Ban Sai Yoke, Kanchanaburi Province, Southwestern Thailand
Biogeographic Regions: oriental (Native )
The size of a large bumblebee, Craseonycteris thonglongyai may be the world's smallest mammal. Its head and body length ranges from 29 to 33 mm, and its forearm ranges from 22 to 26 mm. One of C. thonglongyai's most distinctive features is its pig-like muzzle, which is swollen around the nostrils and chin. The wide, crescent-shaped nostrils open directly in the face of the nose pad, which is formed by the wide septum. Another distinct trait is C. thonglongyai's lack of a tail, despite the presence of two caudal vertabrae. The upper side of the body is either brown to red or grey. The underside is generally paler, while the wings and interfemoral membrane are dark. Bats of this species have small eyes, which are mainly concealed by fur, and large ears. The tragus is almost one half the length of the ear, narrow at its base and widest at its middle. A glandular swelling at the base of the throat is found in a males, who also has a relatively large penis. A female has a pair of pectoral nipples and a pair of vestigial pubic nipples. The long and wide wings have a tip adapted for hovering. The propatagium is broad, the thumb short with a well-developed claw, and the hindfeet are long and narrow. Craseonycteris thonglongyai has a dental formula of 1/2 1/1 1/2 1/3. Its upper incisors are large, and its lower incisors are tricusped, with the middle cusp dominant (Nowak and Paradiso, 1983). Koopman (1984) describes them as normal insectivorous-type teeth.
The skull is small with an inflated and globose braincase, prominent sagittal crest, slender zygomatic arch and large, flat bullae. It lacks a postorbital process (Nowak and Paradiso, 1983). The premaxillaryi is separate from the surrounding bones. The nasal branch, which is fused posteriorly and lies on the nasals and maxillae, is more developed than the palatal branch. The palatal branch is fused anteriorly and posteriorly, forming a large vacuity (Lawlor, 1979). Its postcranial sketelon varies from other bats in that its second manal digit has a single bony digit. It has a threadlike fibula, a weak pelvis, and extremely fused sacral vertebrae (Koopman, 1984). Craseonycteris thonglongyai also lacks a calcar (Nowak and Paradiso, 1983).
Habitat and Ecology
Craseonycteris thonglongyai dwells far from the entrance, deep in the most remote, small limestone caves (Nowak and Paradiso, 1983). These caves are located in a previously forested area, which had been completely clearcut in the 1950's and is now dominated by teak plantations (Macdonald, 1984).
Craseonycteris thonglongyai is an insectivorous bat. It appears to feed at night by gleaning on foliage, taking in the small arthropods that rest on the tops of bushes and trees (Nowak and Paradiso, 1983). Diptera make up approximately 80% of its diet, with Hymenoptera and occasional Psocoptera comprising a much smaller portion (Nabhitbhata, 1982).
Animal Foods: insects
Primary Diet: carnivore (Insectivore )
Life History and Behavior
There is no information on the reproductive system of this species. Members of the most closely related families, Rhinopomatidae and Emballonuridae, typically have one young per litter and one litter per year. Breeding systems vary greatly between these families (Lawlor, 1979).
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Endangered(Baillie and Groombridge 1996)
- 1994Rare(Groombridge 1994)
- 1990Rare(IUCN 1990)
- 1988Rare(IUCN Conservation Monitoring Centre 1988)
- 1986Insufficiently Known(IUCN Conservation Monitoring Centre 1986)
Date Listed: 01/23/1984
Lead Region: Foreign (Region 10)
Where Listed: Entire
Population location: Entire
Listing status: E
For most current information and documents related to the conservation status and management of Craseonycteris thonglongyai , see its USFWS Species Profile
Craseonycteris thonglongyai is endangered and rare, a CITES list animal. The total population is estimated at two hundred individuals.
IUCN Red List of Threatened Species: vulnerable
Kitti's hog-nosed bat
Kitti's hog-nosed bat (Craseonycteris thonglongyai), also known as the bumblebee bat, is a vulnerable species of bat and the only extant member of the family Craseonycteridae. It occurs in western Thailand and southeast Burma, where it occupies limestone caves along rivers.
Kitti's hog-nosed bat is the smallest species of bat and arguably the world's smallest mammal. It has a reddish-brown or grey coat, with a distinctive pig-like snout. Colonies range greatly in size, with an average of 100 individuals per cave. The bat feeds during short activity periods in the evening and dawn, foraging around nearby forest areas for insects. Females give birth annually to a single offspring.
Although the bat's status in Burma is not well known, the Thai population is restricted to a single province and may be at risk for extinction. Its potential threats are primarily anthropogenic, and include habitat degradation and the disturbance of roosting sites.
Kitti's hog-nosed bat is about 29 to 33 mm (1.1 to 1.3 in) in length and 2 g (0.071 oz) in mass, hence the common name of "bumblebee bat". It is the smallest species of bat and may be the world's smallest mammal, depending on how size is defined. The main competitors for the title are small shrews; in particular, the Etruscan shrew may be lighter at 1.2 to 2.7 g (0.042 to 0.095 oz) but is longer, measuring 36 to 53 mm (1.4 to 2.1 in) from its head to the base of the tail.
The bat has a distinctive swollen, pig-like snout with thin, vertical nostrils. Its ears are relatively large, while its eyes are small and mostly concealed by fur. Its teeth are typical of an insectivorous bat. The dental formula is 1:1:1:3 in the upper jaw and 2:1:2:3 in the lower jaw, with large upper incisors.
The bat's upperparts are reddish-brown or grey, while the underside is generally paler. The wings are relatively large and darker in colour, with long tips that allow the bat to hover. Despite having two caudal vertebrae, Kitti's Hog-nosed Bat has no visible tail. There is a large web of skin between the hind legs (the uropatagium) which may assist in flying and catching insects, although there are no tail bones or calcars to help control it in flight.
Range and distribution
Kitti's hog-nosed bat occupies the limestone caves along rivers, within dry evergreen or deciduous forests. In Thailand, Kitti's hog-nosed bat is restricted to a small region of the Tenasserim Hills in Sai Yok District, Kanchanaburi Province, within the drainage basin of the Khwae Noi River. While the Sai Yok National Park in the Dawna Hills contains much of the bat's range, some Thai populations occur outside the park and are therefore unprotected.
Since the 2001 discovery of a single individual in Burma, at least nine separate sites have been identified in the limestone outcrops of the Dawna and Karen Hills outside the Thanlwin, Ataran, and Gyaing Rivers of Kayin and Mon States. The Thai and Burmese populations are morphologically identical, but their echolocation calls are distinct. It is not known whether the two populations are reproductively isolated.
Kitti's hog-nosed bat roosts in the caves of limestone hills, far from the entrance. While many caves contain only 10 to 15 individuals, the average group size is 100, with a maximum of about 500. Individuals roost high on walls or roof domes, far apart from each other. Bats also undertake seasonal migration between caves.
Kitti's hog-nosed bat has a brief activity period, leaving its roost for only 30 minutes in the evening and 20 minutes at dawn. These short flights are easily interrupted by heavy rain or cold temperatures. During this period, the bat forages within fields of cassava and kapok or around the tops of bamboo clumps and teak trees, within one kilometre of the roosting site. The wings seem to be shaped for hovering flight, and the gut contents of specimens include spiders and insects that are presumably gleaned off foliage. Nevertheless, most prey is probably caught in flight. Main staples of the bat's diet include small flies (Chloropidae, Agromyzidae, and Anthomyiidae), hymenopterans, and psocopterans.
Late in the dry season (around April) of each year, females give birth to a single offspring. During feeding periods, the young either stays in the roost or remains attached to the mother at one of her two vestigial pubic nipples.
Kitti's hog-nosed bat is the only extant species in the family Craseonycteridae, which is grouped in the superfamily Rhinolophoidea as a result of molecular testing. Based on this determination, the bat's closest relatives are members of the families Hipposideridae and Rhinopomatidae.
Kitti's hog-nosed bat was unknown to the world at large prior to 1974. Its common name refers to its discoverer, Thai zoologist Kitti Thonglongya. Thonglongya worked with a British partner, John E. Hill, in classifying bats of Thailand; after Thonglongya died suddenly in February 1974, Hill formally described the species, giving it the binomial name Craseonycteris thonglongyai in honour of his colleague.
Soon after the bat's discovery in the 1970s, some roosting sites became disturbed as a result of tourism, scientific collection, and even the collection and sale of individuals as souvenirs. However, these pressures may not have had a significant effect on the species as a whole, since many small colonies exist in hard-to-access locations, and only a few major caves were disturbed. Another potential risk is the activity of local monks, who have occupied roost caves during periods of meditation.
Currently, the most significant and long-term threat to the Thai population could be the annual burning of forest areas, which is most prevalent during the bat's breeding season. In addition, the proposed construction of a pipeline from Burma to Thailand may have a negative impact. Threats to the Burmese population are not well known.
- Bates, P., Bumrungsri, S. & Francis, C. (2008). Craseonycteris thonglongyai. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 28 January 2009. Listed as Vulnerable
- "Bumblebee bat (Craseonycteris thonglongyai)". EDGE Species. Retrieved 2008-04-10.
- "Mammal record breakers: The smallest!". The Mammal Society. Archived from the original on July 13, 2007. Retrieved 2008-04-10.
- Hulva & Horáček (2002). "Craseonycteris thonglongyai (Chiroptera: Craseonycteridae) is a rhinolophoid: molecular evidence from cytochrome b". Acta Chiropterologica 4 (2): 107–120. doi:10.3161/001.004.0201.
- Goswami, A. 1999. Craseonycteris thonglongyai, Animal Diversity Web. Retrieved on 11 April 2008.
- Meyers, P. 1997. Bat Wings and Tails, Animal Diversity Web. Retrieved on 12 April 2008.
- MJR Pereira, Maria João Ramos et al. (October 2006). "Status of the world's smallest mammal, the bumble-bee bat Craseonycteris thonglongyai, in Myanmar". Oryx 40 (4): 456–463. doi:10.1017/S0030605306001268.
- Hutson, A. M., Mickleburgh, S. P. and Racey, P. A. (Compilers). 2001. Microchiropteran Bats: Global Status Survey and Conservation Action Plan. IUCN/SSC Chiroptera Specialist Group. IUCN: Gland, Switzerland.
- J. E. Hill and Susan E. Smith (1981-12-03). "Craseonycteris thonglongyai". Mammalian Species 160: 1–4. doi:10.2307/3503984.
- Schlitter, Duane A. (February 1975). "Kitti Thonglongya, 1928-1974". Journal of Mammalogy 56 (1): 279–280.
- "Protection for 'weirdest' species". BBC. 2007-01-16. Retrieved 2007-05-22.
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