Allen's big-eared bat (''Idionycteris phyllotis''), also known as the lappet-browed bat, is a species of

vesper bat Vespertilionidae is a family of microbats, of the order Chiroptera, flying, insect-eating mammals variously described as the common, vesper, or simple nosed bats. The vespertilionid family is the most diverse and widely distributed of bat famili ...

in the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

genus ''Idionycteris''. It occurs in

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

and in

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, and

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

Description

''Idionycteris phyllotis'' is a bat with large ears, weighing 8 to 16 grams. On the

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

side they possess long and soft

pelage A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...

, (fur). Their fur is basally blackish in color with tips that are a yellow-gray color. They have a black patch on each shoulder, a tuft of white hair on the backside of the ears, as well as

ventral Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

hairs that are black with pale tips. The

calcar The calcar, also known as the calcaneum, is the name given to a spur of cartilage arising from inner side of ankle and running along part of outer interfemoral membrane in bats, as well as to a similar spur on the legs of some arthropods. The cal ...

possesses a low keel. The

uropatagium The patagium (: patagia) is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, theropod dinosaurs (including b ...

has 12 to 13 transverse ribs. The

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit ** podium * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ...

is flattened and broad. They have distinctive lappets (disc-shaped protrusions), which project from the base of the ears onto the brow of the bat. ''I. phyllotis'' has an external

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

common to that of gleaning bats, and are thus well adapted for plucking stationary insects from surfaces. To do this they have long tragi and ears, wings adapted for maneuverability and hovering flight, and a

gracile Gracility is slenderness, the condition of being gracile, which means slender. It derives from the Latin adjective ''gracilis'' (masculine or feminine), or ''gracile'' ( neuter), which in either form means slender, and when transferred for examp ...

jaw. ''I. phyllotis'') is the only species in North America known to emit long, constant frequency-frequency modulated echolocation calls.

Range and habitat

Allen's big-eared bat inhabits the southwestern mountainous regions of Mexico and the United States. This species occupies a wide range in elevation, ranging from 855 m to 3,225 m, though most specimens reside at altitudes between 1,100 m and 2,500 m.

References

{{Taxonbar, from=Q247338 Vesper bats Bats of Mexico Bats of the United States Bat, Allen Bat, Allen Bat, Allen Bat, Allen Bat, Allen Bat, Allen Mammals described in 1916 Taxa named by Glover Morrill Allen Taxonomy articles created by Polbot