• Known from western Thailand and south-east Myanmar.
  • Roughly the size of a large bumblebee, this tiny bat is possibly the world’s smallest mammal.
  • This species constitutes the sole known representative of an entire family of bats (Craseonycteridae). It is thought to have last shared a common ancestor with other species around 43 million years ago.
  • Found in the middle and lower reaches of the Yangtze River, China.
  • Although the species may be locally common it has a very restricted distribution and is therefore vulnerable to a range of threats.
  • Some populations declined following tourist disturbance of certain roost sites throughout the 1970s, collection for scientific purposes and the sale of bats as tourist souvenirs.
  • Today, the main threat to the Thai population comes from the annual burning of forest areas near the caves.
  • The main threats to the Myanmar population are currently unknown.
Conservation Required
  • Prohibit all trade and non-essential scientific collection and develop a management policy for habitats used as flight paths and foraging areas.
  • Minimise cave disturbances and protect key roost sits with fences or grilles if necessary.
  • Provide information on the importance of protecting the species to visitors of Sai Yok National Park, Thailand.
  • Conduct further research on the status, distribution and habitat requirements of the species in Thailand and Myanmar.
  • Develop a monitoring programme to identify population change in relation to environmental factors.

Proposed Actions

EDGE aims to monitor the bumblebee bat in Sai Yok National Park and adjacent areas in western Thailand to inform future management programmes for this species.

The world's smallest mammal, the bumblebee bat is known only from western Thailand and, more recently, south-east Myanmar. Since it was first described in 1974 the Thai population has been disturbed by collectors and tourists wanting to see the world's smallest mammal. Today the main threats are from burning of the forest areas near the limestone caves in which it lives.

EDGE is supporting a Thai PhD student to carry out research on roost selection behaviour and threats to bumblebee bats in Sai Yak National Park, Thailand. The results of this study will help to inform a management strategy for the species.

We are also hoping to work with local and international bat experts to implement a bat monitoring programme in Thailand, focusing on the bumblebee bat. Like other small bats, this species uses ultrasound to navigate and forage for food. Researchers can use bat detectors to pick up the call of bats in their roosts and hibernation sites, and use the information collected to monitor populations.

More Focal Mammal species

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Associated Blog Posts
13th Jun 10
The smallest mammal in the world is EDGE Mammal number 49 and is today's Species of the Day. This tiny bat weighs less than 2 grams. Its body is about the si...  Read

6th Apr 08
Researchers from the Institute of Zoology;  Dr Kate Jones and Alanna Maltby have just returned back from a recent trip to Thailand where they were par...  Read

12th Mar 08
Piyathip Piyapan our Thai EDGE Fellow currently studying the roost selection of Bumblebee bats  (otherwise known as Kitti's hog-nosed bat) sent the EDGE Te...  Read