Kitti’s hog-nosed bat (Craseonycteris thonglongyai)

Also known as: bumblebee bat, hog-nosed bat, Old World hog-nosed bat
GenusCraseonycteris (1)
SizeHead-body length: 29 – 33 mm (2)
Weight1.7 – 2.0 g (2)

Kitti's hog-nosed bat is classified as Vulnerable (VU) on the IUCN Red List (1).

Kitti's hog-nosed bat (Craseonycteris thonglongyai) is not only the smallest bat in the world, but also the smallest mammal in existence, and the sole living species of the family Craseonycteridae (2) (3). Its extinction would not only be the loss of an incredibly unique species, but an entire branch of the evolutionary tree would vanish from our planet. Kitti’s hog-nosed bat has long greyish-brown fur on its back, and shorter, paler fur on its underparts (2). Its common name arises from its flat, fleshy, pig-like muzzle (2), situated between extremely small eyes concealed by facial hair (2). Their large and membranous ears, with a long and well-developed tragus, enhance their ability to pinpoint the echoes with which they navigate (2) (3). Male Kitti’s hog-nosed bats possess a rounded, glandular swelling on the lower portion of the throat; this is either less prominent or completely absent in females (2).

Kitti’s hog-nosed bat has been found in the Kanchanaburi Province of west-central Thailand (2), and in Mon State, south-east Myanmar (4) (5).

Kitti’s hog-nosed bat inhabits limestone caves situated amongst bamboo forests and deciduous hardwood trees (2) (6).

This apparently wary bat can be found deep inside small caves, hanging high on the ceiling, suspended by their toes and strong claws (2). A ‘tendon-locking mechanism’ keeps their claws bent with very little muscular effort, and hanging upside down allows the bat to swiftly take flight from the resting position (3). Many caves in which Kitti’s hog-nosed bats have been found contain only 10 to 15 individuals, but the average group size is 100, and the maximum is 500 (6). Females give birth to a single young in late April, the dry season, and leave their offspring in the roost whilst they venture out to forage (6).

Kitti’s hog-nosed bats emerge from their caves shortly after sunset, and again just before dawn, when they hunt for brief periods (2) (3). They search for prey around the tops of teak trees and bamboo clumps (6), gleaning insects from foliage and seizing small flying insects from the air (2). Like other bats, the Kitti’s hog-nosed bat can locate prey and navigate through the trees by using echolocation. They emit ultrasonic squeaks that bounce off their surroundings, and the echoes are used to create a mental map of the area, and determine the location of potential prey (3).

Shortly after the discovery of this unique species in the 1970s, the Kitti’s hog-nosed bat came under threat from disturbance by tourists, scientific collection, and collection for tourist souvenirs (6). Such disturbance has led to some caves being abandoned in Thailand (4), but luckily, the inaccessibility of many of their roost caves has prevented the whole population being affected (6). Today, different threats prevail. In Myanmar, Kitti’s hog-nosed bat may be impacted by the smoke and dust emitted from cement factories located close to where the bats forage (4). Many of the caves are Buddhist sites that attract a growing number of pilgrims for meditation. Unfortunately this quiet activity still involves sufficient disturbance and may provoke the bat to abandon its roost (4) (6), although the presence of monks also has the benefit of restricting hunting of the bats (4). Another serious threat arises from the burning of forest near the bat caves, which destroys critical foraging habitat (6). There is also a proposal to construct a pipeline from Myanmar to Thailand (6), which could potentially greatly impact this species through disturbance and habitat degradation.

Kitti’s hog-nosed bats occur within Sai Yok National Park (1), which offers some protection. A Conservation Action Plan was created for this species in 2001, which recommends actions for the conservation of the species (6). These recommendations include monitoring, providing incentives to local people to maintain essential habitat, and identifying and protecting key cave roosts (6).

For more information on Kitti’s hog-nosed bat and its conservation: 

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. IUCN Red List (June, 2009)
  2. Hill, J.E. and Smith, S.E. (1981) Craseonycteris thonglongyai. Mammalian Species, 160: 1 - 4.
  3. Jones, G. (2006) Bats. In: Macdonald, D.W. (Ed) The Encyclopedia of Mammals. Oxford University Press, Oxford.
  4. Pereira, M.J.R., Rebelo, H., Teeling, E.C., O’Brien, S.J., Mackie, I., Bu, S.S.H., Swe, K.M., Mie, K.M. and Bates, P.J.J. (2006) Status of the world’s smallest mammal, the bumble-bee bat Craseonycteris thonglongyai, in Myanmar. Oryx, 40(4): 456 - 463.
  5. Bates, P.J.J., Nwe, T., Swe, K.M. and Bu, S.S.H. (2001) Further new records of bats from Myanmar (Burma), including Craseonycteris thonglongyai Hill 1974 (Chiroptera: Craseonycteridae). Acta Chiropterologica, 3: 33 - 41.
  6. Hutson, A.M., Mickleburgh, S.P. and Racey, P.A. (2001) Microchiropteran bats: global status survey and conservation action plan. IUCN, Gland, Switzerland and Cambridge, UK.