2 CIRCl'LAR 107, V. K. DFPARTMKNT OF AGRICULTURE 



together Mini will de-troy one another if both sexes are put in the 

 same pen when the female i- not in heat. 



A general belief bed prevailed thai the only time of year that 



mule marten- could be permitted to live with females was during 

 the month- of January and February. Since this was found not 

 to Ih' the case at the United State- Fur-Animal Experiment Station, 

 it was decided to allow the males to run with the females during all 

 seasons of the year, except in spring, when the young are born. 

 The martens we're reasonably tame, well fed, and in an apparently 

 healthy condition. It was natural, therefore, to expect that they 

 would 'mate and produce young. Some consideration of this problem 

 led to the theory that possibly martens in captivity breed at an- 

 other period of the year than 'do those in the wild, the commonly 

 accepted opinion being that in the wild they mate in January or 

 February. If this were true, the explanation of the fact thai there 

 Iran DO mating- and no young born at the experiment .station would 

 Ih> that the two sexes were not allowed to run together at the proper 

 time. 



On .May 1<>. 1920. the males were turned in with the females. They 

 lived together in a friendly manner until the latter part of July 

 and the early part of August. About this time they squealed con- 

 siderably and it was noted that one of the females had received a 

 severe injury to one ear. It was suspected that the martens were 

 lighting, and separating the sexes was considered. Early on the 

 morning of August VI. li>2(). the martens were making so much 

 noise that the caretaker made a special visit to the pens and saw 

 one pair mate; observations later in the day revealed this as the 

 cause of the peculiar noise. 



The male that had been seen to mate had a tumorlike growth of 

 the sheath, which it was thought might interfere with service. An- 

 other male was therefore introduced, and this one also was seen to 

 serve several times. The next day it was removed and the first one 

 returned. When this male first entered the pen, he failed to notice 

 the female, which was on the ceiling wire, but as soon as he discov- 

 ered her. he ran up, seized her by the nape of the neck, and carried 

 her down to the ground and served her. This female was seen to 

 mate on several occasions in the four days from August 13 to 16. 



On August 26, 1920. the females were put in separate pens and 

 kept there until the latter part of November, when they were again 

 turned in with the males and animals of both sexes allowed to run 

 together until April 4. 1921. They were then separated again. 



The female that wa- seen to mate during August, 1920, appeared 

 to take on considerable weight from one to two months afterwards. 

 She gave birth to a litter of three on April 15, 1921. When the 

 nest box was examined one of the young appeared to be dead, but it 

 was not removed because the female was extremely nervous and 

 excited. The next time the nest box was opened, only two young 

 could be found. There was no trace of the third. Since the mother 

 was very nervous and prone to carry the young roughly about the 

 pen whenever someone went near the den, it was deemed advisable 

 to disturb her and her litter as little as possible until the young 

 were about a month old. This female had been in captivity since 

 December. 1917, without producing any young, even though every 



