The silver-haired bat (''Lasionycteris noctivagans'') is a solitary migratory species of

vesper bat 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 famili ...

in the family Vespertilionidae and the only member of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Lasionycteris''.

Etymology

The species name translates as night-wandering, referring to the

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 ...

behavior of bats.

Description

This medium-sized bat is predominantly black (including the wings, ears, interfemoral membrane, and fur) with white-tipped hairs. The basal upper half of its tail membrane is densely furred. This gives the bat a frosted appearance and its common namesake. This species has a flattened skull with a broad rostrum. This species weighs around 8–12 g, has a total length of ~100 mm, a tail length of 40 mm, and a forearm length of 37–44 mm.

Distribution and habitat

''Lasionycteris noctivagans'' is found in

Bermuda Bermuda is a British Overseas Territories, British Overseas Territory in the Atlantic Ocean, North Atlantic Ocean. The closest land outside the territory is in the American state of North Carolina, about to the west-northwest. Bermuda is an ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, and the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

. This forest inhabitant is known to occur from southeastern

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

in summer to northeastern

in winter and is found in arid habitats at low elevations during seasonal migrations. In Missouri, reproduction occurs in the northern dissected plains region, but reproductive females are believed to be absent from the southern Ozark highlands in the summer. They often roost in tree cavities or in bark crevices on tree trunks, especially during migration. Their unique coloration makes them blend in with their roosting environment.Coming in Contact with Bats
Centers for Disease Control and Prevention National Center for Emerging and Zoonotic Infectious Diseases (NCEZID) Division of High-Consequence Pathogens and Pathology (DHCPP). However, some individuals seem to overwinter in buildings, which may allow them to spend the winter in places that would otherwise be too cold for them.

Life history

Copulation of tree bats is likely initiated during flight. After mating, tree bats hibernate alone in tree cavities, bark crevices, beneath leaf litter, or in the twilight zone of caves. Gestation typically takes 50–60 days, so that parturition of pups occurs in early summer when insect availability is high. Pups are born breech by presentation, and the mother consumes the placenta Females typically give birth to two offspring, with an even sex ratio.

Diet and foraging behavior

Silver-haired bats consume primarily soft-bodied insects, such as moths, but will also take spiders and harvestmen. This species will forage low, over both still and running water, and also in forest openings. Silver-haired bats are slow but maneuverable flyers that typically detect prey a short distance away.

Conservation threats

In addition to the

hoary bat The hoary bat (''Lasiurus cinereus'') is a species of bat in the vesper bat family, Vespertilionidae. It lives throughout most of North America (and possibly also in Hawaii, although this is disputed). Taxonomy The hoary bat was described as ...

(''Lasiurus cinereus'') and eastern red bat (''Lasiurus borealis''), the silver-haired bat is one of the three tree bat species most commonly killed at wind energy facilities (over 75% of the mortalities). The causative agent of white-nose syndrome, ''

Pseudogymnoascus destructans ''Pseudogymnoascus destructans'' (formerly known as ''Geomyces destructans'') is a Psychrophile, psychrophilic (cold-loving) fungus that causes white-nose syndrome (WNS), a fatal disease that has devastated bat populations in parts of the United ...

'', has been detected on a silver-haired bat in Delaware, although this species does not suffer the same mass mortalities observed in smaller-bodied hibernating North American cave bats. Like all bats, silver-haired bats are vulnerable to population threats because of their inherently low reproductive rate.

Rabies

Most bats do not have rabies; however, most recent human rabies deaths have been due to a strain of rabies associated with this species. In 2015, a Wyoming woman woke up to a bat on her shoulder later to be identified as a silver-haired bat. She presented to the emergency department several weeks later with ataxia, dysphagia, and weakness. After over a week of diagnostic workup, she was determined to have the rabies virus, which was traced to the bat incident. She died several days later.

References

{{Taxonbar, from=Q28972 Mammals described in 1831 Taxa named by John Eatton Le Conte Bats of Canada Bats of the United States Fauna of Bermuda Bats of Mexico Vesper bats Taxonomy articles created by Polbot