Tricolored bat | |
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A tricolored bat captured near Arnold Air Force Base in 2022 | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Chiroptera |
Family: | Vespertilionidae |
Tribe: | Perimyotini |
Genus: | Perimyotis Menu, 1984 |
Species: | P. subflavus |
Binomial name | |
Perimyotis subflavus (F. Cuvier, 1832) | |
Range of tricolored bat (in yellow) | |
Synonyms | |
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The tricolored bat (Perimyotis subflavus) or American perimyotis [2] is a species of microbat native to eastern North America. Formerly known as the eastern pipistrelle, based on the incorrect belief that it was closely related to European Pipistrellus species, the closest known relative of the tricolored bat is now recognized as the canyon bat. Its common name "tricolored bat" derives from the coloration of the hairs on its back, which have three distinct color bands. It is the smallest bat species in the eastern and midwestern US, with individuals weighing only 4.6–7.9 g (0.16–0.28 oz). This species mates in the fall before hibernation, though due to sperm storage, females do not become pregnant until the spring. Young are born helpless, though rapidly develop, flying and foraging for themselves by four weeks old. It has a relatively long lifespan, and can live nearly fifteen years.
In the summer, females roost in small groups and males roost solitarily in tree foliage or beard lichen. [3] It eats a diverse array of insects, foraging with a slow, erratic flight and navigating via echolocation. Though once considered one of the most common bat species in its range, its populations have declined rapidly since 2006 with the introduction of the fungal disease white-nose syndrome. It was listed as an endangered species in 2012 in Canada, and has been petitioned for inclusion on the US endangered species list. Along with the silver-haired bat, the tricolored bat is one of two bat species whose rabies variants have most frequently been implicated in human rabies deaths in the US, with sixteen deaths from 1958–2000.
The tricolored bat was described as a new species in 1832 by French zoologist Frédéric Cuvier, who placed it in the genus Vespertilio with a scientific name of Vespertilio subflavus. The holotype had been collected in the US state of Georgia by American naturalist John Eatton Le Conte. [4] In 1897, American zoologist Gerrit Smith Miller Jr. placed it in the genus Pipistrellus for the first time as a result of its physical similarities to other members of the genus. [5] Its common name was thus the "eastern pipistrelle". [6] In 1984 its status was reviewed, with H. Menu concluding that it was more similar in appearance to species in the genus Myotis rather than Pipistrellus, erecting a new genus for the taxon: Perimyotis. The name "Perimyotis" means "around Myotis", alluding to its similarities with the genus. [7] This classification was not immediately accepted, however, with a 1985 study instead grouping it and the canyon bat into the genus Parastrellus and a 1987 publication maintaining that the tricolored bat was part of the Pipistrellus genus, though they listed Perimyotis as one of seven subgenera. However, in 2003, a genetic study concluded that the tricolored bat was distinct from Pipistrellus species (and the canyon bat), confirming the validity of the genus Perimyotis. [8] Usage of the scientific name Perimyotis subflavus is widely accepted as of 2019. [9] [10] [1] Its common name was changed from "eastern pipistrelle" to "tricolored bat" to reflect its revised classification. [6]
A 2010 study found that the sister taxon of the tricolored bat is the canyon bat, with the authors suggesting that these two genera form a tribe, though declining to name and formally describe the tribe. Instead, they referred to it as the "perimyotine group", which they gave as the most basal member of a clade that also included the following tribes: Nycticeiini, Eptesicini, Vespertilioni, and another unnamed tribe referred to as the "hysugine group" (including Chalinolobus , Hypsugo , Laephotis , Neoromicia , Nycticeinops , Tylonycteris , and Vespadelus ). [11] The tribe was later described as Perimyotini. [12]
Its species name "subflavus" means "a little less than yellow", meaning yellowish or pale yellow. [13] Four subspecies are recognized: [9]
The tricolored bat has blond fur that is distinctly tricolored on its back. Individual hairs tricolored: dark gray at the base, buffy (yellowish brown) in the middle, and brown or reddish brown at the tip. [13] It is the smallest bat species found in the eastern and midwestern US. [14] Individuals have a forearm length of 31.4–34.1 mm (1.24–1.34 in) and weigh 4.6–7.9 g (0.16–0.28 oz). [15] Its forearms are reddish, contrasting sharply with the black membranes of its wings. [16] Its wingspan is 21–26 cm (8.3–10.2 in). [17] It has a dental formula of 2.1.2.33.1.2.3 for a total of 34 teeth. [15]
The tricolored bat is a seasonal breeder, with copulation (mating) occurring in the fall before hibernation. Ovulation does not occur until the spring, however, and females store the males' sperm in their uteruses through the winter. Gestation (pregnancy) length is about forty-four days, with females giving birth in June or July. The litter size is typically two individuals. As newborns, the combined mass of twin pups can be as great as 58% of the mother's postpartum mass. At birth, the young lack fur and their eyes are closed. [15] The mother leaves the offspring behind at the roost while she forages at night. [17] Offspring develop rapidly, beginning to fly at three weeks old. By four weeks old, they are foraging for themselves. [15] Young do not reach sexual maturity in their first fall; they do not breed until their second fall. [17]
Individuals can live at least 14.8 years in the wild; juveniles have higher mortality rates than adults, and females have higher mortality rates than males. [15]
During the summer, the tricolored bat will roost in tree foliage or buildings, with females alone or in maternity colonies of up to thirty individuals. [17] [18] Trees used for this purpose include oak, maple, the eastern cottonwood, and American tulip tree. [19] Males are solitary and do not form colonies. [18] In Nova Scotia, researchers discovered nearly one hundred roosts of this species, finding that all sampled individuals were roosting not in tree foliage, but rather in a species of beard lichen, Usnea trichodea . This was thought to be the first documentation of a bat using beard lichen as a roosting substrate. It was speculated that the tricolored bat may use the lichen to ward off parasites. Usnic acid, which has anti-insect and anti-bacterial properties, naturally occurs in beard lichens, and no ectoparasites (external parasites) have been documented on the tricolored bat in Nova Scotia. [20]
In the winter, the tricolored bat hibernates in mines, caves, or other human structures. A years-long study of a mine in the US state of Nebraska found that in the summer, the mine was mostly occupied by males. Total number of tricolored bats using the mine at one time ranged from zero to forty-three. Bats were in a state of torpor from November to April. More bats used the mine as a roost in the winter than in the summer. [21] In another abandoned mine in the US state of Indiana, researchers found that the tricolored bat roosts solitarily during hibernation for the majority of the time (96.8% of observations were singletons). During hibernation, males lose an average of 2.65 g (0.093 oz), while females lose an average of 2.5 g (0.088 oz). [22]
The tricolored bat is insectivorous, consuming small prey of 4–10 mm (0.16–0.39 in) in length. Prey taxa include mosquitoes, beetles, ants, moths, and cicadas. It forages with slow, erratic flight in areas near water or forest edges. [15] It is one of the first bat species to begin foraging each night. [23] It navigates and searches for prey via echolocation (sonar). Its echolocation calls are at a high frequency; visual renderings of the calls show a distinctive hook-shaped call profile, with the lowest frequencies (bottom of the hook shape) at 42 kHz. [17]
The tricolored bat's natural predators include the northern leopard frog, birds of prey, raccoons, snakes, skunks, and prairie voles. [13] [15] Feral cats will also catch and kill them as they leave their hibernacula (cave or mine used for hibernation). [17] There are also records of it being attacked by the hoary bat. [15] [24] The tricolored bat is the host to several species of endoparasites (internal parasites) and ectoparasites. Oocysts (spores) of an Eimeria species ( Eimeria heidti ) have been recovered from its guano (feces). [25]
The tricolored bat has experienced severe population decline as a result of the fungal disease white-nose syndrome, which arrived in the US in 2006, with losses of 70% and greater detected in multiple US states. [26] The disease kills bats by colonizing their skin during the winter, causing them to arouse from torpor and burn through their limited fat reserves. Though its population experienced dramatic reduction, subsequent studies have found that their numbers may be stabilizing, though hibernacula where many individuals once roosted may only host fewer than five bats, or even one solitarily. [27]
The tricolored bat is common throughout eastern North America, with the southern extent of its range in Central America and the northern extent in southern Canada. Its range has expanded since the 1980s, with westward expansion reaching the US states of Colorado, New Mexico, South Dakota, and Wyoming. Additionally, its range started to include the Great Lakes Basin. [18]
As of 2018, it is listed as a vulnerable species by the IUCN. In 2008, however, it was considered a least-concern species, which is the IUCN's lowest conservation priority. In the time between the two assessments, the fungal disease white-nose syndrome became widespread in eastern North America, severely impacting the tricolored bat. [1] Historically, it was one of the most common bat species of eastern North America. [23] After an emergency assessment, the tricolored bat is considered an endangered species under the Committee on the Status of Endangered Wildlife in Canada as of 2012. [28] In 2016, the Center for Biological Diversity and Defenders of Wildlife submitted a petition to the United States Fish and Wildlife Service (USFWS) to list the tricolored bat under the Endangered Species Act of 1973. The USFWS determined that the petition demonstrated that listing the species as "threatened" or "endangered" may be warranted. [29] In September 2022, the USFWS announced [30] it would protect the bat as endangered under the Endangered Species Act, following a lawsuit [31] from the Center for Biological Diversity.
Along with the silver-haired bat, the tricolored bat is one of two species of bat whose rabies variants are responsible for 70% of human rabies cases from bats in the US. [32] Additionally, the rabies virus variants associated with these two species caused 75% of cryptic rabies deaths in the US (rabies cases where the exposure route is unclear, and no bite history exists). [32] From 1958–2000, sixteen people in the US died from the rabies variant associated with tricolored bats, or 46% of all nationwide indigenous (not acquired elsewhere) rabies fatalities. [32] The tricolored bat is infrequently encountered by humans and submitted for rabies testing, with only thirty-one individuals tested for rabies in the US in 2017. Of those, one (3.4%) tested positive for the virus. [33]
Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat families, specialised in many forms to occupy a range of habitats and ecological circumstances, and it is frequently observed or the subject of research. The facial features of the species are often simple, as they mainly rely on vocally emitted echolocation. The tails of the species are enclosed by the lower flight membranes between the legs. Over 300 species are distributed all over the world, on every continent except Antarctica. It owes its name to the genus Vespertilio, which takes its name from a word for bat, vespertilio, derived from the Latin term vesper meaning 'evening'; they are termed "evening bats" and were once referred to as "evening birds".
Pipistrellus is a genus of bats in the family Vespertilionidae and subfamily Vespertilioninae. The name of the genus is derived from the Italian word pipistrello, meaning "bat".
The big brown bat is a species of vesper bat distributed widely throughout North America, the Caribbean, and the northern portion of South America. It was first described as a species in 1796. Compared to other microbats, the big brown bat is relatively large, weighing 15–26 g (0.53–0.92 oz) and possessing a wingspan of 32.5–35 cm (12.8–13.8 in).
The common pipistrelle is a small pipistrelle microbat whose very large range extends across most of Europe, North Africa, South Asia, and may extend into Korea. It is one of the most common bat species in the British Isles. In Europe, the northernmost confirmed records are from southern Finland near 60°N.
The Indiana bat is a medium-sized mouse-eared bat native to North America. It lives primarily in Southern and Midwestern U.S. states and is listed as an endangered species. The Indiana bat is grey, black, or chestnut in color and is 1.2–2.0 in long and weighs 4.5–9.5 g (0.16–0.34 oz). It is similar in appearance to the more common little brown bat, but is distinguished by its feet size, toe hair length, pink lips, and a keel on the calcar.
The soprano pipistrelle is a small species of bat. It is found in Europe and often roosts on buildings.
The canyon bat, also known as the western pipistrelle, or American parastrelle is a species of vesper bat. It is found in Mexico and in the western United States. The species has historically been placed in the genus Pipistrellus, but molecular evidence does not show any close relationship with that genus, and accordingly it was classified into its own genus, Parastrellus, in 2006.
The western false pipistrelle, species Falsistrellus mackenziei, is a vespertilionid bat that occurs in Southwest Australia. The population is declining due to loss of its habitat, old growth in tall eucalypt forest which has largely been clear felled for tree plantations, wheat cultivation and urbanisation. Although it is one of the largest Australian bats of the family, the species was not recorded or described until the early 1960s. A darkly colored bat with reddish brown fur and prominent ears, they fly rapidly around the upper canopy of trees in pursuit of flying insects.
The big-eared pipistrelle is a species of vesper bat in the family Vespertilionidae. It can be found in Indonesia and Malaysia. It forages over mud flats over Peninsula Malaysia but its roosting activities are unknown. Its habitat is being threatened by deforestation for agriculture, plantations, logging and fires but how it affects this bat or if it is adaptable are unknown.
The silver-haired bat is a solitary migratory species of vesper bat in the family Vespertilionidae and the only member of the genus Lasionycteris.
The eastern small-footed bat is a species of vesper bat. It can be found in southern Ontario and Quebec in Canada and in mountainous portions of the eastern United States from New England to northern Georgia, and westward to northern Arkansas. It is among the smallest bats in eastern North America and is known for its small feet and black face-mask. Until recently, all North American small-footed Myotis were considered to be "Myotis leibii". The western population is now considered to be a separate species, Myotis ciliolabrum. The Eastern small-footed bat is rare throughout its range, although the species may be locally abundant where suitable habitat exists. Studies suggest white-nose syndrome has caused declines in their populations. However, most occurrences of this species have only been counted within the past decade or two and are not revisited regularly, making their population status difficult to assess. Additionally, most bat populations in the Eastern U.S. have been monitored using surveys conducted in caves and mines in the winter, but Eastern small-footed bats hibernate in places that make them unlikely to be encountered during these surveys. Perhaps as a result, the numbers of Eastern small-footed bats counted in winter tend to be low and they are relatively variable compared to other species of bats. Many biologists believe the species is stable, having declined little in recent times, but that it is vulnerable due to its relatively restricted geographic range and habitat needs.
The southern forest bat is a vesper bat found in Australia.
The Vespertilioninae are a subfamily of vesper bats from the family Vespertilionidae.
The little brown bat or little brown myotis is an endangered species of mouse-eared microbat found in North America. It has a small body size and glossy brown fur. It is similar in appearance to several other mouse-eared bats, including the Indiana bat, northern long-eared bat, and Arizona myotis, to which it is closely related. Despite its name, the little brown bat is not closely related to the big brown bat, which belongs to a different genus.
The Christmas Island pipistrelle is an extinct species of vesper bat that was found only on Christmas Island, Australia.The last individual bat was seen in August 2009 with no further sightings despite intensive efforts to locate it.
There are eighteen indigenous species of bats in Canada, which are found in many parts of the country. They are insectivores, and are prey to falcons, hawks, owls, snakes, cats, and raccoons.
Cryptic rabies refers to infection from unrecognized exposure to rabies virus. It is often phylogenetically traced to bats. It is most often seen in the southern United States. Silver-haired bats and tricolored bats are the two most common bat species associated with this form of infection, though both species are known to have less contact with humans than other bat species such as the big brown bat. That species is common throughout the United States and often roosts in buildings and homes where human contact is more likely.
A maternity colony refers to a temporary association of reproductive female bats for giving birth to, nursing, and weaning their pups. The colonies are initiated by pregnant bats. After giving birth, the colony consists of the lactating females and their offspring. After weaning, juveniles will leave the maternity colony, and the colony itself will break apart. The size of a maternity colony is highly variable by species, with some species forming colonies consisting of ten or fewer individuals, while the largest maternity colony in the world in Bracken Cave is estimated to have over 15 million bats.
Usnea trichodea, commonly known as bony beard lichen, is a pale straw-colored fruticose lichen with a pendant growth form. It grows on trees and is native to eastern North America.
The Alashanian pipistrelle is a species of bat in the family Vespertilionidae. It is found in China, South Korea, Mongolia, Japan, and Russia.