Molt in the Pocket Gopher, Thomomys bottae

This paper is an attempt to establish the sequence of molt patterns and the number of annual molts in pocket gophers from Davis (Thomomys bottae navus) and O' Neals (T. b. mewa), California. Investigations were conducted between 1949 and 1955 and were based on laboratory and field studies of more than 600 animals. Histological aspects of hair development are also described herein. Acknowledgements are extended to Jay C. Quast, Nathan W. Cohen, and Henry E. Childs, Jr., for aid in live-trapping and in recording field molt data. Mr. Childs also prepared most of the flat study skins. Seth B. Benson and Robert L. Rudd are gratefully acknowledged for their comments on the study and for reading the manuscript. Live-trapped gophers.— Pocket gophers (T. b. mewa) were periodically live-trapped on a 3.7 acre plot at the San Joaquin Experimental Range, O' Neals, San Joaquin County, California, from 1949 to 1954 (Howard and Childs, MS). Each time an animal was captured, the position of any molt line present (where visible) was recorded on 5 × 8 inch cards containing mimeographed outlines of dorsal and lateral views of a gopher. The pelage color and also the comparative length of hair, if apparent in the two seasonal pelages of molting gophers, were also entered on the card. A total of 789 of these recordings was obtained from 198 individuals. Fourteen gophers living on the plot were dyed as an additional procedure, but this was at a time when trapping was less frequent. Nevertheless, during the ensuing fourteen months, ten of the dyed animals were recaptured a total of 21 times.