Vespertilionid bats II

(Other subfamilies)

Class Mammalia

Order Chiroptera

Suborder Microchiroptera

Family Vespertilionidae

Thumbnail description
Small- to medium-sized bats, frequently brown in color, but occasionally with strikingly colored fur

Size
Range about 1.2–3.0 in (3.1–7.5 cm) in body length, and about 0.07–0.7 oz (2–20 g) in weight

Number of genera, species
5 genera; at least 48 species

Habitat
Forested areas, frequently near rocky outcrops and caves

Conservation status
Critically Endangered: 1 species; Endangered: 3 species; Vulnerable: 6 species; Lower Risk: 14 species

Distribution
Southern Europe, southern and eastern Africa, southern Asia, Indonesia, New Guinea, Australia, and Peru

Evolution and systematics

The family Vespertilionidae is commonly split into five subfamilies, including the enormous Vespertilioninae, which is treated in a separate chapter. The remaining four subfamilies are:

• Miniopterinae
• Murininae
• Tomopeatinae
• Kerivoulinae

The subfamily Kerivoulinae is the largest with one genus (Kerivoula) and 22 species, followed by the subfamily Murininae with two genera (Harpiocephalus and Murina) and 15 species. The subfamily Miniopterinae has one genus (Miniopterus) and 10 species, and the subfamily Tomopeatinae includes a single species, Tomopeas ravus. Although the subfamilies are relatively small, taxonomists are still struggling with their taxonomy. For example, some scientists consider the murinines a separate family, or split the Kerivoula genus and place some of the species in a separate Phoniscus genus. In addition, controversy exists over whether to place T. ravus in the family Molossidae or Vespertilionidae. Based on its morphology, which includes features of both the vespertilionids and molossids, many believe T. ravus may represent an ancestor to both families.

Physical characteristics

Since all four subfamilies are in the family Vespertilionidae, they share some features, including a well-developed tragus that reaches up from the base of the ear, a nearly naked patagium, or flight membrane, that covers a relatively long tail, and

the lack of the fleshy nose ornament common to so many other bat families. Unlike other vespertilionids, however, species in the subfamily Murininae have nostrils appearing at the end of tube-shaped nose. Tomopeas lacks the anterior basal earlobe present in the other subfamilies. Miniopterines have an extremely long third finger that they can fold, earning them the moniker bent-wing bats. Members of the subfamily Kerivoulinae all share a long, slender, pointed tragus.

Distribution

The species of the subfamily Kerivoulinae extend through central and southern Africa, and from India east to China, throughout southeast Asia, Indonesia, New Guinea and northeastern Australia. The subfamily Miniopterinae reaches into central and southern Africa, as well as Madagascar, and from southern Europe and Asia north into China, and also New Guinea, Indonesia, and Australia. Murinines are only

slightly less widespread, reaching from southern Asia north into China, and through Indonesia, New Guinea, and northeast Australia. Tomopeas is found strictly in western Peru.

Habitat

Species in these four subfamilies range in their habitat choices from subtropical to temperate forests and fields, frequently selecting areas that are near caves or rocky outcrops commonly used for roosts. Members of the Miniopterus species, for example, use caves for both summer and winter roosts. Some Murina species, on the other hand, can roost among the leaves of trees and vines, and do not require underground sites. Some Kerivoula species also use bird nests for roosting sites.

Behavior

The more temperate bats in these four subfamilies, including many Miniopterus species, migrate 100 mi (160 km) or more in the winter and spend much of the season in hibernation, while those that live in more tropical climates may stay in one general area and remain active throughout the year. In the spring, when young are typically born, females of most species form maternity colonies. Males usually do not roost within these large groups. Overall, little is known about the behavior of most of these bats.

Feeding ecology and diet

These bats are nocturnal, typically becoming active shortly after sunset and feeding on various insects well into the night. Recent studies reveal that the diet of Kerivoula papuensis may primarily be spiders rather than insects. Analyses of fecal matter indicate that more than 90% of its diet consists of arachnids.

Reproductive biology

Little is known about the reproductive biology of many of these species. It is assumed, however, that at least the temperate species mate in the fall. Most vespertilionids in the temperate regions have delayed fertilization, with sperm being stored in the winter within the female reproductive tract. Females then ovulate and fertilization occurs in the spring. With Miniopterinae, following delayed implantation of the embryo until late winter or early spring, females give birth to litters averaging one or two pups in the late spring or early summer. The capture of gravid warmer-climate females suggests that these species are capable of producing offspring all year long.

Conservation status

Fully half of the species in these four subfamilies are listed as Lower Risk, Vulnerable, Endangered, or Critically Endangered by the IUCN. The population declines are often accompanied by reports of habitat destruction. The golden-tipped bat (Kerivoula papuensis) is an example of a bat that may be facing a threat from habitat loss. A major challenge to scientists now is to learn more about this and other species that have historically been difficult to find. In fact, the golden-tipped bat was considered extirpated from Australia until it was rediscovered in 1981. With new trapping and monitoring techniques, scientists are beginning to gather data about habitat and feeding requirements. This information is critical in developing effective conservation plans.

Significance to humans

Like most bats, the species within these four subfamilies are insectivorous, making them beneficial in controlling various beetles and other agricultural pest populations.

Species accounts

List of Species

Harpy-headed bat

Harpiocephalus harpia

subfamily

Murininae

taxonomy

Harpiocephalus harpia (Temminck, 1840), Mt. Gede, Java, Indonesia. Two subspecies.

other common names

English: Harpy-winged bat, hairy-winged bat.

physical characteristics

Average adult body length is 2.2–3.0 in (5.5–7.5 cm), and fore-arm length is 1.6–2.1 in (4.0–5.4 cm). Reddish orange, furry bat, somewhat mottled with gray, and a lighter underside. It has a tube-shaped nose.

distribution

India through Southeast Asia and Indonesia.

habitat

Hilly areas and lowland forest.

behavior

Little known, but are believed to roost in foliage.

feeding ecology and diet

Little known, but have been reported to eat beetles.

reproductive biology

Nothing is known.

conservation status

Not threatened.

significance to humans

May help control populations of crop-damaging insects.

Brown tube-nosed bat

Murina suilla

subfamily

Murininae

taxonomy

Murina suilla (Temminck, 1840), Java, Indonesia.

other common names

English: Brown murine bat.

physical characteristics

Average adult body length is 1.3–2.4 in (3.3–6.0 cm), weight is 0.11–0.18 oz (3–5 g), and forearm length is 1.0–1.8 in (2.6–4.5 cm). Dark grayish brown, furry bat with a tube-shaped nose. Its underside is whitish, and it has brown wing membranes.

distribution

Western Malaysia and Indonesia, including Borneo.

habitat

Hilly areas, often near cultivated and grassy fields.

behavior

Forage flights take them close to the ground, often barely over the tops of fields. Often roost together in foliage.

feeding ecology and diet

Insectivorous.

reproductive biology

Nothing is known.

conservation status

Not threatened.

significance to humans

May help control insects that damage crops.

Common bentwing bat

Miniopterus schreibersi

subfamily

Miniopterinae

taxonomy

Miniopterus schreibersi (Kuhl, 1817), Banat, Romania. Two sub-species.

other common names

English: Schreiber's long-fingered bat, Schreiber's bent-winged bat, greater bent-winged bat, long-winged bat; French: Minoptère à longues ailes; German: Langflügelfledermaus; Spanish: Murcielago de cueva.

physical characteristics

Average adult body length is 2.0–3.1 in (5.1–7.8 cm), weight is 0.28–0.56 oz (8–16 g), and forearm length is 1.7–2.0 in (4.2–5.0 cm). Gray to golden or reddish brown, thickly furred bat with a long tail; long, slender wings; and short ears.

distribution

Along the Mediterranean Sea in Europe and Africa, Africa south of the Sahara, southern Asia, New Guinea, and northern and eastern Australia.

habitat

Found in forests in the vicinity of caves or other rocky areas, usually near a subterranean water source, in summer and winter.

behavior

Tens of thousands of common bentwing bats may roost together in the winter, and northernmost populations may hibernate. After migrating up to 200 mi (322 km) north in the spring, the males disperse, but females and their young continue to roost together in maternity colonies of many thousand bats. The body heat of so many bats helps to maintain a tolerable temperature in the cool summer caves. Sometimes, individuals or small groups may roost in a nearby secondary roost. Shortly after sunset, the bats emerge from their roosts to forage throughout the night.

feeding ecology and diet

The diet of these speedy, nocturnal bats includes small insects, especially beetles.

reproductive biology

Most likely polygynous. Mating commonly occurs in the fall, with delayed implantation until winter. Gestation lasts about 115–130 days after implantation. The young are born in early summer. In more tropical populations, implantation may occur almost immediately with young born up to four months earlier than in temperate areas. Litter size is typically one young per female. The young are weaned at about two months. They attain sexual maturity at 1 year old.

conservation status

Listed as Lower Risk/Near Threatened by the IUCN. Population declines, including the disappearance of entire colonies, have been reported in western Europe.

significance to humans

Eat beetles and other insects that are potentially damaging to agricultural crops.

Painted bat

Kerivoula picta

subfamily

Kerivoulinae

taxonomy

Kerivoula picta (Pallas, 1767), Ternate Island, Molucca Islands, Indonesia.

other common names

None known.

physical characteristics

Average adult body length is 1.6–1.7 in (4.0–4.3 cm), forearm length is 1.3–1.5 in (3.4–3.9 cm), and weight about 0.21–0.28 oz (6–8 g). A vivid orange to reddish, furry bat with black wings set off by orange fingers.

distribution

From India to southern China, south to Indonesia.

habitat

Forests, often roosting in tall grass or among foliage.

behavior

These bats will roost in nearly any cavity, including the spaces between leaves and flowers, and in bird nests. They often roost alone or in small groups of up to a half dozen bats. Nocturnal, they become active after dark, and forage above low vegetation.

feeding ecology and diet

Insectivorous.

reproductive biology

Nothing is known.

conservation status

Not threatened.

significance to humans

May help control insects that damage crops.

Resources

Books

Altringham, J. Bats: Biology and Behavior. Oxford: Oxford University Press, 1996.

Fenton, M. Bats. New York: Checkmark Books, 2001.

Medway, L. The Wild Mammals of Malaya (Peninsular Malaysia) and Singapore. 2nd ed. Oxford: Oxford University Press, 1978.

Nowak, R. Walker's Mammals of the World. Baltimore: Johns Hopkins University Press, 1999.

Periodicals

Bernard, R., F. Cotterill, and R. Fergusson. "On the occurrence of a short period of delayed implantation in Schreiber's long-fingered bat (Miniopterus schreibersii) from a tropical latitude in Zimbabwe." Journal of Zoology: Proceedings of the Zoological Society of London 238, no. 1 (1996): 13.

Hannah, D., and M. Schulz. "Relative abundance, diet and roost selection of the tube-nosed insect bat, Murina florium, on the Atherton Tablelands, Australia." Wildlife Research 25, no. 3 (1998): 261.

Schulz, M. "Diet and foraging behavior of the golden-tipped bat, Kerivoula papuensis: A spider specialist?" Journal of Mammalogy 81, no. 4 (2000): 948–957.

Organizations

Bat Conservation International. P.O. Box 162603, Austin, TX 78716 USA. Phone: (512) 327-9721. Fax: (512) 327-9724. E-mail: [email protected] Web site: <http://www.batcon.org>

The Bat Conservation Trust. 15 Cloisters House, 8 Battersea Park Rd., London, SW8 4BG UK. Phone: 020 7627 2629. Fax: 020 7627 2628. E-mail: [email protected] Web site: <http://www.bats.org.uk/aboutbct.htm>

The Organization for Bat Conservation at Cranbrook Institute of Science. 39221 Woodward Avenue, P.O. Box 801, Bloomfield Hills, MI 48303-0801 USA. Phone: (800) 276-7074. E-mail: [email protected] Web site: <http://batconservation.org/>

Leslie Ann Mertz, PhD