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Findley's Myotis

Myotis findleyi
EN · Endangered Chiroptera Vespertilionidae
Size
4-5 cm + forearm 3.5-3.8 cm
Weight
6-9 g
Activity
Nocturnal
Sociability
Colonies of tens of individuals

Description

Findley's Myotis lives solely on a small archipelago off Mexico's Pacific coast, the Tres Marías Islands—a range so tiny that a single adverse event on that island scale could wipe out the entire species. Its name honours a renowned American mammalogist specialising in North American bat fauna, who documented much of the diversity of Mexican bats throughout the 20th century. Like other bats in its genus, it hunts flying insects using echolocation, though its minuscule home range makes it one of the least studied American Myotis of all. Surrounded by sea in every direction, its island population has been isolated from mainland relatives for generations.

How to identify it

A small bat with reddish-brown fur, medium-sized ears and relatively short, broad wings. It can be confused with other Myotis species from the Mexican Pacific coast, whose reliable separation often requires cranial or genetic examination; its exclusive presence on the Tres Marías Islands, with no overlap with mainland populations, is the most reliable guide to identification.

Habitat and range

Dry tropical forest vegetation and coastal areas of the Tres Marías Islands, in island lowlands. Endemic to this small archipelago off the Pacific coast of Nayarit state, Mexico, with no natural presence outside these islands.

Diet

Insectivorous, hunting flying insects on the wing over coastal vegetation and open areas of the Tres Marías Islands.

Behaviour

Forms colonies in caves, rock crevices or tree hollows on its home islands, with social behaviour poorly documented given the scarcity of studies on this island population.

Conservation

Restricted to an area of barely 900 km² spread across fewer than five known locations, its populations are in continuous decline due to island habitat transformation from urbanisation, livestock and introduced species.

Threats

Urbanisation and infrastructure development on the Tres Marías Islands, introduction of livestock and invasive species that alter native vegetation, and extreme geographic restriction to a very small archipelago.

Other accounts in Vespertilionidae

See all species accounts for bats · Full species index

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