Kitti's hog-nosed bat (''Craseonycteris thonglongyai''), also known as the bumblebee bat, is a

near-threatened species A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to endangerment in the near future, but it does not currently qu ...

bat Bats are flying mammals of the order Chiroptera (). With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more agile in flight than most birds, flying with their very long spread-out ...

and the only extant member of the family Craseonycteridae. It occurs in western

Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...

and southeast

Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...

, where it occupies

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

caves along rivers. Kitti's hog-nosed bat is the smallest species of bat and arguably the world's smallest mammal by body length (the

Etruscan shrew The Etruscan shrew (''Suncus etruscus''), also known as the Etruscan pygmy shrew, white-toothed pygmy shrew and Savi's pygmy shrew, is the smallest known extant mammal by mass, weighing only about on average. (The bumblebee bat is regarded as t ...

is regarded as the smallest by body mass). 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 Myanmar is not well known, the Thai population is restricted to a single province and may be at risk of

extinction Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

. Its potential threats are primarily

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Anthropogenic may also refer to things that have been generated by humans, as follows: * Human impact on the enviro ...

, and include

habitat degradation Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

and the disturbance of

roosting Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight ...

sites.

Description

Kitti's hog-nosed bat is small at about in length and in mass, hence the common name of "

bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only Extant taxon, extant group in the tribe Bombini, though a few extinct r ...

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

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

s; in particular, the

may be lighter at but its body is longer, measuring 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.Goswami, A. 1999.
''Craseonycteris thonglongyai''
Animal Diversity Web. Retrieved on 11 April 2008. In the jaw, the premaxillae are not fused with surrounding bones, and the coronoid process is significantly reduced. Its teeth are typical of an

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores we ...

bat. The

dental formula Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...

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. The second digit of the wing is made of a single short phalanx. And the humerus has an increased number of locking tubercles on its head and beyond. There is a considerable fusion in the axial skeleton, concerning the thoracic (three posterior vertebrae), lumbar (two posterior) and sacral (all) sections. The bat has particularly slender legs, with rather thin

fibula The fibula (: fibulae or fibulas) or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. ...

. Despite having two caudal

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

e, Kitti's hog-nosed bat has no visible tail. There is a large web of skin between the hind legs (the

uropatagium The patagium (: patagia) is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, theropod dinosaurs (including b ...

) which may assist in flying and catching insects, although there are no tail bones or

calcar The calcar, also known as the calcaneum, is the name given to a spur of cartilage arising from inner side of ankle and running along part of outer interfemoral membrane in bats, as well as to a similar spur on the legs of some arthropods. The cal ...

s to help control it in flight.

Range, habitat and diversity

Kitti's hog-nosed bat occupies limestone caves along rivers within dry

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

forests. In Thailand, it is restricted to a small region of the

Tenasserim Hills The Tenasserim Hills or Tenasserim Range (, ; , , ; ) is the geographical name of a roughly 1,700 km long mountain chain, part of the Indo-Malayan mountain system in Southeast Asia. Despite their relatively scant altitude these mo ...

in Sai Yok District,

Kanchanaburi Province Kanchanaburi (, ) is the largest of the western Provinces of Thailand, provinces (''changwat'') of Thailand. The neighboring provinces are (clockwise, from the north) Tak province, Tak, Uthai Thani province, Uthai Thani, Suphan Buri province, Sup ...

, within the

drainage basin A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, ...

of the

Khwae Noi River The River Kwai (), more correctly Khwae Noi (, , 'small tributary') or Khwae Sai Yok (, ), is a river in western Thailand. It rises to the east of the Salween in the north–south spine of the Bilauktaung range near, but not over the border wi ...

. While

Sai Yok National Park Sai Yok National Park () is a List of national parks of Thailand, national park in Sai Yok District, Sai Yok district, Kanchanaburi Province, Thailand, near the town Nam Tok Sai Yok Noi. The park, home to mountains, waterfalls and caves, is part o ...

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 Myanmar, at least nine separate sites have been identified in the limestone outcrops of the Dawna and

Karen Hills The Karen Hills, (, Burmese language, Burmese: ကရင်တောင်တန်း) also known as Kayah-Karen Mountains, are one of the main hill ranges in eastern Burma. They are located at the SW corner of Shan State and in Kayah State, a ...

outside the Thanlwin, Ataran, and Gyaing Rivers of Kayin and

Mon State Mon State (, ; ) is an administrative division of Myanmar. It lies between Kayin State to the east, the Andaman Sea to the west, Bago Region to the north and Tanintharyi Region to the south, also having a short border with Thailand's Kanchanabu ...

s. The Thai and Myanmar populations are morphologically identical, but their echolocation calls are distinct. It is not known whether the two populations are reproductively isolated. Despite its restricted geographical range and specialized habitat requirements, Kitti's hog-nosed bat exhibits remarkable genetic diversity within its populations. Molecular analyses using microsatellite markers have revealed moderate levels of genetic differentiation among cave roosts in Thailand and Myanmar, suggesting historical isolation and limited gene flow between populations.

Biology and reproductive structure

Kitti's hog-nosed bat roosts in caves in 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 ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...

and kapok or around the tops of

bamboo Bamboos are a diverse group of mostly evergreen perennial plant, perennial flowering plants making up the subfamily (biology), subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in th ...

clumps and

teak Teak (''Tectona grandis'') is a tropical hardwood tree species in the family Lamiaceae. It is a large, deciduous tree that occurs in mixed hardwood forests. ''Tectona grandis'' has small, fragrant white flowers arranged in dense clusters (panic ...

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 Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

( Chloropidae, Agromyzidae, and

Anthomyiidae The Anthomyiidae are a large and diverse family (biology), family of Muscoidea fly, flies. Most look rather like small houseflies. Most species are drab grey to black. Many ''Pegomya'' are yellow, and some members of the genus, genera ''Ant ...

hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

ns, and

psocoptera Psocoptera () are a paraphyletic group of insects that are commonly known as booklice, barklice or barkflies. The name Psocoptera has been replaced with Psocodea in recent literature, with the inclusion of the former order Phthiraptera into Psoc ...

ns. Kitti's hog-nosed bat suggest a unique reproductive strategy characteristic of microchiropterans. Females of this species typically give birth to a single offspring per reproductive event, with births occurring during the dry season between March and May. Maternity colonies composed of a small number of females are formed within cave roosts, providing communal protection and thermoregulatory benefits for nursing offspring. Male mating behaviors, such as courtship vocalizations and scent marking, have been documented in captive populations, indicating potential sexual selection mechanisms.

Taxonomy

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 The Hipposideridae are a family (biology), family of bats commonly known as the Old World leaf-nosed bats. While it has often been seen as a subfamily, Hipposiderinae, of the family Rhinolophidae, it is now more generally classified as its own fa ...

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.

Ecological role and conservation

As a microchiropteran species, Kitti's hog-nosed bat plays a crucial ecological role in its habitat, primarily as an insectivore. This species preys predominantly on small flying insects, including mosquitoes, moths, and beetles. By controlling insect populations, particularly those of agricultural pests and disease vectors, Kitti's hog-nosed bat contributes to ecosystem balance and human well-being. Furthermore, its presence in cave ecosystems may also influence nutrient cycling and the distribution of guano-dependent organisms. As of the species' review in 2019, Kitti's hog-nosed bat is listed by the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

near-threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to endangerment in the near future, but it does not currently qu ...

, with a downward population trend. 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 gas pipeline from Myanmar to Thailand may have a negative impact. Threats to the Myanmar population are not well known. In 2007, Kitti's hog-nosed bat was identified by the Evolutionarily Distinct and Globally Endangered project as one of its Top 10 "focal species".

References

External links

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Information and image at ADW
{{Good article Bats by classification

Kitti's Hog-nosed Bat Kitti's hog-nosed bat (''Craseonycteris thonglongyai''), also known as the bumblebee bat, is a near-threatened species of bat and the only extant member of the family Craseonycteridae. It occurs in western Thailand and southeast Myanmar, where it ...

Mammals of Myanmar Mammals of Thailand EDGE species