1170 Life-histories of Northern Animals 



does not actively interest him. Dr. Merriam, commenting on 

 this remarkable circumstance, says:^ 



"Out of 85 adult specimens killed in Lewis County during 

 the past summer (1883) there was but a single male. Two 

 other males were killed in the early autumn. Of 32 yoyng 

 killed during the same period, there were 19 males and 13 

 females, showing that the disproportion does not exist at birth. 



1 am at a complete loss to explain this enormous preponderance 

 of females among the adults. At first I was inclined to think 

 that the sexes separated during the period of bringing forth and 

 caring for the young, but, although we visited a number of 

 different localities, we were never able to find the males. 

 Thinking that they might not fly until early morning, I several 

 times went out before daylight, but females only were killed." 



Since it is desirable to offer a theory, I suggest first, that 

 the species is eminently polygamous, and second, that, like 

 Wapiti, Mountain Sheep, pheasants, and sundry other polyg- 

 amous species, the male associates with the female only during 

 the procreative season, passing the interval in distant regions, 

 usually higher and further north or otherwise less crowded with 

 their own kind, as well as freer from insect plagues. 



The great apparent increase of the Bat population in late 

 August, therefore, is a real increase caused by the arrival of the 

 flocks of males. 



If this theory is sound, we should discover far north, or up 

 in the mountains, great numbers of males that are there all 

 summer, unassociated with females. 



GESTA- Gestation lasts apparently ten months. Young are usually 



2 in number, but sometimes only i. In the Adirondack region, 

 according to Merriam, they are born during the first week of 



July. 



" Females," he says,' " killed during the latter part of June, 

 were heavy with young, but up to July i not one had given 

 birth to its offspring. All that were killed after July 4 had 

 already been in labour and were then suckling their young. 



" Mam. Adir., 1884, p. 190. ' Mam. Adir., 1884, p. 190. 



