K.A.IBAB SQUIRREL Sciurus kaibabensis (Merriam) 



Order: RODENTIA Family: SCIURIDAE 



Distinguishing characteristics : A black tree squirrel, tassel-eared, white tail. 



Present distribution : Kaibab plateau on north side of Grand Canyon, Arizona, an area 

 of approximately 30 by 70 miles; closely associated with yellow pines. Apparently 

 restricted to Kaibab National Forest and Grand Canyon National Park lands . 



Former distribution : Probably the same since historic times. 



Status : Restricted in range . 



Estimated numbers : Approximately 4,000 in 1968 (Webb, 1969). 



Breeding rate in the wild : One or two litters (3-4 each) annually. 



Reasons for decline : Automobile traffic and disease the most conspicuous causes of 

 mortality. Possibly the long history of complete fire prevention on the Kaibab area has 

 resulted in a deterioration of the habitat for this species . 



Protective measures taken : Complete legal protection for many years. North rim of 

 Grand Canyon National Park serves as a sanctuary. 



Measures proposed : Continue complete legal protection. Preservation of Gambel oak 

 and yellow pine (squirrel feeds on the cambium layer) . Efforts should be made to get 

 a captive breeding program into operation. 



Number in captivity : 5 to 10. 



Breeding potential in captivity : Good . 



Remarks : The squirrel population fluctuates from year to year for reasons unknown. 

 Dr. Joseph G. Hall, who studied the species under sponsorship of the National Park 

 Service, wrote on August 7, 1964, that, in his opinion, the population was at its 

 highest about 30 years ago and that it "is now at its lowest ebb in a half century." 

 The Arizona Game and Fish Commission believes that the status of this species is about 

 optimum for its limited range and the species is not threatened. 



References: 



Allen, G. M. 1942. Extinct and Vanishing Mammals of the Western Hemisphere. 



American Committee for International Wildlife Protection, Special Publ . 11, 



pp. 42-44. 

 Goldman, E. A. 1928. The Kaibab or white-tailed squirrel . Jour. Mamm . , 



9:127-129. 

 Hall, J. G. 1964. Report on Kaibab squirrel investigations. MS report. 



National Park Service. 



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