Tonatia bidens
Greater Round-eared Bat
Description
Tonatia bidens (Greater Round-eared Bat) is a medium sized bat and a member of
the family Phyllostomidae. The family Phyllostomidae includes 143 species of bats
placed in 49 genera, within the genus Tonatia there are currently seven species
recognized (Animal Diversity Web, Porter 2003). Many phyllostomids have a relatively
simple spear shaped noseleaf, also they lack postorbital processes and their premaxillae
are complete and fused to each other and to the maxillae (Animal Diversity Web).
Tonatia bidens is considered at times to be rare and little biology of the species is known
(Esberard 2004). A majority of authors recognize a single genus (Tonatia) for the roundeared bats, but several studies imply that the Tonatia bidens complex is divergent from
the other round eared bats (Porter 2003).
Distribution
Tonatia bidens occurs from southern Mexico, south to Peru, and east to northeast
Brazil (Lee 2002, Esberard 2004). Specific countries of occurrence are Argentina,
Brazil, Bolivia, Paraguay, and Peru (InfoNatura 2003). Within Paraguay Tonatia bidens
is mainly located in the west, in the Alto Chaco region (Willig 2000). In general the
genus Tonatia is a widespread, Neotropical group (Lee 2002).
Ontogeny and Reproduction
The females of Tonatia bidens have been observed pregnant in November and
nursing in May. Sub-adult bats have been observed in December, February, May, and
July (Esberard 2004).
Ecology and Behavior
Tonatia bidens is considered to be both frugivorous and insectivorous. Birds have
also been known to have been preyed upon by Tonatia bidens. Insects such as,
Orthoptera, Coleoptera, Odonata, and Lepidopteria comprise some of the bats insect diet.
Bird species that are lighter than Tonatia bidens itself were most commonly taken
(Martuscelli 1995). Tonatia bidens use themselves, hollows of trees, caves, or abandoned
houses for shelter, forming small groups (Esberard 2004, Martuscelli 1995).
Literature Cited
Esberard, Carlos and Bergallo, H.G. 2004. Aspects on the Biology of Tonatia bidens
(Spix) in the state of Rio De Janeiro, Southeast of Brazil (Mammalia, Chiroptera,
Phyllostomidae). Brazilian Journal of Zoology, 21(2).
InfoNatura. Tonatia bidens – Greater Round Eared Bat. 2003.
http://www.natureserve.org/infonatura/servlet/InfoNatura?searchName=Tonatia+
bidens.
Lee, Thomas E; Hoofer, S.R.; Van Den Bussche, R.A. 2002. Molecular Phylogenetics
and Taxonomic Revision of the Genus Tonatia (Chiroptera: Phyllostomaidae).
Journal of Mammalogy, 83(1):49-57.
Martuscelli, Paulo. 1995. Avian Predation by the Round-Eared Bat (Tonatia bidens,
Phyllostomaidae) in the Brazilian Atlantic Forest. Journal of Tropical Ecology,
11:461-464.
Porter, Calvin A; Hoofer, S.R.; Van Den Bussche, R.A; Lee, T.E. Jr.; Baker, R.J. 2003.
Systematics of Round-Eared (Tonatia and Lophostoma) Based on Nuclear and
Mitochondrial DNA Sequences. Journal of Mammalogy, 84(3): 791-808.
Willig, Michael R.; Presley, Steven J.; Owen, Robert D.; Lopez-Gonzalez, Celia. 2000.
Composition and Structure of Bat Assemblages in Paraguay: A Subtropical –
Temperate Interface. Journal of Mammalogy, 81(2): 386-401.
1999.
“Phyllostomidae” (On-line), Animal Diversity Web. Accessed October
27, 2004 at
http://animaldiversity.ummz.umich.edu/site/accounts/information/Phyllostomidae.html.
Reference written Kyle Skildum, Biology 378 (Mammalogy), University of Wisconsin –
Stevens Point. Edited by Christopher Yahnke. Page last updated August 15, 2005