Eptesicus brasiliensis (Desmarest, 1819)

Velazco, Paúl M., Voss, Robert S., Fleck, David W. & Simmons, Nancy B., 2021, Mammalian Diversity And Matses Ethnomammalogy In Amazonian Peru Part 4: Bats, Bulletin of the American Museum of Natural History 2021 (451), pp. 1-201 : 130-131

Eptesicus brasiliensis (Desmarest, 1819)

VOUCHER MATERIAL (TOTAL = 4): Jenaro Herrera (MUSM 5596, 5597), Nuevo San Juan (MUSM 13201), Quebrada Sábalo (MUSA 15237); see table 59 for measurements.

UNVOUCHERED OBSERVATIONS: None.

IDENTIFICATION: Eptesicus brasiliensis is distinguished from other Neotropical congeners by its medium size (forearm 40–47 mm, greatest length of skull 16–18 mm), relatively short (<7 mm) dorsal fur, brownish ventral fur, U-shaped nasal opening, and inflated rostrum (Davis, 1966; Miranda et al., 2006; Davis and Gardner, 2008; López-Baucells et al., 2018). Descriptions and measurements of E. brasiliensis were provided by Davis (1965, 1966), Barquez et al. (1999), Lim et al. (2005), Miranda et al. (2006),

TABLE 59

External and Craniodental Measurements (mm) and Weights (g) of Eptesicus

brasiliensis and E. furinalis from the Yavarí-Ucayali Interfluve

Davis and Gardner (2008), and Sánchez et al. (2019). Four subspecies are currently recognized: E. b. arge (northern Argentina, southern Brazil, Paraguay, and Uruguay), E. b. brasiliensis (eastern Brazil), E. b. melanopterus (lowlands of Colombia, Guyana, Surinam, Venezuela, and the Amazon basin of Brazil), and E. b. thomasi (western Amazon basin of eastern Ecuador and Peru) (Davis and Gardner, 2008). Based on distribution, our voucher material from the Yavarí-Ucayali interfluve should correspond to E. b. thomasi . However, most of the characteristics noted by Davis (1966) as diagnostic of E. b. thomasi are measurements that overlap those of other subspecies, and in our experience populations of E. brasiliensis are highly variable. Until comprehensive studies including larger sample sizes and genetic data became available, we recommend against formally recognizing subspecies.

Ascorra et al. (1993) and Fleck et al. (2002) correctly identified their specimens from Jenaro Herrera and Nuevo San Juan, respectively. The voucher material we examined from the Yavarí- Ucayali interfluve conforms to previous descriptions of Eptesicus brasiliensis , with measurements that fall within the range of size variation previously documented for the species.

REMARKS: The only recorded capture of Eptesicus brasiliensis accompanied by ecological information from our region is an adult male that we found beneath a sheet of exfoliating bark on the underside of a fallen tree about 50 cm above the ground in a Matses swidden near Nuevo San Juan on 31 May 1998. One individual of Myotis albescens was found roosting beneath another sheet of bark on the same fallen tree at the same time. Both bats were torpid when this roost was discovered in midafternoon.