BLACK TOAD, INYO COUNTY TOAD Bufo exsul (Myers) 



Order: SALIENTIA Family; BUFONIDAE 



Distinguishing characteristics : A very small toad, adults about 2 inches long. Heavily 

 mottled with black on olive to whitish, sometimes almost solid black above, heavily 

 spotted and blotched with black below; skin smooth between warts . 



Present distribution : Two populations, at Buckhorn Springs and Antelope Springs, in 

 the Deep Springs Valley, and isolated desert basin between the White and Inyo Mountains 

 adjacent to the Death Valley system, Inyo County, California. The species has been trans- 

 planted several times to springs in the area where it was not previously found (Schuierer, 

 1962) . Success of such transplants has not been verified. 



Former distribution : Same . 



Status : Listed as rare by California Department of Fish and Game . A very restricted form 

 with narrow habitat requirements . Earlier reports of habitat destruction through irrigation 

 practices were not verified by R. R. Miller, who in 1967 found the site was relatively un- 

 changed after a period of 25 years. The population at Buckhorn Springs appears to be 

 stable and maintaining itself (Schuierer, 1972). 



Estimated numbers : Probably a breeding population of 10,000 adults (Schuierer, 1961), 

 although Myers (1942) thought the population might be as small as 700. Miller (1967) found 

 the toad to be abundant in springs, irrigation ditches, and ponds on June 27, 1967, so it 

 appears to be holding its own. 



Breeding rate in the wild : Once a year; each female produces about 120 to 150 eggs per 

 season (Savage and Schuierer, 1961), which is probably barely enough to maintain population. 



Reasons for decline : Irrigation practices in area. "The annual recanalization of the water 

 courses for irrigation has notable effect on the population. When stream modification occurred 

 after oviposition, the marsh area dried before metamorphosis." (Schuierer, 1961). 



Protective measiires already taken : Springs are located on property owned by Deep Springs 

 College, and access is restricted by the college administrators (the College has adopted this 

 toad as its mascot) . Fully protected by California law. 



Measures proposed : Establishment of wildlife monument in breeding area of species; 

 acquisition of private lands and establishment of Deep Springs Zoological Reserve proposed 

 by the State. Active surveillance of population over period of several years to determine highs 

 and lows in numbers of individuals; investigation of long-term success of known trans- 

 plantations . 



Number in captivity : Unknown, but certainly few. Occasionally collected for research 

 purposes, and can be maintained in laboratories. 



Breeding potential in captivity : Probably fairly good; most species of toads can be induced 

 to breed in captivity, and tadpoles will metamorphose. Perhaps one or two breeding 

 colonies should be established to maintain the species until the area is clearly preserved. 



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