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)
Biogeographic Regions: neotropical (Native )
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.
(Barquez et al. 1993; Novak 1999)
Average mass: 76 g.
Average length: 165 mm.
Other Physical Features: endothermic ; bilateral symmetry
Habitat and Ecology
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)
Habitat Regions: tropical
Terrestrial Biomes: forest ; rainforest ; scrub forest
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.
Animal Foods: insects
Primary Diet: carnivore (Insectivore )
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)
Known prey organisms
Life History and Behavior
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: 1.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Parental Investment: altricial
IUCN Red List Assessment
Red List Category
Red List Criteria
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).
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Big bonneted bat
The big bonneted bat, or Dabbene's mastiff bat (Eumops dabbenei) is a species of bat in the family Molossidae, native to South America. It is named for a former conservator at the Buenos Aires National Museum.
The big bonneted bat is a relatively large bat species, with adults measuring about 19 cm (7.5 in) in length, and weighing 100 g (3.5 oz). The tail is thick, and measures about 6 cm (2.4 in) in length. The fur is chestnut or pale grey, and lighter on the animal's underparts. The ears are broad and relatively short, and join together at their base in the centre of the forehead. Compared with other nearby species of bonneted bat, they have a larger body, a short, wide snout, short ears, and nostrils that do not form a tube. As in other bonneted bats, the males possess a gland on the throat that secretes a liquid that stains and mats the surrounding fur.
Distribution and habitat
Big bonneted bats are known from two distinct parts of South America. A northern population is known from Venezuela and Colombia, while a southern population has been identified in Bolivia, Paraguay, and northern Argentina. There are no recognised subspecies, and it is possible that the bat inhabits, but has not yet been identified from the regions of eastern Brazil that lie between those of the two known populations. It is known to inhabit areas of low vegetation interspersed with patches of tropical forest, at elevations of up to 1,100 m (3,600 ft).
Big bonneted bats are insectivorous, and roost in hollow trees and artificial structures such as houses. They have been reported to emit audible "piercing shrieks" when they are foraging for food. Little is known about their reproduction, although juveniles have been observed in December and January.