Craseonycteris thonglongyaibumblebee bat(Also: hog-nosed bat)

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Geographic Range

Bumblebee bats (Craseonycteris thonglongyai) are found in the Oriental Region of the world. They are found in Thailand, in the Bilauktaung mountain ranges in the western part of the country; Bumblebee bats are mainly located in the Sai Yoke, Kanchanaburi Province. They can also be found in the south eastern parts of Myanmar near the border with Thailand. (Humphery and Bain, 1990; Pearson and Beletsky, 2008)

Habitat

Bumblebee bats preferentially use limestone caves for roosting near the tops of the caves for warmth. Bamboo forests serve for the habitat in which they find their food. Bumblebee bats commonly forage in the upper canopy of the forest. (Hill and Smith, 1981; Humphery and Bain, 1990)

  • Other Habitat Features
  • caves

Physical Description

Bumblebee bats are about the size of a large bumblebee, hence the common name. These bats are considered among one of the smallest mammals in the world. The size of the head and body is 29 to 33 mm long. The length of the bumblebee bat forearms are 22 to 26 m, and adults weigh between 1.7 and 2.0 g. It also has small eyes that are mostly hidden by fur. Bumblebee bats have 28 teeth, which includes relatively large incisors. The lower incisors are long and narrow. The upper body of bumblebee bats can be 2 different colors: brownish red, or gray. The underside of the bat is a paler color while the wings and the membrane between the legs, called the uropatagium, are darker. (Hill and Smith, 1981; Nowak, 1999)

Bumblebee bats have a few distinct characters. First, bumblebee bats do not have a tail even though they have two caudal vertebrae. Their uropatagium are rather large. Their noses are pig-like, with large nostrils separated by a wide septum. Finally they also have large ears that are 9 to 10.2 mm long. The tragus is around half the size of the ears. Females have 2 sets of nipples, one on the chest and the other in the pubic area. The nipples in the pubic area are thought to be vestigial or not fully developed. The males have a large swelling in the gland that is at the base of their throats. The wings of bumblebee bats are long and wide, making them well adapted for hovering. They have thumbs that have claws. Their hindfoot is slender, narrow, and long. Nowak (1999) descirbed bumblebee bat skulls as small with a large inflated spherical braincase and lacking lambdoidal crests, postorbital processes, and supraoccipital ridges. In both genders a sagittal crest, which is a bone that runs down the top middle of the skull, is visible. The zygomata, which is the arch in the cheek, is described as slender but complete (Nowak 1999). (Hill and Smith, 1981; Nowak, 1999)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    1.7 to 2.0 g
    0.06 to 0.07 oz
  • Range length
    29 to 33 mm
    1.14 to 1.30 in

Reproduction

Little is known about the mating systems of bumblebee bats. (Nowak, 1999)

Bumblebee bats have one offspring per year and breed once per year in late April to May. However, little else is known about bumblebee bat reproduction. (Hayssen, et al., 1993; Huston, 2001; Nowak, 1999)

  • Breeding interval
    Bumblebee bats breed once yearly.
  • Breeding season
    Bumblebee bats breed in late April.
  • Average number of offspring
    1
  • Average time to independence
    1 years

While inside the cave offspring are usually found attached to the mother. While the mother is foraging the offspring is left alone. (Kurta and Kunz, 1987; Nowak, 1999)

Lifespan/Longevity

Bumblebee bat lifespans are unknown but it is thought to be around 5 to 10 years based on the lifespans of other closely related bats. (Ward, 2004)

Behavior

The behaviors of bumblebee bats are similar to species within the families Megadermatidae, Rhinopomatidae, Hipposideridae, and Rhinoolophidae. Bumblebee bats are a motile species which are capable of long powered flights. Bumblebee bats are normally active around dusk and dawn. The duration of dawn activity averages around 18 minutes while at dusk the average time is 30 minutes. When bats are not flying they are thought to be in torpor to conserve energy. Typically, about 100 individuals of this species will share the same cave. Despite this congregation, bumblebee bats are not social. Mothers will roost alone in the nursery cave. (Burton and Burton, 2002; Humphery and Bain, 1990; Huston, 2001; Nowak, 1999; Stenseth, 2000; Vaughn, et al., 2011)

Home Range

Bumblebee bats only fly about 1 km from the cave to forage. They do not maintain or defend territories. (Huston, 2001)

Communication and Perception

Bumblebee bats use echolocation to navigate their environment. They use sounds of a high intensity and have a constant frequency lasting as long as 2 ms followed by a shallow downward sweep lasting a duration of 1 ms. The beginning of the call has an upward sweep. The bats have a base frequency of 35 kHz. They also use two other harmonics. The second one is at 70 kHz and the third one, which is weaker, is at 105 kHz. Nothing is known about how the bats communicate within their roosts. (Hill and Smith, 1981; Surlykke, et al., 1993)

Food Habits

Insects are bumblebee bats main source of nutrition, but they also eat some spiders. They are aerial feeders, meaning they catch their prey while flying. They prefer to fly and forage along the tops of the bamboo trees. (Humphery and Bain, 1990; Huston, 2001; Ward, 2004)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

Currently, nothing is known about the predators of bumblebee bats.

Ecosystem Roles

Due to small numbers and small stature of bumblebee bats, its ecosystem impact on its prey is probably not substantial. (Huston, 2001)

Economic Importance for Humans: Positive

As insectivores bumblebee bats may help with pest control, but its impact is not considered substantial due to small population sizes. (Huston, 2001)

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

Bumblebee bats have no known negative effects on humans.

Conservation Status

Bumblebee bats are considered vulnerable on the IUCN Red List and endangered on the U.S. Endangered species list. The IUCN Redlist reports that the current population of 5100 individuals is decreasing. According to the IUCN Redlist, the species is disturbed by human activity in caves. This activity includes habitat-altering limestone extractions. Their foraging habitats are also being deforested, further decreasing prey availability. (Humphery and Bain, 1990; Ward, 2004)

Contributors

Alexandra Burns (author), Radford University, Karen Powers (editor), Radford University, Kiersten Newtoff (editor), Radford University, Melissa Whistleman (editor), Radford University, Laura Podzikowski (editor), Special Projects.

Glossary

acoustic

uses sound to communicate

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

crepuscular

active at dawn and dusk

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.

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.

female parental care

parental care is carried out by females

insectivore

An animal that eats mainly insects or spiders.

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.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

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.

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

tactile

uses touch to communicate

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.

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Brunet-Rossinni, A., S. Austad. 2004. Ageing studies on bats: A review. Biogerontology, 5/1: 211-222.

Burton, M., R. Burton. 2002. The International Wildlife Encyclopedia: Volume 3. Tarrytown, NY: Marshall Cavendish Corporation.

Hayssen, V., A. Tienhoven, A. Tienhoven, S. Asdell. 1993. Asdell's Patterns of Mammalian Reproduction: A Compendium of Species-specific Data. Ithaca, NY: Comstock Publishing Company.

Hill, J., S. Smith. 1981. Craseonycteris thonglongyai. Mammalian Species, 160/1: 1-4.

Humphery, S., J. Bain. 1990. Endangered Animals of Thailand. Gainsville, FL: Sandhill Crane Press.

Huston, A. 2001. Microchiropteran Bats: Global Status Survey and Conservation Action Plan. Newbury, UK: The Nature Conservation Bureau Ltd..

Kunz, T., M. Fenton. 2003. Bat Ecology. The University of Chicago: The University of Chicago Press.

Kurta, A., T. Kunz. 1987. Size of bats at birth and maternal investment during pregnancy. Symposia of the Zoological Society of London, 57/1: 79-106.

McCracken, G., G. Wilkinson. 2000. Bat Mating Systems. Waltham, MA: Academic Press.

Nowak, R. 1999. Walker's Mammals of the World Volume 2. Baltimore, MD: The Johns Hopkins University Press.

Pearson, D., L. Beletsky. 2008. Thailand. Northhampton, MA: Interlink Publishing Group.

Stenseth, N. 2000. Activity Patterns in Small Mammals: An Ecological Approach. Germany: Springer-Verlag Berlin Heidelberg.

Surlykke, A., L. Miller, B. Mohl, B. Andersen, J. Christensen-Dalsgaard, M. Jergensen. 1993. Echolocation in two very small bats from Thailand: Craseonycteris thonglongyai and Myotis siligorensis. Behavioral Ecology and Sociology, 33/1: 1-12.

Vaughn, T., J. Ryan, N. Czaplewski. 2011. Mammology. Sudbury, MA: Jones and Bartlett Publishers.

Ward, A. 2004. Pocket Factfiles; Endangered Animals. Toronto, Ontario, Canada: Andromeda Oxford Limited.