Ka Ying Vang
Molossops planirostris
Southern Dog-faced Bat
Description
Molossops planarostris or Cynomops planirorstris commonly known as southern dogfaced bat are among the smallest of the free-tailed bats in Central and South America
(Reid 1997) with a wing span of about 240 millimeters and weighs about 8 grams
(Vaughan 2000). All the bats in the family Molossidae have a tail that extends well
beyond the uropatagium. The upper part of the body is reddish brown to a dark brown.
The belly part of this species is white with gray to brown along the side (Reid, 1997).
They have very short fur, about 2 to 3 millimeters long. The ears are separate and
pointed. They have two lower incisors and larger upper front teeth (Peters, 2001). There
are sensory hairs along the outer edges of the first and fifth toes (Vaughan 2000).
Geographic Range
M. planirostris is found from central Panama to Peru and as far south as northern
Argentina. Within the geographic range, there are altitudinal ranges to which M.
planarostris limit their activities. Most M. planarostris are found from lowland area to a
range of 700 meters above sea level (Reid, 1997). According to Willig et al. (2000),
“[The] distributions of many species are restricted to coastal deciduous forest, scrub
forest, or savannas.”
Ontogeny and Reproduction
Generally bats don’t have many offspring. Typically, bats have 1-2 young in each birth
period.
Ecology and Behavior
M. planarostris occupy a wide variety of warm habitat. Habitats for this bat species
range from evergreen to deciduous forest and from savannahs to swamps. M. planarostris
seem to prefer wet swampy area compared other habitat types. This species lives in
buildings, rotting logs, fence posts, and in hollow trees (Reid, 1997). Bats in the family
Molossidae tend to live in large communities (Sanderson), but M. planarostris lives alone
or in groups ranging from 2 to 8. Occasionally, there are groups that can number up in
the hundreds (Reid, 1997). Unlike other bats that produce sound from their voice box, M.
planarostris produce sound by clicking their tongue (Fenton, 1983).
Their long and narrow wings suggest that they fly long distances when foraging for food.
Their wings morphology does not allow them to fly within dense forest. Most of their
flying is in open space and at canopy level (Peters, 2001). Also with its long and pointed
wings, this species can produce great power as well as great maneuverability
(Sanderson). Even though their wings design gives them power and agility, it comes with
a trade of. In order for them to take flight, they must attain high speed at first. To attain
such speed, they nest in high cliffs, building or trees and dive down. Just before hitting
the ground their winds allow them to maneuver upward and achieve level flight. M.
planarostris are the few bats that cannot take to flight while on the ground (Sanderson).
Since they cannot take to flight on the ground, M. planarostris can pack away their wings
and run about on all four limbs to escape from predator or to get to higher ground
(Sanderson).
Remarks
Population Status: G5 – “Apparently secure- Uncommon but not rare; some cause for
long-term concern due to decline or other factors” (Nature Server Org.).
Literature Cited
Fenton, M. Brock. Just Bats. Toronto, Buffalo, London. University of Toronto, 1983.
InfoNature: Bird, mammal, and amphibians or Latin America. 2004. Version 3.2.
Arlington, Virginia (USA): NatureServe.
<http://www.natureserve.org/infonatura>
Peters, Sandra L., Lim, Burton K., Engstrom, Mark D. “Systematics of Dog-Faced Bats
(Cynomops) Based on Molecular and Morphometric Data.” Journal of
Mammalogy 83 (2001): 1097-1110.
Reid, Fiona A. A Field Guide to the Mammals of Central American & Southeast Mexico.
Oxford. Oxford University Press. 1997.
Sanderson, Ivan T. Living Mammals of the World. New York. Hanover House.
Vaughan, Terry A., Ryan, James M., Czaplewski, Nicholas J. Mammalogy. New York.
Saunders College Publishing. 2000.
Willig, Michael R., et al. “Composition and Structure of Bat Assemblages in Paraguay: A
Subtropical-Temperature Interface.” Journal of Mammalogy 81 (2000): 386-406.
Reference written by Ka Ying Vang, Biology 378 (Mammalogy), University of Wisconsin
– Stevens Point. Edited by Christopher Yahnke. Page last updated August 8, 2005.