The Ipanema bat (''Pygoderma bilabiatum'') is a
bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...
species of order
Chiroptera and family Phyllostomidae. It is found in northern
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
,
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
, southeastern
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
and
Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
.
It is
the only species within its genus.
Description
The Ipanema bat is a medium-sized
bat
Bats are mammals of the order Chiroptera.''cheir'', "hand" and πτερόν''pteron'', "wing". With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most bi ...
which is brown-furred overall, with the exception of its white-furred shoulders.
[Webster, W.D. and R. Owen. 1984. Pygoderma bilabiatum. Mammalian Species, 220: 1-3.] The fur of its back is a darker shade of brown than that of its chest.
It has less fur on its shoulders and upper chest than on the rest of its body, particularly in males.
[Myers, P. 1981. Observations on Pygoderma bilabiatum (Wagner). Z. SAUGETIERKD, 46(3): 146-151.] Its
rostrum is shorter and more square-shaped than other species of its subfamily,
Stenodermatinae
Stenodermatinae is a large subfamily of bats in the family Phyllostomidae.
List of species
Subfamily Stenodermatinae
*Genus: ''Ametrida''
**Little white-shouldered bat, ''Ametrida centurio''
*Genus: ''Ardops''
**Tree bat, ''Ardops nichollsi''
*G ...
[Tavares, V. D. C. and A. Tejedor. 2009.The forelimb swellings of Pygoderma bilabiatum (Chiroptera: Phyllostomidae). Chiroptera Neotropical, 15(1): 411-416.] It has a large nose and no tail, with roundish ears having a small, 4–5 mm (0.16-0.2 in)
tragus.
Size varies based on sex and geographical location. Females tend to be larger than males.
[Owen, R.D. and W.D. Webster. 1983. Morphological variation in the Ipanema bat, Pygoderma bilabiatum, with description of a new subspecies. Journal of Mammalogy, 64:146-149.] The skulls of Ipanema bats from Argentina and Bolivia are bigger than those of their counterparts in Paraguay and Brazil.
''P. bilabiatum'' typically has two molars.
[Dick, C. 2002. Variation in the Dental Formula of the Ipanema Bat, Pygoderma bilabiatum. The Southwestern Naturalist, 47(3): 505-508.] However, some females have a third molar (usually in the mandibular jaw) not seen in males.
This may be correlated with the larger jaw size of females.
While both males and females have glands below the jaw and surrounding the eyes, the glands in males are generally larger.
Males also have
forelimb
A forelimb or front limb is one of the paired articulated appendages (limbs) attached on the cranial ( anterior) end of a terrestrial tetrapod vertebrate's torso. With reference to quadrupeds, the term foreleg or front leg is often used instead. ...
swellings, which are not seen in females.
The size and presence of such swellings varies geographically.
Additionally, forelimb swellings appear to be correlated with development of the males' eye glands.
Due to the
dimorphism
Dimorphism or dimorphic may refer to:
Science
* Dimorphic root systems, plant roots with two distinctive forms for two separate functions
* Sexual dimorphism, a phenotypic difference between males and females of the same species
* Nuclear dimorph ...
of forelimb swellings, It is thought that they could be correlated with
mating behaviors.
Range and habitat
The Ipanema bat resides in northern Argentina, southeastern Brazil, Paraguay, and Bolivia.
[Esbérard, C. E. L., I. P. de Lima, P. H. Nobre, S. L. Althoff, T. Jordão-Nogueira, D. Dias, F. Carvalho, M.E. Fabián, M.L. Sekiama, and A.S. Sobrinho. 2011. Evidence of vertical migration in the Ipanema bat Pygoderma bilabiatum (Chiroptera: Phyllostomidae: Stenodermatinae). Zoologia (Curitiba), 28(6): 717-724.] Their preferred habitats are
tropical forests
Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds.
Some tropical fores ...
, subtropical forests, and
secondary forests
A secondary forest (or second-growth forest) is a forest or woodland area which has re-grown after a timber harvest or clearing for agriculture, until a long enough period has passed so that the effects of the disturbance are no longer evident. ...
.
[Oprea, M., P. Mendes, T. Vieira, V. Pimenta, D. Brito, and A. Ditchfield. 2007. Mammalia, Chiroptera, Phyllostomidae, Phyllostomus hastatus and Pygoderma bilabiatum: first occurrence in the Brazilian coastal shrubland ecosystem. Check List, 3(3): 175-179.] Although atypical, they are sometimes found in the coastal
shrublands of Brazil.
This suggests that perhaps ''P. bilabiatum'' can expand its habitat into dryer, more sparsely vegetated areas.
Biology
''P. bilabiatum'' is
frugivorous
A frugivore is an animal that thrives mostly on raw fruits or succulent fruit-like produce of plants such as roots, shoots, nuts and seeds. Approximately 20% of mammalian herbivores eat fruit. Frugivores are highly dependent on the abundance and ...
, specializing in fruit that is easily digested.
These fruits are usually very ripe and fleshy, with few seeds.
The fruit choices of the Ipanema bat are diverse, including the fruits of ''
Lucuma caimito'', ''
Miconia
''Miconia'' is a genus of flowering plants in the glory bush family, Melastomataceae, native to warm temperate to tropical regions of the Americas. The species are mostly shrubs and small to medium-sized trees up to 15 m tall. The generic name ...
brasiliensis'', and trees of the genus ''
Celtis'', as well as ''
Maclura tinctoria
''Maclura tinctoria'', known as old fustic and dyer's mulberry, is a medium to large tree of the Neotropics, from Mexico to Argentina. It produces a yellow dye called fustic primarily known for coloring khaki fabric for U.S. military apparel du ...
'', ''
Solanum granuloso-leprosum'', and ''
Ficus
''Ficus'' ( or ) is a genus of about 850 species of woody trees, shrubs, vines, epiphytes and hemiepiphytes in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending in ...
enormis''.
[Cáceres, N. C. and M.O. Moura. 2003, Fruit removal of a wild tomato, Solanum granulosoleprosum Dunal (Solanaceae), by birds, bats and non-flying mammals in an urban Brazilian environment. Revista Brasileira de Zoologia, 20(3): 519-522.][Farias, D. 2014. Reports on the diet and reproduction of the Ipanema fruit bat, Pygoderma bilabiatum in a Brazilian forest fragment. Chiroptera Neotropical, 3(1): 65-66.] Some may also feed on nectar.
''P. bilabiatum'' usually reproduces in either the fall or the winter.
It is thought that they give birth during the later end of the dry period and wean their young at the beginning of the wet period.
This strategy coordinates birth with the highest amount of fruit attainability.
Females only carry one fetus at a time.
Behavior
Migration patterns may be influenced by rainfall amount and/or temperature. ''P. biliabatum'' appears to prefer regions with a minimum annual rainfall of 1500 mm (59 in) and moderate temperatures of 16-23 °C (61-73 °F)
Food availability and foraging capabilities seem to be an important factor in the timing and distance traveled during migration
Females and males migrate differently.
Males tend to linger in lower elevations, while females reside at intermediate and high elevations.
References
{{Taxonbar, from=Q94808
Phyllostomidae
Bats of South America
Bats of Brazil
Mammals of Argentina
Mammals of Bolivia
Mammals of Paraguay
Fauna of the Atlantic Forest
Mammals described in 1843
Taxa named by Johann Andreas Wagner