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)
- Terrestrial Biomes
- Other Habitat Features
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
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)
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- Breeding interval
- Bumblebee bats breed once yearly.
- Breeding season
- Bumblebee bats breed in late April.
- Average number of offspring
- Average time to independence
- 1 years
- Parental Investment
- female parental care
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)
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)
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)
- Communication Channels
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
- terrestrial non-insect arthropods
Currently, nothing is known about the predators of bumblebee bats.
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.
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)
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.
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.
an animal that mainly eats meat
uses smells or other chemicals to communicate
active at dawn and dusk
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.
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
An animal that eats mainly insects or spiders.
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.
found in the oriental region of the world. In other words, India and southeast Asia.
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
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
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