Geographic Range
Cuban lesser funnel-eared bats (
Chilonatalus micropus
) are found across Jamaica, though most frequently observed in three caves (Oxford,
St. Clair, and Windsor). They have also been observed, though less abundantly, on
Hispaniola (Dominican Republic and Haiti) and on the Colombian islands of San Andrés
and Providencia.
- Biogeographic Regions
- neotropical
- Other Geographic Terms
- island endemic
Habitat
Cuban lesser funnel-eared bats are obligate cave roosters, and have been found in
21 terrestrial caves of various sizes, though mostly in caves that are small and isolated.
These caves tend to be warm, with high humidity, and relatively high concentrations
of carbon dioxide and hydrogen sulfide. Cuban funnel-eared bats require an environment
with fairly stable humidity. Though
C. micropus
appears to be able to tolerate variations in roost temperature, they have adapted
to the warm environment of tropical caves, as this is the only habitat type with a
sufficient and stable enough humidity. It is possible that the obligate cave roosting
lifestyle of
C. micropus
has evolved due to the frequency of hurricanes in the Caribbean region, as cave roosting
individuals would be more likely to survive a hurricane than exposed bats, such as
those that dwell in trees.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- rainforest
- Other Habitat Features
- caves
Physical Description
Cuban lesser funnel-eared bats are perhaps the smallest of their genus. Records of
adult male specimens collected reported weights ranging from 2.30 to 3.32 g, and adult
female specimens collected had weights ranging from 2.80 to 2.88 g. The head-body
length of
C. micropus
ranges from 38 to 45 mm, with a tail length ranging from 45 to 48 mm. Their hind
legs measure 7 to 8 mm in length, with the tail extending as long as, or longer than
the legs. The tail extends to the posterior end of the uropatagium, but never beyond
this membrane. Forearms of
C. micropus
have been measured between 31.0 and 35.7 mm. Individuals from different regions vary
in measurements, with Jamaican individuals measuring larger, on average, in most measurements
taken. There is some degree of sexual dimorphism in the size of
C. micropus
, with females being described as larger. Lengths of female skulls, crania, forearms,
and third metacarpals exceeded those of males, though males had larger and broader
brain cases.
Individuals of
C. micropus
have a pelage that is fine and soft, but densely packed. Individual hairs are considered
long, from 3 to 7 mm. The dorsal surface of Cuban lesser funnel-eared bats tends to
appear pale brownish yellow, with bicolored hairs that are lighter at the roots, and
darken to a reddish brown color at the tips. The ventral fur is often a slightly darker
pale yellow brown, though both dorsal and ventral fur have been described as light
greyish brown. Thicker hairs curve along the lateral edges of the upper lip and are
"moustache-like" in appearance. Thin, sparse hairs occur along the posterior edge
of the uropatagium.
All adult males of
C. micropus
have a rounded, glandular-like organ on their head. This organ is found in all species
of, and only in the family
Natalidae
, and is most prominent in the
Chilonatalus
genus. The appearance and placement of this organ on the head is useful in distinguishing
one species from another. In Cuban lesser funnel-eared bats this organ is nearly naked,
hemispherical in shape, and medium to large sized, (approximately 2.5 mm diameter).
This organ is found in Cuban lesser funnel-eared bats on the dorsal surface of the
head, where the brain case meets the rostrum, between the eyes, and near the anterior
bases of the ears. The function of this organ is not fully understood, though it does
contain some sensory-like cells and is thought to have some kind of glandular function.
Many facial features used to describe
C. micropus
are common to the entire family or genus. In the genus
Chilonatalus
, the pararhinal glands on the anterior tip of the muzzle are relatively large and
well developed, so much so that the projections form a primitive nose leaf-like structure
that appears as a small, hairy projection on the dorsal tip of the snout and forces
the nostrils forward. Nostrils open ventrolaterally in an elliptical shape. Despite
the similarities found within the family and genus, facial features are important
for distinguishing differences among
Natalidae
species. In Cuban lesser funnel-eared bats, the muzzle is tipped up, and the upper
lip is slightly thickened. The lower lip is noteably thick, fleshy and well developed.
Below the lower lip is a small, transverse, ridge-like projection, creating a distinguished
"groove" below the mouth. This trait is present in some similar species, but is most
pronounced in
C. micropus
.
The ears of
C. micropus
are large, and lack prominent ridges (3 subtle ridges may be visible). The pinnae
are relatively long (11.4 to 15.0 mm) and funnel shaped, hence its common name. The
tips of the ears are anteriorly truncated at a 30 degree angle relative to the posterior
edge of the ear. The ear narrows laterally towards the distal end (more so than in
other species of the same genus), resulting in concave pinnae with slightly pointed
distal ends. The widened bases attach to the dorsal surface of the head along a curved
margin, just above the eyes. The medial edge of each pinna is relatively straight,
while the lateral edge presents as more concave, and is deeply notched. The conch
is rounded and projects forward. The tragus is short and twisted in a helical form.
Eyes are small and not prominent.
The skull of
C. micropus
is elongate with a narrow, dorsoventrally flattened rostrum that tips up at the distal
end and is longer than that of other species of the genus. The brain case is rounded
and rises abruptly from the rostrum. A sagittal crest is present, though poorly developed.
The zygomatic arch is complete and thin. The skull length is less than that of other
species within the genus, and has been recorded between 13.5 and 14.7 mm. Dentition
varies to some degree between species within the genus and can be used as a distinguishing
factor. Cuban lesser funnel-eared bats has 38 teeth and the dental formula is as follows:
I 2/3 C 1/1 P 3/3 M 3/3. The upper incisors are long and pointed, with the two outer
ones being either smaller, or of similar size relative to the inner ones. Upper incisors
are paired, with a wide space between the pairs, and a separation from the canines.
The lower incisors are well developed. The upper premolars are not crowned, and the
first premolars are slightly smaller than the second. The molars have relatively broad
cusps. The palatal region may also help to distinguish Cuban lesser funnel-eared bats
from other species as it has nine palatal ridges, five of which are divided, while
the remaining four are continuous across the palate.
The ribs of
C. micropus
are fused together, and fused to the sternum with sutures visible. The ribs and sternum
come together to form a bell-shaped structure. Vertebrae C7 to T3 are fused, as well
as those of T11 to L5. The location of the attachment of the wing membrane to the
leg differs among species. In Cuban lesser funnel-eared bats, the wings attach to
the legs where the middle and distal thirds of the tibia meet. The tibia is approximately
half the length of the forearm. The wings of Cuban lesser funnel-eared bats are relatively
long and wide, with a long, thin calcar that runs along two thirds of the edge of
the uropatagium.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- female larger
Reproduction
Research on the reproductive system and behaviour of
C. micropus
is lacking.
Individuals of the species possess 36 chromosomes (18 pairs) and may have low genetic
variability. Genetic material does not differ greatly from other members of the genus.
A precise breeding season and time to weaning is unknown, but lactation appears to
end in July. This speculation is based on samples of females collected throughout
July where up to 90% were lactating, as compared to a sample collected at the end
of July that was entirely reproductively inactive. The species is known to have prominent
nipples and mammary tissue in females, and long penises in males. The baculum is smaller
than other members of the genus, and is slightly wider at the base than it is through
the short, straight shaft. The tip of the baculum curves slightly downward.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
Research on the reproductive system and behaviour of C. micropus is lacking. Like other bats, young of this species is cared for by mothers until independence.
- Parental Investment
- female parental care
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
provisioning
Lifespan/Longevity
The generation length of
C. micropus
is listed as 5 years by the IUCN, but another source (Pacifici et al., 2014) declares
the species specific generation length for Cuban lesser funnel-eared bats to be unknown,
while noting an average generation length of 5.67 years for
o.Chiroptera
individuals of similar mass.
Behavior
Cuban lesser funnel-eared bats are an obligate cave roosting species. They roost in
groups on the ceilings of caves, spaced about 7 to 10 cm apart. They seem to prefer
recessed or protected areas, such as the undersides of ledges, though they have also
been observed roosting in open areas of caves. Some groupings observed consisted of
10 to 20 individuals, while others were estimated to be up to several hundred. It
is unknown why
C. micropus
is an obligate cave rooster, though a closely related species found in the same region,
Natalus major
, loses water to the environment easily through their thin wing membranes. This results
in dehydration, which may explain why these species are restricted to humid caves.
In some instances,
C. micropus
has been observed roosting amongst other bat species, though the species tend to
separate into aggregates of conspecifics when disturbed by humans. One observed group,
seemingly disturbed by human presence, flew in close proximity to one another. It
is speculated that this type of behavior may be an anti-predator response, though
there is not enough information to definitively say that it is not a typical behavior
of the species. Individuals have also been observed flying low, within one meter of
the cave floor, and near the cave walls. Again, the presence of humans may or may
not have affected their flying behavior. Additionally, Cuban lesser funnel-eared bats
are a slow flyer relative to other bats, and are active at night.
Home Range
The home range of
C. micropus
is restricted to the island caves mentioned in the above sections on geographic range
and habitat. There is no evidence at this time suggesting they leave their cave habitat
for any extended period of time.
Communication and Perception
Cuban lesser funnel-eared bats are believed to use echolocation to navigate and perceive
insect prey in their environment. It is likely that they do this with two frequencies
between 40 and 80 kHz, though research in this area is limited.
- Perception Channels
- tactile
- acoustic
- ultrasound
- echolocation
- chemical
Food Habits
While research is lacking in this area, there is evidence that
C. micropus
is an insectivore, like other members of the family
Natalidae
. Lysosome-like activity has been found in the salivary glands of Cuban lesser funnel-eared
bats, which may function to breakdown chitin in the exoskeletons of insects consumed
as food. Cuban funnel-eared bats are also known echo-locators, likely using harmonics
to hunt for insects in the dark.
- Primary Diet
- carnivore
- Animal Foods
- insects
Predation
Information on predators is not reported in the literature. Nocturnal habits and selection of roosts in most bats is an effective form of anti-predation behaviour.
Ecosystem Roles
Cuban lesser funnel-eared bats have been observed roosting among groups of other bat
species, and roosting separately with only conspecifics. Some species they have been
found roosting with include
Mormoops blainvillii
,
Pteronotus parnellii
,
Pteronotus macleayi
,
Macrotus waterhousii
,
Monophyllus redmani
,
Artibeus jamaicensis
,
Pteronotus fuliginosa
,
Erophylla sezekorni
,
Phyllonycteris aphylla
, and
Natalus major
. It is unknown if
C. micropus
plays any significant role in the ecology of these groups, or the caves in which
they reside. It is possible that Cuban lesser funnel-eared bats play some role in
controlling insect populations, as they are thought to be insectivores.
Economic Importance for Humans: Positive
Cuban lesser funnel-eared bats may prove an enlightening mammalian research subject,
particularly in the field of evolutionary biology due to its limited distribution
and small size relative to other mammals. On Hispaniola, farmers collect bat feces
from caves to use in manure based fertilizer, called guano. Some of the islands where
C. micropus
is found are popular tourism destinations, and recreational activities do occur within
the caves where they live.
- Positive Impacts
- ecotourism
- research and education
- produces fertilizer
Economic Importance for Humans: Negative
There are no known adverse effects of C. micropus on humans.
Conservation Status
The International Union for Conservation of Nature (IUCN) has listed
C. micropus
as vulnerable due to a decline in population of about 30% over three generations.
Possible explanations for this decline include population isolation as well as a decline
in critical habitat. Populations of Cuban lesser funnel-eared bats are fragmented
across 4 islands, 2 of which are very small and near human populations which may be
detrimental to the bats. Any threats posed to the caves where they live, respectively
threaten the bats. Threats to caves include residential and commercial development,
mining, tourism, recreation and feces collection by farmers. These activities may
put stress on the species, disrupt its behavior, or degrade its habitat. Feral cats
have also been known to feed on Cuban lesser funnel-eared bats in Jamaica, where the
only known large population of the species exists. Extirpation of
Natalidae
from some Bahamian islands has been attributed to environmental changes resulting
in loss of required microclimates.
Conservation efforts should focus on protecting the habitat of Cuban lesser funnel-eared
bats. Protecting the caves where they reside is believed to be the best way to protect
the species. More detailed research is needed to determine appropriate monitoring
efforts and management strategies. This species has not been well researched despite
the fact that they are known to exist in such large groups. Research efforts may have
proven difficult for several reasons. There has not been a great deal of bat research
in the geographic range of
C. micropus
. This may be party due to the hot humid conditions of the caves they are found in,
which has been described as uncomfortable to humans. These bats are also very small
and difficult to capture in mist nets, though they have been easily captured using
hand nets. Lastly, they may have very narrow ecological requirements which may be
hard to duplicate, making them difficult to keep live in captivity.
Other Comments
The phylogeny of
C. micropus
has been debated over the years.
Chilonatalus
was previously considered to be a subgenus within the genus
Natalus
, but it is now accepted to be its own genus, and sister taxa to the genus
Natalus
. The genus
Chilonatalus
is monophyletic, and contains three species:
C. macer
,
C. tumidifrons
, and
C. micropus
. The closest relative to Cuban lesser funnel-eared bats is
C. tumidifrons
.
The etymology of
Natalus
(the genus in which Cuban lesser funnel-eared bats were originally placed) is derived
from a Latin word meaning "related to one's birth". This is presumably a reference
to the small size of the bat, and their resemblance to newborns. The specific epithet,
micropus, means "small foot".
Additional Links
Contributors
Michelle Packer (author), University of Manitoba, Annemarie van der Marel (editor), University of Manitoba, Tanya Dewey (editor), University of Michigan-Ann Arbor.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- island endemic
-
animals that live only on an island or set of islands.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- 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
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- female parental care
-
parental care is carried out by females
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- 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.
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- ultrasound
-
uses sound above the range of human hearing for either navigation or communication or both
- echolocation
-
The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.
- chemical
-
uses smells or other chemicals to communicate
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- 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.
- 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.
References
Black, C., P. Bryan, D. Buisseret, J. Ferguson. 2019. "Jamaica" (On-line). Encyclopedia Brittanica. Accessed October 27, 2019 at https://www.britannica.com/place/Jamaica .
Buden, D. 1987. A Guide to the Identification of the Bats of the Bahamas. Caribbean Journal of Science , 23/3-4: 362-364. Accessed October 27, 2019 at https://80d3fb63-a-62cb3a1a-s-sites.googlegroups.com/site/projecteleuthera/file-cabinet/Bahamas_bat_identification_guide.pdf?attachauth=ANoY7cqK-kqw1bDZN6UFOKXFVRNyyvgxhuDd_9U3PW1-__K3CX2fM3CSbqHENkS6aQB4TUJGSL812AZVdg0NnKNf1Sx4fHH3q0ixyLM6HaTh2nQUlyalTb6-zUzV_L1swL_vdrh_-iaf7s0RrY8BYvg5OV_ZBMklqQECvcJBb8FMYnOTFOA3VRT8goF7zM00oKxE-xyDsWRVEa3KxWQw47iilhZrcALyVBL34rdtKVrNuoyZhvjd_uuDMEvydAm7oDgDIWzsl2ftOTu-6ZN4Zg-02fdz_HMZbw%3D%3D&attredirects=1 .
Dalquest, W. 1950. The genera of the Chiropteran family Natalidae. Journal of mammology , 31/4: 436-443. Accessed October 29, 2019 at https://www-jstor-org.uml.idm.oclc.org/stable/pdf/1375114.pdf?refreqid=excelsior%3Ae0f3fb4b34ea5aa782f228c1d89dbc78 .
Dávalos, M. 2005. Molecular phylogeny of Funnel-eared bats (Chiroptera: Natalidae), with notes on biogeography and conservation. Molecular Phylogenetics and Evolution , 37/1: 91-103. Accessed October 27, 2019 at https://pdf.sciencedirectassets.com/272322/1-s2.0-S1055790305X01063/1-s2.0-S1055790305001612/main.pdf?X-Amz-Security-Token=IQoJb3JpZ2luX2VjEGEaCXVzLWVhc3QtMSJGMEQCIDkKLpG0FOVxTd2NqJmU1kzNiyb9B9Qiz4ApVlBjad4YAiBzNmXpKKOUHKqOH5i5ocV1li5r1gCB3taVkwKejw%2BEEirZAgia%2F%2F%2F%2F%2F%2F%2F%2F%2F%2F8BEAIaDDA1OTAwMzU0Njg2NSIMKLZDzSZ5KXqEzHBEKq0CfrnnJQiTOQKjV5LGfjM4KAmFnHlaKOtLm%2BqV7ZSL7nXQkxx8eyum1OpvKA3wNm4KOP8mvuW3V7gXvK3JcNX2RUq%2B7Bqt0V%2FhrUmvdOFXGyp6YP%2B4HgmY%2BbMnUsVfPzZhM1VK0iu4aRpcvh%2FQreTKUbnfZ7u2Oh23fAgdsghtZu%2BbTR0AjBB%2B7IHD8gzqL8LCrWwKlye%2F2TXapqh77DPydzDr%2Blsr52ITDQLyiU7cJg6hUq%2B3hdS13JwtvfN8vgMNnwioJnW4X%2FhXZ65k1nhRg65ZKvAUaU9vg5PoPR%2FcCZNRXJlO3d1z93I7GcytRmxCmBUGpqHlqQXyVFCYMiCxvAb004063nfTM1HFyhDcyINKnJSLglOO%2FBR4oAFRE94WBprsszEHRDuLXMmpJTCrrfzuBTrQAlN%2BF0psWGz2YEfzJiXh66FzKA3IxzlNR91Xprf%2B7PbEkB4nZmpBM7G33CE%2FniRzgaoFz8bdKCb7rsQEeAEPTUsFF7VXs7RONMQfBxHbdHwaTihAnECUThTD0%2B34ArnLmmV4gjqwzx5ObtduzPg7ZojPOJt08vhr8XGj%2F0pGpiJd2GMkUZP%2BdCItL0GCZKmZC%2FDohpB8NLUKP9d4iHJQLHYtX29Kn4WJ0PMvddOipz23dfTuxdXDx1PMJT4dKdhZVaj0xNFaY1d8EMIMlrypoekfxE1Eu6ImJOOlwOR4kPBMUE3%2BLuy3mbjNZgPDJCC6s%2BauWgKjg6GXG4Sjxvyx%2BenMtgkro2wpeX7IF6jxfK113ANwN7w0ip3s%2F4Nl%2BWOgK7rlmWq2742Mk5%2Bv1T7U5hmhGmRfSGeR80DNlDpMBksL1e4eSTLM9xqQ4uvEidMq6A%3D%3D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20191128T010853Z&X-Amz-SignedHeaders=host&X-Amz-Expires=300&X-Amz-Credential=ASIAQ3PHCVTY3QNI7G5I%2F20191128%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Signature=484d5e7f412f4d059900f23cb88c74f722e97144f2c6cb0550002376262fef51&hash=513fc72beb028cae44dd1d118e876db3d839855d0ea5bc2cd0b9cd79283c8da9&host=68042c943591013ac2b2430a89b270f6af2c76d8dfd086a07176afe7c76c2c61&pii=S1055790305001612&tid=spdf-a449de24-8530-4dbb-9c42-87fda8477fe0&sid=b7ea11c410e6e245755b71d087b472587560gxrqa&type=client .
Genoways, H., R. Baker, J. Bickham, C. Phillips. 2005. Bats of Jamaica . Texas Tech University: Special Publications of the Museum of Texas. Accessed October 29, 2019 at https://www.researchgate.net/publication/228906680_Bats_of_Jamaica .
González, N., H. Wiarda. 2019. "Dominican Republic" (On-line). Encyclopedia Brittanica. Accessed October 27, 2019 at https://www.britannica.com/place/Dominican-Republic .
Hoyt, A., R. Baker. 1980. Natalus major. Mammalian Species , 130: 1-3.
Kerridge, D., R. Baker. 1978. Natalus micropus. Mammalian Species , 114/29: 1-3. Accessed November 12, 2019 at https://doi.org/10.2307/3503927 .
Miller, G. 1899. History and characters of the family Natalidae. Bulletin of the American Museum of Natural History , 12/18: 245-253.
Morgan, G., N. Czaplewski. 2003. A new bat (Chiroptera: Natalidae) from the Early Miocene of Florida, with comments on Natalid phylogeny. Journal of Mammalogy , 84/2: 729-752.
Ottenwalder, J., H. Genoways. 1982. Systematic review of the Antillean bats of the Natalus micropus-complex (Chiroptera: Natalidae). Mammalogy papers , 251/5-6: 17-37.
Pacifici, M., L. Santini, M. Di Marco, D. Baisero, L. Francucci, G. Grottolo Marasini, P. Visconti, C. Rondinini. 2013. Generation length for mammals. Nature Conservation , 5: 87-94.
Parsons, J., C. Garavito, W. McGreevey, H. Kline, R. Gilmore. 2019. "Colombia" (On-line). Encyclopedia Britannica. Accessed October 27, 2019 at https://www.britannica.com/place/Colombia .
Solari, S. 2018. "Chilonatalus micropus" (On-line). The IUCN Red List of Threatened Species. Accessed September 25, 2019 at http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T88088852A22040831.en. .
Tejedor, A. 2011. Systematics of funnel-eared bats (Chiroptera: Natalidae). American Museum of Natural History , 353: 26-39.