MAMMALS OF MARYLAND 



43 



Mating in this species usually occurs in the autumn, before the bats 

 enter hibernation. Normally the spermatozoa survive in the uterus 

 throughout the winter, and fertilization occurs the following spring. 

 Copulation, however, may occur during the winter or in the spring. 

 The gestation period probably is about 80 days, and the young are 

 bom in late May or early June. Usually only a single offspring com- 

 prises a litter, but occasionally two are produced. In about 4 weeks 

 after their birth, the young are flying and foraging for their own 

 food. Sexual maturity is achieved at about 8 months. There is only 

 one litter per season. 



The food of the little brown myotis appears to be composed entirely 

 of insects, particularly nocturnal species of moths, beetles, and bugs. 

 It has a voracious appetite, consuming large numbers of insects 

 nightly. 



This bat is long-lived; there are records of banded animals 

 recovered in good health as much as 20 years after banding. 



Specimens examined. — Cecil County: Seneca Point, 1. Garrett 

 County : Oakland, 1. MontgoTnery County : Plummers Island, 1. Dis- 

 trict of Columbia : 29. 



Other records and reports. — Baltimore County: Patapsco State 

 Park (Bull. Nat. Hist. Soc. Maryland 10 (1), p. 5, 1939). Garrett 

 County: Deep Creek Lake (banding recovery record). Montgomery 

 County: Edwards Ferry (banding recovery record). Washington 

 County: Round Top Mountain, near Hancock (banding record). 



Remarhs. — This bat is far more common than the few locality 

 records above would indicate. It is probably the most abundant bat 

 in Maryland. 



KEEN'S MYOTIS 

 Myotis keenii septentrionalis (Trouessart) 



[Vespertilio gryphus'] var. septentrionalis Trouessart, Catalogus 

 mammalium . . . , fasc. 1, p. 131, 1897. 

 Type locality. — Halifax, Nova Scotia, Canada. 



General distribution. — Eastern North America, from Newfoundland, Nova 

 Scotia, Quebce, and Ontario, south to northern Florida and west to Manitoba, 

 North and South Dakota, Nebraska, Kansas, and Arkansas. 



Distribution in Maryland. — Occurs in all sections of the State, and 

 is common. 



Distinguishing char a/)t eristics. — This bat is similar in size and color 

 to the little brown myotis {Myotis lucifugus)^ but may be distinguished 

 from that species by its long ears, which extend some 4 to 5 millimeters 

 beyond the tip of the nose when laid forward. The skull is narrower in 

 proportion to its length than that of the little brown myotis. 



