Eumops dabbeneibig bonneted bat

Geographic Range

Individuals of E. dabbenei have been found in Columbia (Magdalena River Valley), northern Venezuela, central Paraguay, and northern Argentina (Chaco Province).

These bats tend to be rare throughout their range, and they are poorly known relative to most other Eumops species. (Nowak 1999; Harrison et al. 1979)


E. dabbenei tends to roost in the holes of trees and in buildings in neotropic areas. The areas of Columbia, Venezuela, Paraguay, and Argentina where they are found tend to be forested, but the full range of habitats available to E. dabbenei is poorly understood.

(Barquez et al. 1993; Novak 1999; Fioramonti 2001)

Physical Description

Large ears connected across the head at their base. Ears are smaller than in the related species, and members of this species have a pointed tragus. The skull is massive, with shallower basisphenoid pits than E. perotis. A large gular (throat) sac is present in males, which swells during mating season. The lamboid crests are strongly developed, while the sagittal crest is less developed. The thumb pad is triangular. The lips are smooth and the tail is quite thick. The dental formula is 1/2, 1/1, 2/2, 3/3 = 30. The dorsal coloration is chestnut, with a paler ventral coloration.

This species is large compared to most members of Eumops, a fact which causes it to become confused with E. perotis. The pointed ears mentioned above are an important distinguising feature.

(Barquez et al. 1993; Novak 1999)

  • Average mass
    76 g
    2.68 oz
  • Average length
    165 mm
    6.50 in


The reproductive and social behavior of this species has not been examined.

Like some other members of the Eumops genus, E. dabbenei males have a throat sac that swells with a phermone-laden musk during the breeding season. Females tend to have one litter per year, although it is possible for them to have two. (Novak 1999; Hill & Smith 1984)

  • Average number of offspring


Communication and Perception

Food Habits

These bats feed by catching insects in flight; this behavior is known as "aerial insectivory". There is evidence that fat metabolism is of primary importance to this species, as opposed to protein or carbohydrate metabolism.

(Findley 1993)
  • Animal Foods
  • insects

Ecosystem Roles

This species is a secondary or tertiary consumer, meaning that it eats either herbivores or carnivores that prey on herbivores; these prey item are primarily airborne insects. (Findley 1993)

Conservation Status

The abundance of this species is poorly understood, but is believed to be rare throughout its range. It does not have specially protected status at this time (Barquez et al. 1993).


Mark Nabong (author), University of Michigan-Ann Arbor, Kate Teeter (editor), University of Michigan-Ann Arbor.



living in the southern part of the New World. In other words, Central and South America.

World Map


young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.


an animal that mainly eats meat


uses smells or other chemicals to communicate


used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.


animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.


union of egg and spermatozoan


forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.


An animal that eats mainly insects or spiders.

internal fertilization

fertilization takes place within the female's body


having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.


active during the night


rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season


reproduction that includes combining the genetic contribution of two individuals, a male and a female


uses touch to communicate


the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.


reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.


Barquez, R., N. Giannini, M. Mares. 1993. Guide to the Bats of Argentina / Guia de los Murcielagos de Argentina. Norman: Oklahoma Museum of Natural History.

Findley, J. 1993. Bats: A Community Perspective. Cambridge: Cambridge University Press.

Fioramonti, E. "Museo de la Provincia de Santa Fe (Argentina)" (On-line). Accessed October 10,2001 at

Harrison, D., N. Pendleton, G. Harrison. 1979. Eumops dabbenei Thomas 1914 (Chiroptera: Molossidae), a free-tailed bat new to the fauna of Paraguay. Mammalia, 43(2): 251-252.

Hill, J., J. Smith. 1984. Bats: A Natural History. London: British Museum (Natural History).

Nowak, R. 1999. Walker's Mammals of the World. Baltimore, MD: The Johns Hopkins University Press.