174 EXTINCT AND VANISHING MAMMALS 



killing of females. The fact that they are more or less subject 

 to a periodic cycle of decline, probably due to disease or failure 

 of food supply through dying off of certain rodents that form 

 a staple diet, or to both factors combined, probably would 

 have an influence on the numbers of a small population, and 

 when these factors coincide with other unfavorable circum- 

 stances a danger point is reached. Martens are relatively easy 

 to trap, so that this trait adds to the hazard of their lives. 

 Finally, an important factor in their decline from a peak of 

 numbers lies in the fact that their gestation period is long, so 

 that killing of females often involves the death of a potential 

 litter. At the present time there have been various attempts 

 made to raise martens in captivity, but with only moderate 

 success. Young are born in March and April and are independ- 

 ent by some three months later. Further experiments being 

 carried on by the U. S. Fish and Wildlife Service will doubtless 

 provide a better knowledge of the best methods of management. 

 In 1936 a five-year closed season on martens in the United 

 States was urged by the Chief of the Biological Survey and en- 

 dorsed by the American Wildlife Conference. Some idea of the 

 number annually killed in western Canada may be gained from 

 the statement of Cameron (1936, p. 625) that the fur yield of 

 the Northwest Territories for the year 1933-34 included no 

 less than 5,580 marten pelts. 



FISHER; PENNANT'S MARTEN; "PEKAN"; "BLACK CAT" 

 MARTES PENNANTI (Erxleberi) 



Mustela pennanti Erxleben, Syst. Regni Anim., vol. 1, p. 470, 1777 (eastern Canada). 



SYNONYMS: Mustela canadensis Schreber, Saugthiere, vol. 3, p. 492, pi. 134, 1778 

 (eastern Canada); Mustela melanorhyncha Boddaert, Elenchus Anim., p. 88, 1784 

 (eastern Canada, based on Pennant); Viverra piscator Shaw, General Zool., vol. 

 1, p. 414, 1800 (eastern Canada, based on Pennant); Mustela nigra Turton, 

 Tiirton's ed. Linnaeus's Systema Naturae, vol. 1, p. 60, 1806 (eastern Canada, 

 based on Pennant); Mustela godmani J. B. Fischer, Synopsis Mamm., p. 217, 1829 

 (Pennsylvania); Mustela canadensis pacifica Rhoads, Trans. Amer. Phil. Soc., 

 new ser., vol. 19, p. 435, Sept. 1898 (Lake Keechelus, Kittitas County, Washing- 

 ton). 



A possibly valid race lately distinguished is 



Maries pennanti columbiana Goldman, Proc. Biol. Soc. Washington, vol. 48, p. 176, 

 Nov. 15, 1935 (Stuart Lake, near headwaters of Fraser River, British Columbia). 



FIGS.: Nelson, 1916, p. 446. upper fig. (col.); Grinnell, Dixon, and Linsdale, 1937, 

 vol. 2, pi. 5 (col.); figs. 72-81 (details, skull, habitat). 



