Endangered
Little brown bat
Myotis lucifugus
Little brown bat is a bat in the family Vespertilionidae (order Chiroptera) — Myotis lucifugus, recorded as Endangered.
Appearance
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). 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.
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).
Range and habitat
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. Historically, the largest known aggregations of this species occurred in the karstic regions of the Eastern United States.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Historically, individuals within these colonies were highly aggregated and densely clustered together, though the disease white-nose syndrome is making solitary hibernation more common. 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. The little brown bat has a promiscuous mating structure, meaning that individual bats of both sexes mate with multiple partners.
In crisis
It has few natural predators, but may be killed by raptors such as owls, as well as terrestrial predators such as raccoons. In the Northeastern United States, population loss has been extreme, with surveyed hibernacula (caves used for hibernation) averaging a population loss of 90%. 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.
Even so, a serious threat to the species has emerged in the form of a fungus-caused disease known as white-nose syndrome. 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%.
Little brown bat is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Little brown bat, Wikidata item Q746127. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
