Molossops abrasus
Cinnamon Dog-faced Bat
Description
Molossops abrasus is in the Family Molossidae, the free-tailed bats. The common name
is Cinnamon dog-faced bat. There is also other scientific names given; Cynomops
abrasus, Molossops brachymeles, and Molossops abrasus cerates (Simmons and Voss
1998).
The dorsal fur is a uniform brown, dark brown or chestnut. The ventral fur is similar to
the color of dorsal fur. There is dense patch of fur on the wing located on the top back
third of the forearm and propatgial membrane. There is also a second patch of fur on the
bottom back three-quarters of the forearm that extends across the patagium near the wrist
to the base of the fourth metacarpal. These patches are darker in color than the membrane
and are visible to the naked eye (Simmons and Voss 1998). The dental formula is I 1/2, C
1/1, P 1/2, M 3/3 (Redford and Eisenberg 1992). The lateral lower incisor is present
(Simmons and Voss 1998). Molossops abrasus have a “broad face, widely separated ears,
no development of wrinkles on the lips, thickish dentaries, no anterior palatal
emargination, and lacks basispheniod pits” (Norwak 1991). There is also no nose leaf
present. They also display sexual dimorphism. The average total length is 121.1 mm and
the average head body length is 82.9 mm with an average tail length is 37.6 mm (Redford
and Eisenberg 1992). The forearm length in males is 44.2-49.0 mm and in females it is
41.0-450 mm. The greatest skull length is 19.5-24.3 mm in males and 18.4-21.5 mm in
females. The width of the zygomatic arch in males is 13.7-16.5 mm and in females it is
12.7-14.3 mm. The width of the mastoid in males ranges from 12.9 to 16.2 mm and in
females it ranges from 12.7 to 14.4 mm. In males the width of the lacrimal is 9.8 to 11.0
mm and in females it is 8.17 to 9.0 mm. The length of the maxillary row in males is 7.48.8 mm and in females it is 6.8-7.85 mm and the width across the molars is 9.3-10.17 mm
in males and 8.5-9.6 mm in females (Simmons and Voss 1998).
Distribution
Molossops abrasus is found in southern Venezuela to the northern part of Argentina
(Redford and Eisenberg 1992). Paraguay is in the southern part of its range. In a paper by
Hector Arita, Molossops abrasus was classified as rare but widely distributed.
Ontogeny and Reproduction
In the Family Molossidae, the bats typically have one young per litter and only one litter
per year. Breeding typically takes place in late winter or early spring right before
ovulation (Norwak 1991).
Ecology and Behavior
Molossops abrasus is an insectivore that prefers to forage in an open habitat, along edges,
and along streams. In Paraguay they are found in Neembucu and in Campos Cerrados.
Neembucu has extensive seasonally inundated wetlands and wide grasslands in a low flat
terrain. Mixed in are palm savannas and Chaco-like forest. The Campos Cerrados is a
savanna with patches of dense forests, xerophytic forest, and grasslands that a gentle
rolling topography (Willig et al. 2000).
These bats remain active though out the year. They typically fly fast and in a straight
path. While in flight they have their mouths open to echolocate. They typically feed on
hard-shelled insects (Norwak 1991). They will form colonies that contain up to seventyfive individuals (Redford and Eisenberg 1992). They will roost in decayed logs or hollow
trees, or under bark. They tend to pick areas that are relatively warm for roosting
(Norwak 1991, Redford and Eisenberg 1992). There is a strong musky odor associated
with their roost sites (Norwak 1991).
Literature Cited
Arita, H.T., Rarity in Neotropical Bats: Correlations with Phylogeny, Diet, and Body.
Ecological Applications, Vol. 3, No. 3, Aug. 1993. Pgs 506-517.
Norwak, R.M., Walker’s Mammals of the World Volume 1 Fifth Edition. The John
Hopkins University Press 1991. Pgs 376-382.
Peters, S.L., B.K. Lim, and M.D. Engstrom. Systematics of Dog-Faced Bats (Cynomops)
Based on Molecular and Morphometric Data. Journal of Mammalogy Vol. 83,
No.4, 2003. Pgs 1097-1110.
Redford, K.H. and J.F. Eisenberg. Mammals of the Neotropics: The Southern Cone Vol.2
Chile, Argentina, Uruguay, Paraguay. The University of Chicago Press 1992. Pgs
118-119.
Simmons N.B. and R.S. Voss, The Mammals of Paracou, French Guiana: A Neotropical
Lowland Rainforest Fauna Part 1. Bats, Bulletin of the American Museum of
Natural History, No.237 New York, 1998.
Willig, M.R., S.J. Presley, R.D. Owen, and C. Lopez-Gonzalez. Composition and
Structure of Bat Assemblages in Paraguay: A Subtropical-Temperate Interface.
Journal of Mammalogy Vol. 81, No. 2, 2000. Pgs 386-401.
Reference written by Christopher Luddington, Biology 378 (Mammalogy), University of
Wisconsin – Stevens Point. Edited by Christopher Yahnke. Page last updated August 8,
2005.