Animal Diversity Web

Ge­o­graphic Range

Chilona­talus tu­mid­ifrons (Ba­haman fun­nel-eared bats) is the only species of bat that is en­demic to the Ba­hamas. Cur­rently, Ba­haman fun­nel-eared bats are found on just two is­lands in the north­ern Ba­hamas: Great Abaco, and Watling (San Sal­vador). His­tor­i­cally they were also found on An­dros and other south­ern Ba­hamian is­lands. Post-glacia­tion cli­mate changes such as raised sea lev­els and dis­rupted ther­mal ecol­ogy are con­sid­ered the largest con­trib­u­tor to the shrink­ing range of this species. Some human im­pacts may also have played a role. (Dalquest, 1950)

• Biogeographic Regions
• neotropical
  • native

• Other Geographic Terms
• island endemic

Habi­tat

Ba­haman fun­nel-eared bats are found ex­clu­sively in Ba­hamian dry-de­cid­u­ous forests. The for­est found on Great Abaco is more lush and has a taller over story than the low scrubby for­est type which dom­i­nates much of Watling. Deep caves, where hot and moist con­di­tions are main­tained con­tin­u­ously, are the sin­gle most im­por­tant habi­tat re­quire­ment. These caves pro­vide C. tu­midrifrons with nec­es­sary roost­ing habi­tat. Dur­ing their ac­tive hours Ba­haman fun­nel-eared bats for­age for in­sects in the dense un­der­story of sur­round­ing forests. (Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005; Miller, 1903)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• scrub forest

• Other Habitat Features
• caves

• Range elevation

  300 (high) m

  984.25 (high) ft

Phys­i­cal De­scrip­tion

Chilona­talus tu­mid­ifrons is sim­i­lar in ap­pear­ance to its close rel­a­tive Chilona­talus mi­cro­pus, Cuban fun­nel-eared bats. How­ever, Ba­haman fun­nel-eared bats are slightly larger than Cuban fun­nel-eared bats. The fur is red­dish to chest­nut brown dor­sally and pale yel­low on the ven­tral sur­face. There is no ev­i­dence of sex­ual di­mor­phism in Ba­haman fun­nel-eared bats. The wings are rel­a­tively long and nar­row, their thumbs are short, and al­most com­pletely en­veloped in the skin of the wing. (Dalquest, 1950; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005; Koop­man, et al., 1957)

Species in the fam­ily Na­tal­i­dae are named for their char­ac­ter­is­tic large, fun­nel-like ears. The ex­ter­nal ear is cov­ered in small glan­du­lar papil­lae. A spe­cial char­ac­ter­is­tic of male na­tal­ids is known as the “na­talid organ”. Lo­cated near the base of the muz­zle, it is a rounded pro­jec­tion made up of sen­sory cells. The exact func­tion of the organ is un­known, but it is spe­cific to na­tal­ids. The tip of the nose is capped with a small, fleshy tra­gus that is not con­sid­ered a true nose­leaf. The frag­ile skull is elon­gate, with a swollen brain­case and a nar­row, tubu­lar ros­trum.

Den­tal for­mula: 2/3; 1/1; 3/3; 3/3 (Dalquest, 1950; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005; Koop­man, et al., 1957)

• Other Physical Features
• endothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes alike

• Range mass

  4 to 7 g

  0.14 to 0.25 oz

• Range length

  8 to 11 cm

  3.15 to 4.33 in

• Range wingspan

  7 to 9 cm

  2.76 to 3.54 in

Re­pro­duc­tion

Noth­ing is known of the re­pro­duc­tion or mat­ing sys­tems of Ba­haman fun­nel-eared bats, but they are most likely polyg­y­nous. (Buden, 1987; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005)

• Mating System
• polygynous

Lit­tle in­for­ma­tion is avail­able on the gen­eral re­pro­duc­tive be­hav­ior of Ba­haman fun­nel-eared bats. Mem­bers of the fam­ily Na­tal­i­dae char­ac­ter­is­ti­cally give birth to a sin­gle young to­wards the end of the dry sea­son. Fe­males gather in ma­ter­nity colonies to give birth to and raise their young. Off­spring are rel­a­tively large, often close to 50% of their moth­ers’ weight. The closely re­lated Mex­i­can fun­nel-eared bat (Na­talus stramineus) breeds dur­ing the late dry sea­son and has a ges­ta­tion pe­riod of about 10 months. (Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005; Koop­man, et al., 1957)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• viviparous

• Breeding interval

  Bahaman funnel-eared bats breed once yearly.

• Breeding season

  Birth occur in the late dry season, suggesting that mating occurs after the late dry season.

• Range number of offspring

  1 to 1

• Average gestation period

  10 months

Fe­male Ba­haman fun­nel-eared bats form ma­ter­nity colonies in which they give birth to and care for their young. Fe­males are com­pletely re­spon­si­ble for the care of their young. Giv­ing birth to just one off­spring per event means that fe­males al­lo­cate all of their ef­forts to the sin­gle young. (Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005)

• Parental Investment
• altricial
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

Noth­ing is known of the longevity/lifes­pan of Ba­haman fun­nel-eared bats.

Be­hav­ior

Ba­hamian fun­nel-eared bats are noc­tur­nal. Gen­er­ally colonies of Ba­haman fun­nel-eared bats leave their roost 30 min­utes after sun­down. Agile fly­ers, they are able to for­age among dense fo­liage for their in­sect prey. The most in­tense for­ag­ing ac­tiv­ity among na­tal­ids oc­curs about two hours after leav­ing the roost. Ba­haman fun­nel-eared bats are such agile fly­ers that they are rarely caught in mist nets. For this rea­son, lit­tle is know about their nat­ural his­tory. (Buden, 1987; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005)

• Key Behaviors
• troglophilic
• flies
• nocturnal
• motile
• social
• colonial

Home Range

Noth­ing is specif­i­cally known about the home range of Ba­haman fun­nel-eared bats. Their home ranges are likely cen­tered around their roost­ing caves. (Buden, 1987; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005)

Com­mu­ni­ca­tion and Per­cep­tion

Mem­bers of the fam­ily Na­tal­i­dae echolo­cate using high fre­quency pulses, up to 170 kHz. This gives them a de­tailed pic­ture of their en­vi­ron­ment. Whether Chilona­talus tu­mid­ifrons is a nasal or oral emit­ting bat is still un­known. All fun­nel-eared bats have, as the name sug­gests, very large, fun­nel-shaped ears. These allow them to de­tect faint sounds and re­turn echoes from their echolo­ca­tion pulses. The ears of these bats are cov­ered in small papil­lae, which may in­crease au­di­tory sen­si­tiv­ity. Like other mam­mals, they are likely to use ol­fac­tory and tac­tile cues in com­mu­ni­ca­tion as well. (Dalquest, 1950; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005)

• Communication Channels
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• echolocation
• chemical

Food Habits

Chilona­talus tu­mid­ifrons feeds ex­clu­sively on fly­ing in­sects. (Dalquest, 1950; Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005; Koop­man, et al., 1957; Miller, 1903)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects

Pre­da­tion

No preda­tors of Ba­haman fun­nel-eared bats have been recorded. Being ac­tive at night re­duces their ex­po­sure to di­ur­nal preda­tors. As with most bat species, owls and climb­ing snakes may pose a threat to adults in flight and roost­ing an­i­mals, re­spec­tively. (Dalquest, 1950; Miller, 1903)

• Anti-predator Adaptations
• cryptic

Ecosys­tem Roles

In­sec­tiv­o­rous bat species, such as Ba­haman fun­nel-eared bats, can have an enor­mous ef­fect on in­sect pop­u­la­tions in the vicin­ity of their colonies. Many in­sects that bats prey on are agri­cul­tural pests, mak­ing them highly ben­e­fi­cial to agri­cul­ture.

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Ba­haman fun­nel-eared bats eat in­sect pests.

• Positive Impacts
• controls pest population

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

Chilona­talus tu­mid­ifrons has no neg­a­tive eco­nomic im­pact on hu­mans.

Con­ser­va­tion Sta­tus

Ba­haman fun­nel-eared bats are listed as "vul­ner­a­ble" under the IUCN's stan­dards for threat­ened species. ("IUCN The World Con­ser­va­tion Union", 1995)

• IUCN Red List

  Near Threatened
  More information

• IUCN Red List

  Near Threatened
  More information

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

These bats were pre­vi­ously rec­og­nized as Na­talus tu­mid­ifrons.

Con­trib­u­tors

Tanya Dewey (ed­i­tor), An­i­mal Di­ver­sity Web.

Steven Burns (au­thor), Uni­ver­sity of Wis­con­sin-Stevens Point, Chris Yahnke (ed­i­tor, in­struc­tor), Uni­ver­sity of Wis­con­sin-Stevens Point.

Ref­er­ences

In­ter­na­tional Union for Con­ser­va­tion of Na­ture and Nat­ural Re­sources. 1995. "IUCN The World Con­ser­va­tion Union" (On-line). Ac­cessed No­vem­ber 26, 2006 at http://​www.​iucn.​org/​themes/​ssc/​redlist.​htm.

Buden, D. 1987. A Guide to the Iden­ti­fi­ca­tion of the Bats of the Ba­hamas. Car­ribean Jour­nal of Sci­ence, 23: 362-367.

Dalquest, W. 1950. The Gen­era of the Chi­ropteran Fam­ily Na­tal­i­dae. Jour­nal of Mam­mal­ogy, 31: 436-443.

Grz­imek's An­i­mal Life En­cy­clo­pe­dia, 2005. "Answers.​com" (On-line). Ac­cessed Oc­to­ber 22, 2006 at http://​www.​answers.​com/​topic/​bahamian-funnel-eared-bat.

Koop­man, K., M. Hecht, E. Lidecky-Janecek. 1957. Notes on the Mam­mals of the Ba­hamas with spe­cial ref­er­ence to bats. Jour­nal of Mam­mal­ogy, 38: 164-174.

Miller, G. 1903. The mam­mals of the An­daman and Nico­bar Is­lands. Pro­ceed­ings of the United States Na­tional Mu­seum, 24: 751-795.