I 



CIRCULAK 10 7, U. S. DBPABTM KNT OF AOItlCUI-TURK 



On April G, 1927, a female Mint was (rapped in the wild during 

 the latter part of December, 192G, gave birth to a litter of three 

 young, two of which were reared to maturity. This female had 

 access to a male only a few hours every other day during the last 

 three weeks of February, but it is not believed that she mated at 

 any of these times, as it was observed that she would not tolerate 

 the presence of the male. When he attempted to enter her pen, she 

 invariably drove him back to his own. The indications were that 

 this female mated in the wild some time before she was trapped. 2 



In the summer of 1927 there were 4 adult females and 4 adult 

 males, and 2 young martens, one male, the other female. All but 1 

 of the 4 adult females were seen to mate in August, 1927. The 

 female that had weaned her young just a short time before refused to 

 tolerate the presence of a male. As during the previous winter, she 

 invariably drove the male out when he entered her pen. Although 

 the males were allowed to run with the females from early in July 

 until the end of February, no young were born in the spring of 1928. 



EXPERIMENTS OF 1928 



During the summer of 1928 the marten stock consisted of 13 adult 

 animals, 7 females and G males. Six of the seven females were seen 

 to mate between July 11 and August 12, most of them several times. 

 On July 19 one of the males killed the mate he had served on July 11, 

 and a little later it was decided not to use him again that season, 

 as he proved too rough and vicious when with the females. The 

 males were kept in separate pens at night and allowed to run with the 

 females during the daytime only, to facilitate better observation of 

 matings. On September 4, 1928, all the females were separated from 

 the males and placed in pens by themselves until early in the summer 

 of 1929. On April 23, 1929, one of the females that mated on July 22 

 and 23 and August 6 and 7, 1928, gave birth to a litter of young, 

 although she had not been with a male since September 4, 1928. 

 This finding demonstrated conclusively that the summer matings 

 resulted in conception and that the gestation period ranged from 

 259 to 275 days or from 8i/ 2 to 9 months. (It was not known from 

 which mating the female conceived.) 



GENERAL BREEDING HABITS OF MARTENS 



In these experiments it was found that the male and female mar- 

 tens usually live together agreeably during most seasons of the year. 

 Occasionally some of the females seemed partial to certain males, 

 especially to those with which they had been allowed to run for some 

 time prior to the oestrum. During the first week or so of the post- 

 oestrual period the male may be inclined to annoy the female, as is 

 noted by the antagonistic attitude she assumes toward him. Before 

 long, however, he discontinues attempts to mate. 



Male martens usually fight ferociously whenever they come in 

 contact; the same seems to be true of females. 



! Arhbrook, V. G.. and Hanson. K. B. pr<>oress report op marten brbbdtno kxperf- 

 ments, ('. S. Dept. Agr. Biol. Surv. Leaflet Bi-049, 5 p. ( mimeographed 1. November. 

 1927: and breeding martens in captivity, Journ. Heredity IS (11) : 499-503, illus., 

 November, 1927. 



