The Brazilian big-eyed bat (''Chiroderma doriae'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

phyllostomid The New World leaf-nosed bats (Phyllostomidae) are found from southern North America to South America, specifically from the Southwest United States to northern Argentina. They are ecologically the most varied and diverse family within the orde ...

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 ...

from South America. The scientific name honours Italian naturalist

Giacomo Doria Marquis Giacomo Doria (1 November 1840 – 19 September 1913) was an Italian naturalist, botanist, herpetologist, and politician. He was the founder of the Museo Civico di Storia Naturale in Genoa in 1867, and director from then until his d ...

Description

The Brazilian big-eyed bat is small, with a total length of , and weighing . Like other big-eyed bats, it has a short snout, with a large cleft in the skull above the nose. The presence of this cleft gives the misleading impression that the skull lacks any

nasal bone The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose. Eac ...

s; these bones are fused with the surrounding bones, and simply do not join up in the midline, as they do in other bats. The Brazilian big-eyed bat has greyish brown fur over much of the body with greyish or dark brown underparts. There is a distinct white stripe down the middle of the back, and smaller white stripes above the eyes, stretching from the ears to the nose. The ears are rounded and relatively short, while the

nose-leaf A nose-leaf, or leaf nose, is an often large, lance-shaped nose, found in bats of the Phyllostomidae, Hipposideridae The Hipposideridae are a family of bats commonly known as the Old World leaf-nosed bats. While it has often been seen as a su ...

is pointed, with a rounded base. Compared with most of its close relatives, the Brazilian big-eyed bat has few teeth, having a dental formula of . In addition, it has spike-like upper

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, whe ...

s and large molar teeth, especially the last upper molars, and a strong

zygoma The term zygoma generally refers to the zygomatic bone, a bone of the human skull commonly referred to as the cheekbone or malar bone, but it may also refer to: * The zygomatic arch, a structure in the human skull formed primarily by parts of the z ...

that supports powerful chewing muscles. These adaptations are believed to be related to its diet, allowing it to eat hard seeds.

Distribution and habitat

The Brazilian big-eyed bat is found in eastern

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 ...

, from

Pernambuco Pernambuco () is a state of Brazil, located in the Northeast region of the country. With an estimated population of 9.6 million people as of 2020, making it seventh-most populous state of Brazil and with around 98,148 km², being the 19 ...

to Parana, and inland to Goias and

Mato Grosso do Sul Mato Grosso do Sul () is one of the Midwestern states of Brazil. Neighboring Brazilian states are (from north clockwise) Mato Grosso, Goiás, Minas Gerais, São Paulo and Paraná. It also borders the countries of Paraguay, to the southwest, and ...

. Previously thought to be

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to Brazil, it has also been found in eastern

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 ...

. There are no subspecies. While it may prefer

tropical rainforest Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as ''lowland equatori ...

, the bat is found in a range of forested environments and small wooded areas, including agricultural land and parks. When food is scarce, it may venture into urban areas, such as

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

Diet and behaviour

The Brazilian big-eyed bat is

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

, and at its most active after midnight. It is

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

and highly specialised for eating

fig The fig is the edible fruit of ''Ficus carica'', a species of small tree in the flowering plant family Moraceae. Native to the Mediterranean and western Asia, it has been cultivated since ancient times and is now widely grown throughout the world ...

s, although it may occasionally feed on other fruits or flowers. Although it is not the only species of bat to feed on figs, only it, and its close relative the

hairy big-eyed bat The hairy big-eyed bat (''Chiroderma villosum'') is a bat species from South America, South and Central America. References

Chiroderma Bats of Central America Bats of South America Bats of Brazil Mammals described in 1860 Taxa named by ...

, have been reported to chew the seeds, as well as the softer pulp, of the fruit. By doing so, they can extract more nutrition, especially protein, from the figs, allowing them to subsist primarily on this one type of fruit. Although little is known of its roosting habits, the bat does not appear to be gregarious, with groups of no more than five individuals having been reported. Few details are known of the Brazilian big-eyed bat's reproductive habits. While some studies show that breeding may occur only at certain times of the year, others have shown that it can continue year-round. Newborn young are as much as in length (almost two thirds the length of their mothers) though much lighter. Young bats are somewhat more greyish than the adults and lack the distinct facial markings, although the stripe down the back is present from birth.

References

{{Taxonbar, from=Q139351 Chiroderma Bats of South America Bats of Brazil Fauna of the Atlantic Forest Mammals described in 1891 Taxa named by Oldfield Thomas