32 



NORTH AMERICAN FAUNA 75 



Fig. 19. Big naked- 

 backed bat, Ptero- 

 notus gymnonotus. 

 Photo by R. K. 

 LaVal 



Pteronotus gymnonotus 

 Big Naked-backed Bat 



Big naked-backed bats are widely distributed from Veracruz, Mexico, to 

 southwestern Brazil (Fig. 19). The species is monotypic. 



Although known from a variety of habitats, this species is primarily an in- 

 habitant of lowland forests. Roosts are usually in caves, and colonies may be quite 

 large. Pteronotus gymnonotus is an aerial insectivore. Reproduction has not been 

 studied, but other members of the family are monestrous (Wilson 1973b). 



The first Costa Rican record of this species was from Boruca (Sanborn 1932). 

 Starrett and Casebeer (1968) shot individuals foraging above roadways in two 

 localities in southern Costa Rica. Our specimen is the first record for the La Selva 

 region. It was taken in a mist net set over the Rio Cascante in an area where the 

 forest had been cleared for pasture. 



Specimen examined (1)— 1 km S, 1 1 .5 km E of San Miguel, 680 m [1 female, 

 USNM]. 



