Mexican big-eared bat
|Mexican big-eared bat|
G.M. Allen, 1916
The Mexican big-eared bat (Corynorhinus mexicanus) is a species of vesper bat. They are nocturnal and insectivorous. Their very large ears are located across their foreheads, and when captured, the bats are observed to curl their ears in a protective manner. The adults are usually brown colored, while the juveniles are usually a smokey brown color. They have small noses.
Habitat and distribution
The Mexican big-eared bat has been identified in Mexico (where they are a native species), Arizona and even as far north as Utah. They are found in high, humid, mountain habitats and seem to prefer areas with pine-oak forests, although they have been found around other types of vegetation, such as sycamore, cottonwood and agave. Being a nocturnal species, they rest during the day, their day-time roosts in open caves and mine shafts.
Studies of the males of the species show they have one long reproductive cycle per year. The timing of their cycle is dependent on both physiological (body condition, neurological, and endocrine signals) and environmental (temperature and resource availability) factors. The male reproductive organs are the smallest in February, March, and April, then begin development in May and reach their biggest size, determined by weight, around August (where they are about 40 times bigger than they were in April). The best body conditions of the bats were found from May to June, which suggests this cycle is dependent on body condition.
In 1996, the species was listed as lower risk/least concern, but in 2008, it was moved to near threatened. The population sizes of this bat are declining, and the species may soon be threatened. The major threat to the species is humans, disturbing their roosts and causing habit loss.
- Arroyo-Cabrales, J. & Reid, F. 2008. Plecotus mexicanus. 2008 IUCN Red List of Threatened Species.
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- Allen, G.M. (1916). "Bats of Genus of Corynorhinus". Bulletin of the Museum of comparative zoology 60: 331–356.
- Black, H.L. 1970 (1970). "Occurrence of the Mexican Big-Eared Bat in Utah". Journal of Mammalogy 51: 190. doi:10.2307/1378562.
- Handley, C.O. (1955). "A new pleistocene bat (Corynorhinus) from Mexico". Journal of the Washington Academy of Science 45: 48–49.
- Anderson, S. (1972). "Mammals of Chihuahua, taxonomy and distribution". Bulletin of the American Museum of Natural History 148: 149–410. hdl:2246/1101.
- Miguel, A.L.G.; López-Wilchis, Ricardo; Hernández-Pérez, Omar; Arenas-Ríos, Edith; Rosado, Adolfo (2005). "Male Reproductive Cycle of Mexican Big-Eared Bats, Corynorhinus mexicanus (Chiroptera Vespertilionidae)". In Edwards, Cody. The Southwestern Naturalist 50 (4): 453–460. doi:10.1894/0038-4909(2005)050[0453:MRCOMB]2.0.CO;2.
- Ceballos, G. and Oliva, G. 2005. Los mamíferos silvestres de México. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad and Fondo de Cultura Económica, México.
- Arroyo-Cabrales, J. & Reid, F. 2008. Plecotus mexicanus. 2008 IUCN Red List of Threatened Species. Downloaded on 04/24/2012