Choeronycteris mexicanaMexican long-tongued bat

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Geographic Range

Choeronycteris mexicana is common throughout Mexico with its range extending through Central America and into northern South America. It is also found in some areas of the southwestern United States. The Mexican Long-tongued bat has been found in southern Texas, New Mexico, Arizona, and California. The bat enters these states from Mexico at their very southern border. The Mexican long-tongued bat is rare in the United States. The scarcity of Choeronycteris mexicana in the United States is influenced by temperature and seasonal food availabitity. Some members of the species that inhabit the United States migrate to the southern parts of its range for the winter season.

Habitat

Choeronycteris mexicana lives in a variety of habitats ranging from desert, montane, riparian, to pinyon-juniper habitats. The bats are most frequently found roosting in desert canyons, deep caves, mines, or rock crevices. In urban enviroments the bats use abandoned buildings for day roosts. Choeronycteris mexicana inhabits altitudes up to 6,200 feet.

  • Range elevation
    1000 (high) m
    3280.84 (high) ft

Physical Description

The Mexican Long-tongued bat is a medium sized bat with a long rostrum and a nose leaf. It has a long tongue that extends to 1/3 of its body length. It' pelage is gray to brown above and lighter below. Other characteristics include big eyes and a minute tail that extends less than halfway to the edge of the interfemoral membrane.

Average external measurements:

total length-85mm, tail-10mm, foot-14mm, ear-16mm,

forearm-44mm, weight-25g

dental formula

2/0 1/1 2/3 3/3 (X2)=30

  • Average mass
    25 g
    0.88 oz
  • Average length
    85 mm
    3.35 in

Reproduction

Breeding occurs during the summer months in the northernmost part of the range of Choeronycteris mexicana. Each female bears a single furred young between late June and early July. In southern Mexico young have been seen as early as mid-april. Caves, mines, rock crevices, and abandoned buildings are used as nursery sites. The young remain with their mother until they can fly, 2-3 weeks after birth. Females are known to carry their young in flight. Once young can fly, Choeronycteris mexicana may move their roosts to areas of greater food availability. Young born in the southern United States leave their maternity roosts in October and November for Mexico, Central America, or the northern parts of South America.

  • Breeding season
    June-July
  • Range number of offspring
    1 (low)
  • Average number of offspring
    1
  • Average weaning age
    2-3 weeks

Behavior

Peak activity occurs 1 1/2 hours after sunset and then at low levels until about 3 hours after sunset. Bats hang by one foot while roosting and can rotate 360 degrees. The bats may be found singly or in groups of several dozen. At temperatures below 70 degrees F, they hang in a cluster and above 70 degrees F they hang one to two inches apart. Choeronycteris mexicana migrates south in the winter to follow flowering food plants such as agave and yucca.

Communication and Perception

Food Habits

Choeronycteris mexicana feeds on fruit, pollen, nectar, and possibly insects on rare occasions. They have a long tongue that aids in removing nectar from flowers. Pollen and nectar is acquired mainly from night blooming flowers such as cactus and agave. Nectar and pollen is typically collected while the bat hovers over the flower. Hummingbird feeders provide food for those bats arriving to northern destinations when food sources are not yet available.

  • Animal Foods
  • insects
  • Plant Foods
  • fruit
  • nectar
  • pollen

Ecosystem Roles

Pollinates agave and columnar cacti.

May share roosts with Plecotus townsendii and Macrotus californicus.

  • Ecosystem Impact
  • pollinates

Economic Importance for Humans: Positive

Choeronycteris mexicana pollinates Agave plants.

Conservation Status

The Mexican Long-tongued bat is the only nectar feeding bat that is not endangered. It is listed by the United States Fish and Wildlife service as a species of concern. Fewer than 400 bats have been seen in the United States since 1906. A long term sustainable food source is important for the survival of the species. Development, prescribed fires, and grazing threaten loss of food plants. Other threats to Choeronycteris mexicana are caving, natural or intentional mine closures, and mine reclamation.

Contributors

Shelly Charron (author), University of Michigan-Ann Arbor, Bret Weinstein (editor), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fertilization

union of egg and spermatozoan

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

internal fertilization

fertilization takes place within the female's body

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nectarivore

an animal that mainly eats nectar from flowers

nocturnal

active during the night

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

References

"Biological Status of Choeronycteris Mexicana (Mexican long-tongued bat) in the United States and Mexican Borderlands: a Species at Risk Project" (On-line). Accessed (Date Unknown) at http://www.mesc.nbs.gov/projects/bio_choero.html.

"Biota Information System of New Mexico" (On-line). Accessed October 9, 2001 at http://www.fw.vt.edu/fishex/nmex_main/species/050070.htm.

1994. "Mexican Long-tongued Bat" (On-line). Accessed October 8, 2001 at http://www.nsrl.ttu.edu/tmot1/choemexi.htm.

Harris, J. 1999. "Mexican Long-tongued Bat" (On-line). Accessed October 8, 2001 at http://www.sibr.com/mammals/M020.html.

Hershkovitz, P. March 1969. The Recent Land Mammals of the Neotropical Region: A Zoogeographic and Ecological Review. Quarterly Review of Biology, Vol. 44: pp. 1-70.

Howell, D., B. Schropfer Roth. Sexual Reproduction in Agaves: The Benefits of Bats; The Costs of Semelparous Advertising. Ecology, Vol.62: pp.2-5.

Norberg, U., J. Rayner. Sept. 16, 1987. Ecological Morphology and Flight in Bats (Mammalia; Chiroptera): Wing Adaptations, Flight Performance, Foraging Strategy and Echolocation. Biological Sciences, Vol.316: pp.335-427.

Nowak, R. 1999. Walker Mammals of the World. Baltimore, London: Hopkins University Press.

Orr, R. 1960. An Analysis of the Recent Land Mammals. Systematic Zoology, Vol.9: pp.171-179.

Texas Parks and Wildlife, "Mexican Long-tongued Bat" (On-line). Accessed October 8, 2001 at http://www.tpwd.state.tx.us/nature/wild/mammals/bats/species/mex_long.htm.

Tuttle, M. "Mexican Long-tongued Bat" (On-line). Accessed october 8, 2001 at http://home.earthlink.net/~cmsquare/mexlngtg.html.