Uteri of eight females obtained in the period May 23 to 31 were enlarged; two females collected on June 29 carried single embryos that measured 20 and 22. A lactating female was taken on August 3, but three other adult females taken early in the same month evidenced no reproductive activity. Testes measured 2 to 4 in three May-taken males and 4 in each of two from June.
Two males obtained June 16 and 23 were molting as evidenced by new hairs under the old pelage over much of the body.
Myotis volans that we examined for ectoparasites harbored chiggers, Leptotrombidium myotis (Ewing), and fleas, Myodopsylla gentilis Jordan and Rothschild.
Lasionycteris noctivagans (LeConte, 1831)
Silver-haired Bat
A single female, which contained two embryos that measured 4, represents the only record of a silver-haired bat from Harding County. This specimen was shot at dusk on June 1, 1968, as it foraged over a small pond in Deer Draw of the Slim Buttes (10 mi. S and 5 mi. W Reva). Several other bats believed to be of this species were seen at the same place that evening. We initially assumed that these were late migrants, but recent findings indicate that this species is a common summer inhabitant of the Long Pine Hills in adjacent Carter County, Montana, and likely, therefore, also a resident in favored sites in Harding County.
Eptesicus fuscus pallidus Young, 1908
Big Brown Bat
Specimens examined (11).—NW 1/4 sec. 15, R. 5 E, T. 22 N, 3; 7 mi. N, 2 mi. W Camp Crook, 3300 ft., 2; 10 mi. S, 5 mi. W Reva, 6.
The big brown bat is a common inhabitant of the Slim Buttes and North Cave Hills, where individuals were shot or netted as they foraged over water or among trees late in the evening.