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Lasionycteris noctivagans

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA MAMMALIA CHIROPTERA VESPERTILIONIDAE

Scientific Name: Lasionycteris noctivagans
Species Authority: (La Conte, 1831)
Common Name(s):
English Silver-haired Bat

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Arroyo-Cabrales, J., Miller, B., Reid, F., Cuarón, A.D. & de Grammont, P.C.
Reviewer(s): Medellín, R. (Chiroptera Red List Authority) & Schipper, J. (Global Mammal Assessment Team)
Justification:
This species is listed as Least Concern in because of its wide distribution, presumed large population, occurrence in protected areas, tolerance to some degree of habitat modification, and because it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category.
History:
1996 Lower Risk/least concern (Baillie and Groombridge 1996)

Geographic Range [top]

Range Description: S Canada, USA (including SE Alaska, and except extreme southern parts), NE Mexico, Bermuda (Simmons 2005)
Countries:
Native:
Bermuda; Canada; Mexico; United States
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Silver-haired bats have been reported to be one of the earliest fliers in the evening, sometimes appearing in broad daylight. However, other sources claim that these bats are late-evening fliers. The flying time of silver-haired bats is believed to be adjusted by the bat so that it will not conflict with the flying times of the red, hoary, or big brown bats. Silver haired-bats are believed to be one of the slowest flying bats in North America (possibly second to western pipistrelles), with a flight speed of 4.8-5.0 m/s (Naumann 1999).
The adults usually appear singly, but can occasionally be found in pairs or small groups. During the summer, the bats are believed to segregate by sex. During late summer and autumn, however, silver-haired bats join in groups containing both sexes to migrate to the southern parts of their range. Some silver-haired bats are also known to hibernate in the northern locations (Naumann 1999).
It is rare in Mexico (Arroyo-Cabrales pers. comm.).
Population Trend: Stable

Habitat and Ecology [top]

Habitat and Ecology: Silver-haired bats prefer temperate, northern hardwoods with ponds or streams nearby. The typical day roost for the bat is behind loose tree bark. Silver-haired bats appear to be particularly fond of willow, maple and ash trees (most likely due to the deeply fissured bark). Hollow snags and bird nests also provide daytime roosting areas for silver-haired bats. Less common daytime roosts include buildings, such as open sheds and garages; however, due to their solitary nature and adaptation to woodland roosts, these bats rarely invade buildings in large enough numbers to cause alarm. During the winter months, silver-haired bats that hibernate find shelter in northern areas inside trees, buildings, rock crevices, and similar protected structures (Naumann 1999).
ourtship and mating of silver-haired bats occurs in autumn when both sexes congregate for migration. Fertilization is delayed until the next spring. Births occur after a gestation period of 50 to 60 days. At parturition, the female roosts with her head facing upward. The tail membrane is bent forward to form a basket, in which the young are caught as they leave the birth canal. Two young are produced, usually between late June and early July (Naumann 1999).
Silver-haired bats are insectivorous. Their diet mainly consists of flies, beetles, and moths. However, these bats feed opportunistically on any concentration of insects they come across. They have a short-range foraging strategy, traveling over woodland ponds and streams. Silver-haired bats do not always feed in mid-flight; they have been caught in mouse traps, suggesting ground foraging, and they have been reported to consume larvae on trees (Naumann 1999).
Systems: Terrestrial

Threats [top]

Major Threat(s): Silver-haired bats have no special endangered or threatened status; however, activities such as logging and deforestation may pose a threat for the bat in the future (Naumann 1999).

Conservation Actions [top]

Conservation Actions: In Mexico is listed as subject to special protection under NOM - 059 - SEMARNAT - 2001 (Arroyo-Cabrales pers. comm.).
Found in protected areas.

Citation: Arroyo-Cabrales, J., Miller, B., Reid, F., Cuarón, A.D. & de Grammont, P.C. 2008. Lasionycteris noctivagans. The IUCN Red List of Threatened Species. Version 2014.1. <www.iucnredlist.org>. Downloaded on 22 July 2014.
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