Hardwicke's Woolly Bat (Kerivoula hardwickii)


Range Description:

This widespread species ranges from Southern and Northern South Asia, Southern China, and throughout continental and insular Southeast Asia. In South Asia, this species is presently known from Bangladesh (no exact location) (Das, 2003, Srinivasulu and Srinivasulu, 2005), India (Assam, Jammu and Kashmir, Karnataka, Meghalaya, Mizoram, Nagaland and West Bengal), Pakistan (Punjab) and Sri Lanka (Central Province) (Srinivasulu et al. in press). In China, it is widely distributed in the Southeast of the country, including the island of Hainan. In Southeast Asia, it is found throughout the mainland, in insular Southeast Asia it ranges from Indonesia (the Mentawi Islands [Siberut and Sipura], Sumatra, Java, Bali, Kangean, Nusa Penida, Lombok, Sumba, Sulawesi, Pelang, Banggi, Karakelang), to the island of Borneo (Brunei, Indonesia and Malaysia) to the Philippines, where it has been recorded from the islands of Biliran, Leyte, Luzon (Camarines Sur Province), Mindanao (Bukidnon Province), Palawan, and Samar (Taylor 1934; Heaney et al. 1998). Over its range, it has been recorded between 60 and 2,100 m asl.
Countries: Native:
Brunei Darussalam; Cambodia; China; Indonesia (Jawa, Kalimantan, Lesser Sunda Is., Sulawesi, Sumatera); Lao People's Democratic Republic; Malaysia (Sabah, Sarawak); Myanmar; Philippines; Thailand; Vietnam


HB: 44-54; T;36-48; FA: 31-34; E:11-12; HF:7-10

Woolly Bats are small insectivorous bats which inhabit primary and secondary forest. The ears are somewhat rounded and barely extend above the top of the fur on top of the domed skull. The distinctive tragus is narrow, pointed and projects upwards inside the ear (see lower photo) The orange-brown fur is thick, long and fluffy and covers much of the face. The eyes are tiny and the mouth small. The tail is fully enclosed in the flight membrane.

Morphological Description

·A very small bat: dorsally the fur is smoky brown, the ventral surface is greyish-ochre.

·The size difference between the first two upper premolars P2 and P3, and the last upper premolar P4 is more conspicuous than in Kerivoula picta (Smith & Xie 2008).

· Forearm length 31-36 mm, ear length 11-15 mm (Smith & Xie 2008).


In Southeast Asia it is a moderately common species in primary forest (L. Heaney pers. comm.). The abundance, population size and trends for this species in South Asia are not known (Molur et al. 2002).
Population Trend: Stable

Habitat and Ecology:

In South Asia, little is known about the habitat or ecology of this species except that it is found in warm valleys in Northeast India and near paddy fields in Sri Lanka and known to roost in caves and buildings in forests (Molur et al. 2002). In China, it is found in subtropical and tropical areas, and has been collected in both forested and agricultural localities. Animals sometimes forage around houses and villages, and roost in buildings and under tile roofs on occasion (Smith and Xie 2008). In Southeast Asia, there are records from primary forest in Cambodia (G. Csorba pers. comm. 2006), dry forest including disturbed sites in Lao PDR, and hill forest in Peninsular Malaysia (Francis pers. comm. 2006). On Banggi Island (Indonesia) the species was found roosting in the axial of a rattan vine leaf. In the Philippines, it has been recorded in lowland, montane, and ridge top mossy forest (Rickart et al. 1993). On Palawan Island, there are records from a bamboo thicket at 60 m and primary lowland forest at 650 m (Esselstyn et al. 2004). Hardwicke's Woolly Bat (Kerivoula hardwickii) lives in the forest under storey (Francis 2008). where roosts have been found in hollow trees and among clusters of dead leaves (Francis 2008).   It is low flying, and very manoeuvrable.  The echolocation calls are likely to be frequency modulated, brief and to cover a wide range of frequencies if they are similar to other Kerivoula species described by Kingston et al. (1999).
Systems: Terrestrial

Additional Information

Tiny Borneo bats roost in carnivorous pitcher plants

 Tiny bats, no bigger than a car key, have been discovered roosting in carnivorous pitcher plants in Borneo -- with their droppings a vital nutrient for the plants.

"It's totally unexpected," said Ulmar Grafe, an associate professor at the University Brunei Darussalam who led the study.

"There's a lot of animal-plant mutualisms, but this one is where the animal gives a nutrient to a plant. Usually it's the other way around."

The study, published in Biology Letters, began by looking at how the pitcher plant -- a vine growing up to 6-10 meters (20 ft to 33 ft) long with 25 cm (10 inch) pitchers -- managed to gain the nitrogen it needed in the nutrient-poor peat swamps and heath forest on the island of Borneo.

Grafe's team was surprised to find that the roughly 4 gram (0.14 oz) Hardwicke's woolly bat (Kerivoula hardwickii) consistently chose the pitchers to sleep in during the day, despite a wealth of other possible roosts in the nearby forest.

Not only single bats but male and female pairs, and mother-juvenile pairs, can fit inside comfortably. At night, they fly out to hunt insects.

"The pitcher is a very nice roost for them," Grafe said. "It's dry in there and there's no build-up of blood-sucking ectoparasites that often accumulate in other cavities."

Theoretically, there is some danger to the bat should it fall into the digestive fluid at the bottom of the pitcher. But the plant has adaptations to prevent this, including an unusually low amount of fluid and a tapering pitcher.

Instead of getting nitrogen by consuming the bats, the plants get it from their feces.

"There's no reason why the bat couldn't fly outside. But they probably defecate in there because they usually do that when they roost," Grafe said.

The find is an example of why diversity matters, he added, noting that much of the forest in Borneo is under threat.

"There's so much extinction of animals and reduction of populations and removal that this again highlights how important it is to save every individual, every creature out there."

Major Threat(s):

There appear to be no major threats to this somewhat adaptable species.

Conservation Actions:

 In South Asia, although there are no direct conservation measures in place, the species has been recorded from protected areas in India like Siju Wildlife Sanctuary in Meghalaya. It has been recorded from protected areas in parts of Southeast Asia. Further studies are needed into the taxonomy of this species.