MAR 8 1930 



T] 



CIRCULAR No. 107 



UNITED STATES DEPARTMENT OF 

 WASHINGTON, D. C. 



FEBRUARY, 1930 



AGRICULTURE 



*7 3 *2 6 ^ 



THE NORMAL BREEDING SEASON AND GESTATION 

 PERIOD OF MARTENS 



By Frank G. Ashbrook, Principal Biologist, in Charge Division of Fur Re- 

 sources, and Kabl B. Hanson, Biologist, Director of United States Fur-Animal 

 Experiment Station, Bureau of Biological Survey 



CONTENTS 



Page Page 



Introduction... - 1 General breeding habits of martens 4 



Beginning of experiments - --- 1 Research in other countries _ 6 



Experiments of 1928 4 Summary __ 6 



INTRODUCTION 



In 1913, the Bureau of Biological Survey started preliminary 

 breeding experiments with martens (Marte.s americama) at Pritch- 

 ard. Idaho. When the fur farm at that place was abandoned in 

 1915, the martens were shipped to Washington, D. C, where for a 

 short time they were kept in the National Zoological Park. After 

 the establishment of the bureau's experimental fur farm in the foot- 

 hills of the Adirondack Mountains near Keeseville, N. Y., 6 martens 

 were shipped from Washington in August, 1916. At the end of 

 January, 1917, 4 additional martens were obtained, making a total 

 of 10 breeding animals under observation. Six of these martens 

 were lost between the breeding season of 1917 and that of 1918 — 

 3 died from disease and 2 from injuries, and 1 escaped. The breed- 

 ing stock for the year 1918 was thus reduced to 4 animals. 



Until the spring of 1!)20 the males were not allowed to run with 

 the females, except during January, February, and the early part 

 of March, which had been considered the breeding period. No 

 young were produced during the eight years from 1913 to 1920. 



BEGINNING OF EXPERIMENTS 



During the fall of 1919 and the spring of 1920, considerable diffi- 

 culty was experienced in keeping the males and females separated, 

 because they frequently burrowed under the carpet wire. They 

 mingled considerably that fall and in the winter of 1919-20, and 

 it was observed that they seemed to live together harmoniously. 

 This observation differs from those of A. H. Cocks, 1 who had con- 

 ducted experiments with martens in England. Mr. Cocks and many 

 other naturalists have reported that martens do not live happily 



1 Cocks, A. H. note on the gestation of the pine-mahten. Proe. Zool. Soc. London 

 3900 : 836-M7. 1900. 



89748'— 30 1 



