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

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of phyllostomid

bat Bats are flying mammals of the order Chiroptera (). 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 birds, flying with their very long spread-out ...

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 de ...

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, and Rhinolophidae families. Because these bats Animal echolocation, echolocate nasally, this nose-leaf is thought to serve a role ...

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, wher ...

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 that is 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 ...

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, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, from

Pernambuco Pernambuco ( , , ) is a States of Brazil, state of Brazil located in the Northeast Region, Brazil, Northeast region of the country. With an estimated population of 9.5 million people as of 2024, it is the List of Brazilian states by population, ...

to Parana, and inland to Goias and

Mato Grosso do Sul Mato Grosso do Sul ( ) is one of Federative units of Brazil, Brazil's 27 federal units, located in the southern part of the Central-West Region, Brazil, Central-West Region, bordering five Brazilian states: Mato Grosso (to the north), Goiás and ...

. Previously thought to be

endemic Endemism is the state of a species being found only 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 foun ...

to Brazil, it has also been found in eastern

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

. There are no subspecies. While it may prefer

tropical rainforest Tropical rainforests are dense and warm rainforests with high rainfall typically found between 10° north and south of the Equator. They are a subset of the tropical forest biome that occurs roughly within the 28° latitudes (in the torrid zo ...

, 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, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

Diet and behaviour

The Brazilian big-eyed bat is

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

, and at its most active after midnight. It is

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

and highly specialised for eating

fig The fig is the edible fruit of ''Ficus carica'', a species of tree or shrub in the flowering plant family Moraceae, native to the Mediterranean region, together with western and southern Asia. It has been cultivated since ancient times and i ...

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, 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