Eptesicus furinalis (d’Orbigny)

Simmons, Nancy B. & Voss, Robert S., 1998, The mammals of Paracou, French Guiana, a Neotropical lowland rainforest fauna. Part 1, Bats, Bulletin of the American Museum of Natural History 237, pp. 1-219 : 140-141

Eptesicus furinalis (d’Orbigny)

VOUCHER MATERIAL: 12 females (AMNH *266368, 267236, *267238, *267525, *267526, *268581, *268582, *268583; MNHN *1995.887, *1995.888, 1995.889, *1995.890) and 10 males (AMNH 266367, *266369, *266373, *267235, *267237, *267529, *268580; MNHN 1995.891, *1995.892, *1995.893); see table 55 for measurements.

IDENTIFICATION: Useful descriptions and measurements of Eptesicus furinalis were provided by Davis (1966), Williams (1978), Brosset and Charles­Dominique (1990), and Ochoa et al. (1993). Four subspecies are currently recognized in South America: E. f. gaumeri (tropical Mexico through Central America to northern Colombia, Venezuela, and the Guianas), E. f. chapmani (Amazonian Colombia, Brazil, and Bolivia), E. f. furinalis (southeastern Brazil to southern Bolivia and northeastern Argentina), and E. f. findleyi (northwestern Argentina) (Davis, 1966; Williams, 1978). 15

Our voucher material conforms in all respects to previous descriptions of Eptesicus furinalis , but our initial attempt to make a subspecific determination was not successful. We compared our material to measurements of E. f. gaumeri and E. f. chapmani provided by Davis (1966), and were dismayed to discover that these taxa appear to have almost completely overlapping ranges of size variation (op. cit.: table 3). The range of varia­

tion in the Paracou series (table 55) could easily be interpreted as corresponding to either subspecies.

Although Davis (1966) published measurements of the holotypes of Eptesicus furinalis gaumeri and E. f. chapmani that suggested a significant size difference, he did not personally examine the specimens; instead, these data were provided by two different colleagues. We therefore remeasured and compared the types of gaumeri (AMNH 11040/12753) and chapmani (AMNH 37057) ourselves and found that they are more similar than previously reported (table 55). Indeed, both fall within the range of variation found in our Paracou sample in almost every dimension. Moreover, the types of gaumeri and chapmani and the Paracou specimens are all the same dark brown color above and have similar bicolored ventral fur with dark bases and tan tips. We conclude that gaumeri and chapmani cannot usefully be distinguished even at the level of subspecies. The correct name for this taxon—which seems distinct from the other South American subspecies of E. furinalis (see Williams, 1978)—is Eptesicus furinalis gaumeri Allen.

FIELD OBSERVATIONS: We captured 23 Eptesicus furinalis at Paracou, of which 14 were taken in ground­level mistnets, 8 in elevated mistnets, and 1 at a roost. Of our 14 ground­level mistnet captures, 6 were in manmade clearings and 8 were over roadside puddles. Seven of our elevated mistnet captures were made between 5 and 20 m over a narrow dirt road, and one was made at 34– 37 m over a treefall in well­drained primary forest. Our single roosting example was found behind a window shutter.