Perception Channels: tactile ; chemical
Roost disturbance is the greatest threat to Idionycteris phyllotis. Mining activities have caused the relocation or extermination of several bat roosts. Reproduction is shown to decrease after relocation, threatening the survival of the roost. Deforestation removes the feeding environment for the bats, as well as that of their insect prey.
Temperate North American bats are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. While there are currently no reports of Idionycteris phyllotis mortalities as a result of white-nose syndrome, the disease continues to expand its range in North America.
US Federal List: threatened
CITES: no special status
IUCN Red List of Threatened Species: least concern
Bats are known to carry the causative virus of rabies
Because Idionycteris phyllotis is an insectivorous bat it plays an important role in pest control. Bat guano is used as a source of fertilizer, and organisms housed in the guano are used for waste detoxifying.
Idionycteris phyllotis is an insectivorous bat which feeds mostly by gleaning moths and stationary insects from surfaces.
Idionycteris phyllotis is found in the mountainous regions of the southwestern United States through central Mexico.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Idionycteris phyllotis primarily dwells in caves in mountainous pine and oak forests. The availability of water holes is a significant factor in habitat selection due to their high rate of evaporative water loss. Nearly all capture sites have been in the vicinity of rocks, such as cliffs or large boulders, their most probable roosting sites.
Terrestrial Biomes: forest ; scrub forest ; mountains
The defining characters of Idionycteris phyllotis, also known as Allen's Big-Eared Bat, are its large ears (34 to 43 mm) which possess lappets projecting from the base of the ears and extending over the forehead. Idionycteris phyllotis has a total length of 103 to 118mm, a tail length of 44 to 55mm, and a forearm length of 42 to 49 mm. The wing span of I. phyllotis ranges from 302 to 344mm. Dorsal and ventral pelage is long (10mm) and basally black with yellowish gray tips. A patch of white hair occurs at the base of the ears. Females are generally about 5% larger in head and body length, however, there is no difference in forearm length.
Range mass: 8 to 16 g.
Other Physical Features: endothermic ; bilateral symmetry
Females form maternity colonies during the summer months, from June to late July, where they give birth to and raise their young. Maternity colonies consist of an average of 30 females. Males live separately from the females during this time. Females give birth to a single young.
Range number of offspring: 1 to 1.
Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Allen's big-eared bat (Idionycteris phyllotis) is a species of vesper bat in the monotypic genus Idionycteris. It occurs in Mexico and in Arizona, California, Nevada, New Mexico, Utah, and Colorado[2] in the United States.[1]
Idionycteris is a bat with large ears, weighing 8 to 16 grams. On the dorsal side they possess long and soft pelage,[3] also referred to as fur. Their fur is basally blackish in color with tips that are a yellow-gray color. Idionycteris, has a black patch on each shoulder, a tuft of white hair on the backside of the ears, as well as, ventral hairs that are black with pale tips.[3] The calcar possesses a low keel. The uropatagium has 12 to 13 transverse ribs. The rostrum is flattened and broad.[3]
Idionycteris phyllotis has an external morphology like that of gleaning bats, which means they have adaptions required for plucking stationary insects from surfaces.[3] To do this, they have long tragi and ears, wings adapted for maneuverability and hovering flight, and a gracile jaw.[3] Allen’s big-eared bat (Idionycteris phyllotis) is the only species in North America known to emit long, constant frequency-frequency modulated echolocation calls.[2]
The Allen’s big-eared bat inhabits the southwestern mountainous regions of Mexico and the United States. This species, occupies a wider range in elevation, ranging from 855 m to 3,225 m, while most specimens reside at altitudes between 1,100 m and 2,500 m.[3]
Allen's big-eared bat (Idionycteris phyllotis) is a species of vesper bat in the monotypic genus Idionycteris. It occurs in Mexico and in Arizona, California, Nevada, New Mexico, Utah, and Colorado in the United States.
