Davy's (lesser) naked-backed bat (''Pteronotus davyi'') is a small, insect-eating, cave-dwelling
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 ...
of the Family
Mormoopidae
The family Mormoopidae contains bats known generally as mustached bats, ghost-faced bats, and naked-backed bats. They are found in the Americas from the Southwestern United States to Southeastern Brazil.
They are distinguished by the presen ...
. It is found throughout
South
South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both west and east.
Etymology
The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...
and
Central America
Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...
, including
Trinidad
Trinidad is the larger, more populous island of the Republic of Trinidad and Tobago, the country. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is the southernmost island in ...
, but not
Tobago
Tobago, officially the Ward of Tobago, is an List of islands of Trinidad and Tobago, island and Regions and municipalities of Trinidad and Tobago, ward within the Republic of Trinidad and Tobago. It is located northeast of the larger islan ...
,
Guyana
Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...
,
Suriname
Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...
, or
French Guiana
French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...
.
[Adams, J.K. (1989) ''Pteronotus davyi''. Mammalian Species 346: 1-5] Specimens of this bat had been found infected with
rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. It was historically referred to as hydrophobia ("fear of water") because its victims panic when offered liquids to drink. Early symptoms can include fever and abn ...
in Trinidad during the height of that island's vampire-bat-transmitted rabies epidemic of the early half of the 20th century, but not in recent times.
Description
General features
The lesser naked-backed bat (also known as Davy's naked-backed bat) earns its name from the appearance of its backside. The bat species appears to have a hairless or "naked" back due to the attachment of its wings on the mid-line of its dorsal surface.
The wing membranes give the bat's back its shiny appearance. The lesser-naked backed bat shares this diagnostic feature with two other species of bat of the same family (Mormoopidae,) named ''Pteronotus fulvus'' and ''Pteronotus gymnonotus''. ''Pteronotus dayvi'' is easily distinguishable from other species in the Genus Pteronotus by sparsely distributed hairs on the membranes of its wings.
''P. dayvi'' is characterized by very dense pelage that changes color throughout the seasons.
Little sexual dimorphism is observed in this species, except within the most northern populations located in Sonora. Males of this population are observed to be significantly larger than females.
The wing aspect ratio of this species is very high in comparison to many Microchiroptera, allowing these bats to fly long distances at fast speeds. The lips of these bats are large, perhaps allowing for focusing of the soundwaves that are emitted from their pharynx during echolocation.
Behavior
''Pteronotus davyi'' are nocturnal, insectivorous bats that tend to roost in communities within their own species. Daytime roosts are seen to be shared between other species within the family Mormoopidae.
This species uses echolocation to target prey in the dark, deciduous forests they reside in. Insects preyed upon include moths, flies and earwigs.
''Pteronotus davyi'' are known to be seasonally monogamous, and usually mate in the months of January and February.
These bats have one offspring per mating season. The birth of the offspring occurs during the rainy season. The rainy season provides a surge in the insect population, which proves to be important for these insectivorous bats, allowing the young to mature at a fast rate.
Due to their high wing-aspect ratio, these bats can fly at quick burst speeds for long distances, although their long wingspan inhibits them from having great agility.
They are also sufficient climbers. It is believed that they climb high to the top of their roost in order to quickly fly away from the entrance and avoid any nearby predators.
During nighttime foraging for insects, flight usually occurs near the ground.
Although predation has not been intensely observed in this species, researchers have found that ''P. davyi'' has been hunted by
American kestrel
The American kestrel (''Falco sparverius'') is the smallest and most common falcon in North America. Though it has been called the American sparrowhawk, this common name is a misnomer; the American kestrel is a true falcon, while neither th ...
s (''Falco sparverius'') a very common North American falcon. These falcons have been seen to hide at the entrance of the bat roosts and dive after the bats as they are exiting the cave.
Ecology and distribution
These bats are found most commonly in moist habitats that sustain a high volume of insects. Nighttime roosts of these animals are most commonly found in warm, dark, moist caves. ''P. davyi'' are found as far north as Mexico and as far south as South America and Honduras.
They typically prefer low elevations, but some individuals have been observed at elevations as high as 2,000 meters above sea level.
There has been no recorded observance of this species in
Guyana
Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...
,
Suriname
Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...
, or
French Guiana
French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...
.
Studies of this species have revealed genetic divergence between the Southeastern ''P. davyi'' population, and the Pacific and Gulf Coast populations.
This is believed to be a result of geographical barriers that separate these populations. These geographical barriers are
Sierra Madre Occidental
The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American C ...
,
Sierra Madre Oriental
The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that ...
, and
Sierra Madre del Sur
The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca.
Geography
The Sierra Madre del Sur joins with the Eje Volcánico Transv ...
.
References
External links
Pteronotus
{{Taxonbar, from=Q1834816
Pteronotus
Bats of Central America
Bats of South America
Bats of the Caribbean
Bats of Brazil
Bats of Mexico
Mammals of Colombia
Mammals of French Guiana
Mammals of Guyana
Mammals of Peru
Mammals of Suriname
Mammals of Trinidad and Tobago
Mammals of Venezuela
Mammals described in 1838
Taxa named by John Edward Gray
Fauna of the Sierra Madre Oriental
Fauna of the Sierra Madre del Sur