Little brown bat | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Chiroptera |
Family: | Vespertilionidae |
Genus: | Myotis |
Species: | M. lucifugus |
Binomial name | |
Myotis lucifugus (Le Conte, 1831) | |
Subspecies | |
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Distribution of all little brown bat subspecies: M. l. lucifugus (red), M. l. pernox (green), M. l. alascensis (blue), M. l. carissima (yellow), M. l. relictus (gray) [2] | |
Synonyms | |
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The little brown bat or little brown myotis [3] (Myotis lucifugus) [1] 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.
Its mating system is polygynandrous, or promiscuous, and females give birth to one offspring annually. The offspring, called pups, are quickly weaned and reach adult size in some dimensions by three weeks old. The little brown bat has a mean lifespan of 6.5 years, though one individual in the wild reached 34 years old. It is nocturnal, foraging for its insect prey at night and roosting in hollow trees or buildings during the day, among less common roost types. It navigates and locates prey with echolocation.
It has few natural predators, but may be killed by raptors such as owls, as well as terrestrial predators such as raccoons. Other sources of mortality include diseases such as rabies and white-nose syndrome. White-nose syndrome has been a significant cause of mortality since 2006, killing over one million little brown bats by 2011. In the Northeastern United States, population loss has been extreme, with surveyed hibernacula (caves used for hibernation) averaging a population loss of 90%.
Humans frequently encounter the little brown bat due to its habit of roosting in buildings. Colonies in buildings are often considered pests because of the production of waste or the concern of rabies transmission. Little brown bats rarely test positive for rabies, however. Some people attempt to attract little brown bats to their property, but not their houses, by installing bat houses.
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Relationships of Nearctic Myotis species [4] |
The little brown bat was described as a new species in 1831 by American naturalist John Eatton Le Conte. It was initially in the genus Vespertilio , with a binomial of Vespertilio lucifugus, [5] before it was re-categorized as belonging to the Myotis genus. [6] "Myotis" is a Neo-Latin construction, from the Greek "muós (meaning "mouse") and "oûs" (meaning ear), literally translating to "mouse-eared". [7] "Lucifugus" is from Latin " lux " (meaning "light") and " fugere " (meaning "to shun"), [8] literally translating to "light-shunning". [9] The holotype had possibly been collected in Georgia near the Le Conte Plantation near Riceboro, [2] but this has been disputed because the initial record lacked detail on where the specimen was collected. [10]
Within its family, the Vespertilionidae (vesper bats), the little brown bat is a member of the subfamily Myotinae, which contains only the mouse-eared bats of genus Myotis. [6] Based on a 2007 study using mitochondrial and nuclear DNA, it is part of a Nearctic clade of mouse-eared bats. Its sister taxon is the Arizona myotis, M. occultus. [4]
As of 2005, five subspecies of the little brown bat are recognized: M. l. lucifugus, M. l. alascensis, M. l. carissima, M. l. pernox, and M. l. relictus. [11] Formerly, the Arizona myotis and southeastern myotis (M. austroriparius) were also considered subspecies (M. l. occultus and M. l. austroriparius), [2] but both are now recognized as full species. [12] [11] [13] In a 2018 study by Morales and Carstens, they concluded that the five subspecies are independent, paraphyletic lineages, meaning that grouping them together excludes other lineages with the same common ancestor, and therefore each warrant specific status. [14]
Results of one study suggested that the little brown bat can hybridize with Yuma myotis, M. yumanensis. [15] The two species occur in the same area in much of the Western United States, as well as southern British Columbia. The two species are morphologically different throughout most of the range, but in some regions, individuals have been documented that are intermediate in appearance between the two. However, a 1983 study by Herd and Fenton found no morphological, genetic, or ecological evidence to support the notion that the two species hybridize. [16]
The little brown bat is a small species, with individuals weighing 5.5–12.5 g (0.19–0.44 oz) with a total body length of 8.0–9.5 cm (3.1–3.7 in). Individuals have the lowest weight in the spring as they emerge from hibernation. It has a forearm length of 36–40 mm (1.4–1.6 in) and a wingspan of 22.2–26.9 cm (8.7–10.6 in). [17] It is a sexually dimorphic species, with females larger than males on average. [2] A variety of fur colors is possible, with pelage ranging from pale tan or reddish to dark brown. Its belly fur is a lighter color than its back fur. [17] Its fur is glossy in appearance, though less so on its belly. [2] A variety of pigmentation disorders have been documented in this species, including albinism (total lack of pigment), leucism (partial lack of pigment), and melanism (over-pigmentation). [18]
It is a diphyodont mammal, meaning that it has two sets of teeth during its lifetime—milk teeth and adult teeth. The dental formula of the milk teeth is 2.1.2.03.1.2.0 for a total of 22 teeth, while that of the adult teeth is 2.1.3.33.1.3.3 for a total of 38 teeth. Newborns ("pups") are born with 20 milk teeth which becomes 22 when the final upper premolars emerge. Pups begin losing milk teeth once they have reached a body length of 55–60 mm (2.2–2.4 in); total loss of milk teeth and emergence of adult teeth is usually complete by the time a juvenile is 80 mm (3.1 in) long. [19]
It has a relatively short snout and a gently sloped forehead. It lacks a sagittal crest, which can be used to distinguish it from the Arizona myotis. [2] Its skull length is 14–16 mm (0.55–0.63 in). [20] The braincase appears nearly circular though somewhat flattened when viewed from the back. Its ears are 11.0–15.5 mm (0.43–0.61 in) long, while the tragi, or cartilaginous flaps that project in front of the ear openings, are 7.0–9.0 mm (0.28–0.35 in) long. The tragi are blunt at the tips and considered of medium length for a mouse-eared bat. [2]
The little brown bat is dichromatic and its eyesight is likely sensitive to ultraviolet and red light, based on a genetic analysis that discovered that the genes SWS1 and M/LWS were present and functional. Its ability to see ultraviolet light may be useful in capturing insects, as 80% of nocturnal moths' wings reflect UV light. It is unclear if or how seeing red light is advantageous for this species. [21] It is adapted to see best in low-light conditions. It lacks eyeshine. [2]
The little brown bat lacks a vomeronasal organ. [2] Relative to frugivorous bat species such as the Jamaican fruit bat, it has small eyes and a reduced olfactory epithelium. [22] Instead, it has a more sophisticated system of echolocation, suggesting that reliance on echolocation decreases the need for orientation via sight or smell. [22]
In fall through spring, the little brown bat enters torpor, a state of decreased physiological activity, daily. Torpor saves energy for the bat when ambient temperatures are below 39 °F (4 °C) throughout the year and 32 °F (0 °C) in the winter; instead of expending energy to maintain a constant body temperature, it allows its body to cool and physiological activity to slow. While in torpor, its heart rate drops from up to 210 beats per minute to as few as 8 beats per minute. The exception to this rule is females at the end of pregnancy, which no longer have the ability to thermoregulate, and therefore must roost in warm places. During daily roosting, it can cope with high levels of water loss of up to 25%. [2]
In the winter time, it enters a prolonged state of torpor known as hibernation. To conserve energy, it limits how frequently it arouses from torpor, with individuals existing in uninterrupted torpor for up to 90 days. Arousal is the most energetically costly phase of torpor, which is why individuals do so infrequently. Despite the energy-saving mechanism of hibernation, individuals lose a quarter of their pre-hibernation body mass during the winter. [2]
The little brown bat can be confused with the Indiana bat (M. sodalis) in appearance. The two can be differentiated by the little brown bat's lack of a keeled calcar—the cartilaginous spur on its uropatagium (the flight membrane between its hind legs). While it does have a calcar, that of the little brown bat is not nearly as pronounced. Additionally, the little brown bat can be distinguished by the presence of hairs on its toes and feet that extend beyond the length of the digits. [2] The northern long-eared bat (M. septentrionalis), another similar species, can be distinguished by its much longer ears, and tragi that are long and sharply pointed. [17]
The little brown bat has a promiscuous mating structure, meaning that individual bats of both sexes mate with multiple partners. [23] It is a seasonal breeder, with mating taking place in the fall before the annual hibernation. [17] As a seasonal breeder, males do not produce sperm year-round; instead, spermatogenesis occurs May through August each year. [2] Throughout the spring and summer, males and females roost separately. In the fall, however, individuals of both sexes will congregate in the same roost in a behavior known as "swarming". [24] Like several other bat species, males of this species exhibit homosexual behaviors, with male bats mating indiscriminately with torpid, roosting bats, regardless of sex. [25]
Although copulation occurs in the fall, fertilization does not occur until the spring due to sperm storage. [17] Gestation proceeds for 50–60 days following fertilization. The litter size is one individual. [2] At birth, pups weigh approximately 2.2 g (0.078 oz) and have a forearm length less than 17.2 mm (0.68 in). [26] While they have a small absolute mass, they are enormous relative to their mothers, weighing up to 30% of her postpartum body weight at birth. [27] Pups' eyes and ears are closed at first, but open within a few hours of birth. They exhibit rapid growth; at around three weeks old, the young start flying, begin the weaning process, and are of a similar size to adults in forearm length but not weight. The young are totally weaned by 26 days old. [27] Females may become sexually mature in the first year of life. [2] Males become sexually mature in their second year. [7]
It is a very long-lived species relative to its body size. In the wild, individuals have been documented living up to 34 years. [28] The average lifespan, however, is around 6.5 years. Males and females have high annual survival rates (probability of surviving another year), though survival rates vary by sex and region. One colony documented in Ontario had a male survival rate of 81.6% and a female survival rate of 70.8%; a colony in southern Indiana had survival rates of 77.1% and 85.7% for males and females, respectively. [29]
The little brown bat is a colonial species, with hibernating colonies consisting of up to 183,500 individuals, though the average colony size is little more than 9,000. Historically, individuals within these colonies were highly aggregated and densely clustered together, though the disease white-nose syndrome is making solitary hibernation more common. [30]
During the spring and summer, maternity colonies of almost all female individuals form. [2] These colonies usually consist of several hundred bats. [31] Outside of these maternity colonies, adult males and non-reproductive females will roost by themselves or in small aggregations. Maternity colonies begin to break apart in late summer. [2]
The little brown bat is nocturnal, resting during the day and foraging at night. Individuals typically emerge from their roosts at dusk, foraging for 1.5–3 hours before stopping to roost. A second foraging bout usually occurs later in the night, ending at dawn. [32]
Based on documenting one individual flying in a wind tunnel, it flies at approximately 5.5 km/h (3.4 mph); this increased to 8.9 km/h (5.5 mph) when flying over the surface of water. [33] Home range size is variable; in one study of 22 females in Canada, pregnant females had an average home range of 30.1 hectares (74 acres) and lactating females had an average of 17.6 hectares (43 acres). [34]
It produces calls that are high intensity frequency modulated (FM) and that last from less than one millisecond (ms) to about 5 ms and have a sweep rate of 80–40 kHz, with most of their energy at 45 kHz. [35] Individuals emit approximately 20 calls per second when in flight. [2] [35]
It consumes a variety of arthropod species, including insects and spiders. Prey species include beetles, flies, mayflies, true bugs, ants, moths, lacewings, stoneflies, and caddisflies. [36] It also consumes mosquitoes, with one study documenting that, across twelve colonies in Wisconsin, 71.9% of all little brown bat guano (feces) samples contained mosquito DNA. [37]
During late pregnancy, when energetic demands are high, females consume around 5.5 g (0.19 oz) of insects nightly, or 1.3 g (0.046 oz) of insects per hour of foraging. With an average body mass of 9.0 g (0.32 oz), that means that pregnant females consume 61% of their body weight nightly. Energetic demands during lactation are even higher, though, with females consuming 6.7 g (0.24 oz) of insects nightly, or 1.7 g (0.060 oz) of insects per hour of foraging. Because lactating females have an average mass of 7.9 g (0.28 oz), this means that they consume nearly 85% of their body weight nightly. As the pup grows, lactation requires more and more energy; at the predicted lactation peak of 18 days old, a female would have to consume 9.9 g (0.35 oz) of insects per night, or 125% of her own weight. [27]
An often-mentioned statement is that "bats can eat 1000 mosquitoes per hour." [37] [38] [39] While the little brown bat does consume mosquitoes and has high energetic needs, the study that is the basis for this claim was an experiment in which individuals were put into rooms full of either mosquitoes or fruit flies. [37] [38] For a duration up to 31 minutes, they captured an average of 1.5–5.7 mosquitoes per minute. The individual most efficient at catching fruit flies caught an average of 14.8 per minute for 15 minutes. [40] Extrapolating these numbers results in conclusions that it can eat approximately 340 mosquitoes per hour, or 890 fruit flies. However, there is no assurance that individuals forage with such high efficiencies for long periods of time, or that prey is dense enough in natural settings to allow capture rates observed in enclosed areas. [38]
The little brown bat likely has few predators. Known predators include owls such as the eastern screech owl, northern saw-whet owl, and the great horned owl. [41] Raccoons are also opportunistic predators of the little brown bat, picking individuals off the cave walls of their hibernacula (caves used for hibernation) or eating individuals that have fallen to the cave floor. [42]
The presence of helminth parasites in the gastrointestinal tract of the little brown bat is most common in the spring and fall and least common in the summer. Digenetic trematodes are the most common of these parasites, with the more common of these species including Ototrema schildti and Plagiorchis vespertilionis . [43] The little brown bat is also affected by ectoparasites (external parasites), including bat fleas such as Myodopsylla insignis , chiggers like Leptotrombidium myotis , and the bat mites Spinturnix americanus . [44] When parasitizing a female bat, bat mites synchronize their reproductive cycle with that of their host, with their own reproduction tied to the host's pregnancy hormones. Lactating females have a higher intensity of parasitization by mites, which may promote vertical transmission—the transfer of mites to the bat's offspring. [45]
The little brown bat is affected by the rabies virus—specifically, the strain associated with this species is known as MlV1. However, it is susceptible to other strains of the virus, including those of the big brown bat and the silver-haired bat, which is most lethal to humans. The rabies virus can be present in an individual's saliva, meaning that it can be spread through bites, 12–18 days before the individual begins showing symptoms. Individuals do not always develop rabies after exposure, though. In one study, no little brown bats developed rabies after subcutaneous exposure to the MlV1 strain. [46] Some individuals in the wild have antibodies for the rabies virus. [47]
The little brown bat is also susceptible to the disease white-nose syndrome, which is caused by the fungus Pseudogymnoascus destructans . [48] The disease affects individuals when they are hibernating, which is when their body temperatures are within the ideal growth range of P. destructans, 1–15 °C (34–59 °F). [49] Pseudogymnoascus destructans is the first known pathogen that kills a mammal host during its torpor. [50] Mortality from white-nose syndrome begins to manifest 120 days after hibernation begins, and mortality peaks 180 days after bats enter hibernacula. [51] The growth of P. destructans on bats erodes the skin of their wing and tail membranes, muzzles, and ears. White-nose syndrome causes affected bats to burn through their energy reserves twice as fast as uninfected individuals. In addition to visible fungus growth on the nose, ears, and wings, white-nose syndrome results in higher carbon dioxide levels in the blood, causing acidosis, and hyperkalemia (elevated blood potassium). Arousal from torpor becomes more frequent, and water loss increases due increased respiration rate in an attempt to remove excess carbon dioxide from the blood. [52] The premature loss of fat reserves during hibernation results in starvation. [50]
Survivors of white-nose syndrome have longer bouts of torpor and lower body temperatures during torpor than individuals that die. [50] Some individuals are more likely to survive based on their genetics, which predisposes them to remain in torpor longer and have larger fat reserves. [53] Little brown bats are most affected by white-nose syndrome when they exhibit social, grouping behavior when hibernating, as P. destructans is transmitted by direct contact. In hibernacula where bats exhibit more solitary behavior, colonies are more prone to avoid infections of white-nose syndrome. In some colonies where grouping behavior was common before exposure to white-nose syndrome, bats now hibernate in a more solitary fashion. Before white-nose syndrome, only 1.16% of little brown bats hibernated singly; after white-nose syndrome, the percentage grew to 44.5%. [30]
The little brown bat lives throughout much of North America. [2] In the north, its range extends as far west as Alaska and across much of Canada to Labrador. In the south, its range extends to Southern California and across the northern parts of Arizona and New Mexico. [1] Historically, the largest known aggregations of this species occurred in the karstic regions of the Eastern United States. [48]
The little brown bat roosts in sheltered places during the day. These roosts can include human structures or natural structures such as tree hollows, wood piles, rocky outcrops, or, occasionally, caves. [54] [2] Species of trees used for roosting include quaking aspen, balsam poplar, oak, and maple. [55] [56] [17] It prefers roosts that are warm and dark. [2] For maternity colonies, females prefer roosts that are 23.3–34.4 °C (73.9–93.9 °F). [17]
The little brown bat hibernates in caves or old mines. Females migrate up to hundreds of kilometers from their summer ranges to reach these hibernacula. It prefers hibernacula in which the relative humidity is greater than 90% and ambient temperatures are above the freezing point. [2] Preferred hibernacula also maintain a constant temperature throughout the winter. [17]
The little brown bat forages along the edges of vegetated habitat. [55] It also forages along the edges of bodies of water or streams. [2] In one study in the Canadian province of Alberta, its foraging activity was significantly higher in old-growth forest than would be expected based on its relative availability. [55]
As of 2021, the little brown bat is evaluated as an endangered species by the IUCN, a dramatic change from 2008 when it was designated as the lowest conservation priority, least concern. [1] Until recently, the species was regarded as one of the most common bats in North America. [57] However, a serious threat to the species has emerged in the form of a fungus-caused disease known as white-nose syndrome. [58] It was one of the first bat species documented with the disease, which now affects at least seven hibernating bat species in the United States and Canada. [48] From 2006 to 2011, over one million little brown bats died from the disease in the Northeastern United States, with winter hibernacula populations declining up to 99%. [58] As of 2017, hibernacula counts for little brown bats in the Northeast had declined by an average of 90%. [59]
White-nose syndrome first appeared in New York in 2006; it has steadily diffused from eastern New York, though, until recently, remaining east of the Rocky Mountains. In March 2016, white-nose syndrome was detected on a little brown bat in King County, Washington, representing a 1,300 mi (2,100 km) jump from the previous westernmost extent of the disease in any bat species. [60]
In 2010, Frick et al. predicted a 99% chance of local extinction of little brown bats by the year 2026. They also predicted that the pre-white-nose syndrome population of 6.5 million individuals could be reduced to as few as 65,000 (1%) via the disease outbreak. [61] Despite heavy declines, the species has avoided extinction in the Northeast through the persistence of small, localized populations. While the mortality rate of the disease is very high, some individuals that are exposed do survive. [59]
In 2010, Kunz and Reichard published a report arguing that the precipitous decline of the little brown bat justified its emergency listing as a federally endangered species under the U.S. Endangered Species Act. [62] However, it is not federally listed as threatened or endangered as of 2018, though several U.S. states list it as endangered (Connecticut, [63] Maine, [64] Massachusetts, [65] New Hampshire, [66] Pennsylvania, [67] Vermont, [68] Virginia [69] ), threatened (Tennessee, [70] Wisconsin [17] ), or of Special Concern (Michigan, [71] Ohio [72] ).
The little brown bat was listed as an endangered species by the Committee on the Status of Endangered Wildlife in Canada in February 2012 after an emergency assessment. The emergency designation as endangered was confirmed in November 2013. [73]
Little brown bats commonly occupy human structures. Females will situate maternity colonies within buildings. [74] This small body size of this species can make it challenging to prevent individuals from entering a structure, as they can take advantage of gaps or holes as small as 3.8 cm (1.5 in) × 0.64 cm (0.25 in). Once inside a building, a colony of little brown bats can disturb human inhabitants with their vocalizations and production of guano and urine. Large accumulations of guano can provide a growth medium for fungi, including the species that causes histoplasmosis. Concerns about humans becoming affected by bat ectoparasites such as ticks, fleas, or bat bugs are generally unfounded, as parasites that feed on bats are often specific to bats and die without them. [75]
Because they are often found in proximity to humans, the little brown bat and the not-closely related big brown bat are the two bat species most frequently submitted for rabies testing in the United States. [46] Little brown bats infrequently test positive for the rabies virus; of the 586 individuals submitted for testing across the United States in 2015, the most recent data available as of 2018, 16 (2.7%) tested positive for the virus. [76]
Little brown bats are a species that will use bat houses for their roosts. [77] Landowners will purchase or construct bat houses and install them, hoping to attract bats for various reasons. Some install bat houses in an attempt to negate the effects of removing a colony from a human structure ("rehoming" them into a more acceptable space). While this can be effective for other species, there is not evidence to suggest that this is effective for little brown bats, [74] though it has been shown that little brown bats will choose to occupy artificial bat boxes installed at the sites of destroyed buildings that once housed colonies. [78] Others are attempting to help bats out of concern for them due to the effects of white-nose syndrome. [79] Bat houses are also installed in an attempt to control the bats' insect prey such as mosquitoes or taxa that harm crops. [80]
Little brown bats are vulnerable near moving vehicles on roads, either foraging or crossing. Bats can easily be pulled into the slipstreams of faster moving vehicles. When little brown bats cross roads, they approach the road using canopy tree cover and avoid crossing where there is no cover. When the cover is lower, bats cross roads lower. [81]
Horseshoe bats are bats in the family Rhinolophidae. In addition to the single living genus, Rhinolophus, which has about 106 species, the extinct genus Palaeonycteris has been recognized. Horseshoe bats are closely related to the Old World leaf-nosed bats, family Hipposideridae, which have sometimes been included in Rhinolophidae. The horseshoe bats are divided into six subgenera and many species groups. The most recent common ancestor of all horseshoe bats lived 34–40 million years ago, though it is unclear where the geographic roots of the family are, and attempts to determine its biogeography have been indecisive. Their taxonomy is complex, as genetic evidence shows the likely existence of many cryptic species, as well as species recognized as distinct that may have little genetic divergence from previously recognized taxa. They are found in the Old World, mostly in tropical or subtropical areas, including Africa, Asia, Europe, and Oceania.
The tricolored bat or American perimyotis 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.
The gray bat is a species of microbat endemic to North America. It once flourished in caves all over the southeastern United States, but due to human disturbance, gray bat populations declined severely during the early and mid portion of the 20th century. 95% of gray bats now hibernate in only 15 caves. M. grisescens has been listed as federally endangered by the U.S. Fish and Wildlife Service since 1976, and is protected under the Endangered Species Act. Gray bat populations were estimated at approximately 2 million bats around the time they were placed on the Endangered Species list. By the early 1980s populations of gray bats dropped to 1.6 million. With conservation efforts in place, in 2004, gray bat populations were estimated to have reached 3.4 million.
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 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 evening bat is a species of bat in the vesper bat family that is native to North America. Hunting at night, they eat beetles, moths, and other flying insects.
The common noctule is a species of insectivorous bat common throughout Europe, Asia, and North Africa.
The greater mouse-eared bat is a European species of bat in the family Vespertilionidae.
A panzootic is an epizootic that spreads across a large region, or even worldwide. The equivalent in human populations is called a pandemic.
Rafinesque's big-eared bat, sometimes known as the southeastern big-eared bat, is a species of vesper bat native to the southeastern United States.
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 long-legged myotis is a species of vesper bat that can be found in western Canada, Mexico, and the western United States.
The Yuma myotis is a species of vesper bat native to western North America.
White-nose syndrome (WNS) is a fungal disease in North American bats which has resulted in the dramatic decrease of the bat population in the United States and Canada, reportedly killing millions as of 2018. The condition is named for a distinctive fungal growth around the muzzles and on the wings of hibernating bats. It was first identified from a February 2006 photo taken in a cave located in Schoharie County, New York. The syndrome has rapidly spread since then. In early 2018, it was identified in 33 U.S. states and seven Canadian provinces; plus the fungus, albeit sans syndrome, had been found in three additional states. Most cases are in the eastern half of both countries, but in March 2016, it was confirmed in a little brown bat in Washington state. In 2019, evidence of the fungus was detected in California for the first time, although no affected bats were found.
The Virginia big-eared bat is one of two endangered subspecies of the Townsend's big-eared bat. It is found in Virginia, West Virginia, North Carolina, and Kentucky. In 1979, the US Fish and Wildlife Service categorized this as an endangered species. There are about 20,000 left and most of them can be found in West Virginia. The Virginia big-eared bat is the state bat of Virginia.
Pseudogymnoascus destructans is a psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), a fatal disease that has devastated bat populations in parts of the United States and Canada. Unlike species of Geomyces, P. destructans forms asymmetrically curved conidia. Pseudogymnoascus destructans grows very slowly on artificial media and cannot grow at temperatures above 20 °C. It can grow around 4 °C to 20 °C, which encompasses the temperatures found in winter bat hibernacula. Phylogenic evaluation has revealed this organism should be reclassified under the family Pseudeurotiaceae, changing its name to Pseudogymnoascus destructans.
Myotis septentrionalis, known as the northern long-eared bat or northern myotis, is a species of bat native to North America. There are no recognized subspecies. The northern long-eared bat is about 3–3.7 inches in length, with a wingspan of 9–10 inches. It is distinguishable by its long ears when comparing it to other bats in its genus. This species is commonly found in the northern United States and Southern Canada east of British Columbia. The geographic range includes 37 states.
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.
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.