California Toad, and toads in general (of the genus Bufo), may 

 be distinguished from other tail-less amphibians of the Yosemite region 

 by the presence of a large raised area, the parotoid gland, on each 

 'shoulder' behind the ear membrane (pi. 60a). The Spade-foot {Scaphio- 

 pus) may show a slight elevation in the same region, but that animal 

 may be recognized otherwise by its cutting 'spade' on the hind foot and 

 by the elliptical pupil in the eye. True toads (Bufo) have the pupil 

 circular. The California and Northwestern toads have the parotoid glands 

 rather long and widely separated, whereas the Yosemite Toad has these 



43 A closely related subspecies, the Northwestern Toad, Bufo boreas boreas Baird and 

 Girard, occurs at Walker Lake and near Williams Butte. It is distinguished from the 

 California Toad by darker coloration and by having the spread of the hind foot (from 

 tip of first toe to tip of fifth toe) more than 36 per cent of body length. The habits 

 of the two subspecies are alike, so far as known. 



