California Leaf-nosed Bat

Taxobox
name = California Leaf-nosed Bat


status = VU | status_system = IUCN2.3
regnum = Animalia
phylum = Chordata
classis = Mammalia
ordo = Chiroptera
familia = Phyllostomidae
genus = "Macrotus"
species = "M. californicus"
binomial = "Macrotus californicus"
binomial_authority = Baird, 1858
synonyms = The California Leaf-nosed Bat ("Macrotus californicus") is a species of bat in the Phyllostomidae family. It is found in Mexico and the United States. Its natural habitat is hot deserts. It is threatened by habitat loss.

Habitat

California leaf-nosed bats can be found in Sonoran and Mojave Desert scrub habitats in the Colorado River valley in southern California, Nevada and Arizona, and throughout western Mexico. It is non-migratory and does not hibernate.

Biology

The California leaf-nosed bat weighs between 12 and 20 grams, has a wingspan of over 30 centimeters and a body length of over 6 centimeters, and is brown in color. As its name implies, it has a triangular fleshy growth of skin, called a noseleaf, protruding above the nose. This bat is the only bat of the Phyllostomidae family in the United States to have large ears, usually over 2.5 centimeters. It is also one of the most maneuverable in flight. With short, broad wings, it can fly at low speeds using minimal energy. Because of this adaptation, it is not suited for long-distance travel, and is non-migratory.cite book | last = Steven J. Phillips, Patricia Wentworth Comus (eds.) | title = A Natural History of the Sonoran Desert | publisher = University of California Press | date = 2000 | pages = 464-466 | isbn = 0-520-21980-5 ]

This bat has an unusual reproductive pattern. After breeding occurs in the fall, the embryos develop very slowly until March, when growth continues at a more normal rate before birth in May or June. Twins are common.

This bat is a "gleaning" insectivore which captures prey such as crickets, grasshoppers, beetles, and sphinx moths straight from the ground or foliage rather than in flight. It prefers to use its large eyes to detect prey, although in total darkness it will switch to echolocation. It typically hunts within a few feet of the ground using its superior eyesight to search for insects. It does not alight to capture its prey, but hovers above it and snags it off the substrate. It then carries its prey to an open roost such as a porch or open building to dismember, then consume it.

Human Impact

They are susceptible to human disturbance which can be especially detrimental to the species during summer months when these bats are rearing young. Human disturbance of caves in which they roost is a major threat. Furthermore, because they often roost in abandoned mines, reclamation practices and re-working old mines can severely impact populations. Because California leaf-nosed bats do not hibernate or migrate, the relatively warm mine shafts are critical for its survival in the northern portions of its range.

References

* Chiroptera Specialist Group 1996. [http://www.iucnredlist.org/search/details.php/12652/all Macrotus californicus] . [http://www.iucnredlist.org 2006 IUCN Red List of Threatened Species. ] Downloaded on 30 July 2007.
* Species Profile at Bat Conservation International. [http://www.batcon.org/SPprofiles/detail.asp?articleID=75] .