This small vespertilionid occurs throughout much of Central America, but the available material still is insufficient to permit an accurate assessment of geographic variation in that region. All but one of our specimens were trapped in mist nets. Those captured near Diriamba were taken in a net stretched across a trail bordered by high cut-banks, whereas those from other localities were netted over small streams. The one bat from Bellavista was shot as it foraged in the evening along trees bordering the hacienda yard.
Two females taken on 5 March each had swollen uteri and may have been in an early stage of pregnancy. Others taken on 13 July, 9 August, and 15 August were reproductively inactive. Males had testes that measured 2.5 (March), 3 (July), and 2 (August) mm.
We have compared our material with representative specimens from México of R. parvula and R. tumida, as defined by Goodwin (1958); we are not wholly convinced that these are valid species (rather than variable geographic races of the same species). Certainly there is need for additional investigation of the problem. Our Nicaraguan specimens most closely resemble R. t. tumida (see Goodwin, op. cit.:3), to which they are tentatively referred.
Selected measurements of two females from Boaco and a male from Matagalpa, followed by the average (and extremes) of three males and three females from western Nicaragua (Carazo and Chinandega), are, respectively: length of forearm, 30.4, 28.5, 28.3, 28.2 (27.5-29.0) mm; greatest length of skull, 12.8, 12.7, 12.8, 12.1 (11.8-12.5) mm; zygomatic breadth, 8.1, 8.4, 8.6, 8.1 (7.8-8.6) mm; mastoid breadth, 7.1, 7.2, 7.2, 6.8 (6.6-7.1) mm; breadth of braincase, 6.0, 5.7, 6.0, 5.6 (5.3-6.1) mm; postorbital constriction, 3.3, 3.0, 3.3, 3.0 (2.9-3.2) mm; length of maxillary toothrow, 4.7, 4.7, 4.5, 4.3 (4.2-4.6) mm; weight, 4.4, 4.3, 3.8, 3.5 (3.1-3.9) gms.
Tadarida laticaudata yucatanica (Miller, 1902)
One adult male (testes 5 mm) of this free-tailed bat from Potosí, 5 m, Chinandega, on the Cosigüina Peninsula, provides the only record of the genus Tadarida from Nicaragua. This specimen was netted after dark over a small stream that flowed into the Bay of Fonseca approximately 200 yards below our nets (see account of Noctilio leporinus). Other species taken in the same net included Carollia subrufa, Sturnira lilium, Eptesicus furinalis, Molossus ater, and Molossus molossus.
Selected measurements of the male are: total length, 92 mm; length of tail, 31 mm; length of hind foot, 10 mm; length of ear, 15 mm; length of forearm, 39.2 mm; weight, 10.3 gms; greatest length of skull, 17.2 mm; zygomatic breadth, 10.6 mm; postorbital constriction, 4.0 mm; breadth of braincase, 8.6 mm; length of maxillary toothrow, 6.5 mm.
Eumops auripendulus (Shaw, 1800)
A broken skull (USNM 339917) of a female of this species from Hda. Mecatepe [2 km N, 11.5 km E Nandaime, ca. 40 m], Granada, represents the only known specimen of the genus Eumops from Nicaragua. This bat was obtained by M. K. Clark on 25 August 1964, but the conditions under which it was captured are not known. Available cranial measurements are: zygomatic breadth, 12.6 mm; breadth of braincase, 10.7 mm; postorbital breadth, 4.3 mm; rostral breadth, 7.4 mm; length of maxillary toothrow, 9.1 mm; length of mandibular c-m3, 10.0 mm.
Molossus ater nigricans Miller, 1902