Rhinolophus megaphyllussmaller horseshoe bat

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Geographic Range

Rhinolophus megaphyllus (smaller horseshoe bat or eastern horseshoe bat) is found in a large part of the Oriental biogeographic region and the eastern Australian region. Its distribution is throughout Thailand, Malaysia, Moluccas, New Guinea, the Lesser Sunda Islands, and the east coast of Australia. Accounts suggest that smaller horseshoe bats are found in the eastern portion of New Guinea. (Flannery, 1995; Grzimek, et al., 2003)

Habitat

Smaller horseshoe bats are found in temperate and tropical rainforests, deciduous forest, sclerophyll forest, woodlands, coastal scrub, and grasslands. They roost in caves, mines, rock outcrops, and non-occupied buildings. Smaller horseshoe bats can be seen forming colonies in abandoned bunkers. During the breeding season colonies are usually small, having less than twenty bats. However, outside of the breeding season, colonies consist of two thousand individuals. Those bats that occupy temperate regions become torpid during winter months and form single roosts. Tropical areas are occupied year round the bats remain active. ("Australian Museum Online", 2007; Grzimek, et al., 2003; Strahan, 1995)

Physical Description

Individuals have gray brown fur, with the abdominal fur being lighter than the rest. The lower portion of the nose is shaped like a horseshoe and there is a pointed nasal appendage on above the nose. There is a rufous form of smaller horseshoe bats that occurs in Queensland, Australia. These individuals tend to have more grey fur, as opposed to the standard brown. They are unique from the rest due to their fur, which changes color with age and sex. ("Australian Museum Online", 2007; Flannery, 1995; Grzimek, et al., 2003; Menkorst, 1995; Nowak, 1994; Strahan, 1995; Taylor, 1984)

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • Range mass
    7 to 10.5 g
    0.25 to 0.37 oz
  • Average mass
    7.5 g
    0.26 oz
  • Range length
    6.6 to 8.1 cm
    2.60 to 3.19 in
  • Average length
    7 cm
    2.76 in

Reproduction

One account of copulation places the incident during midday, in a cave; both individuals were hanging upside down by their toes. Smaller horseshoe bats are thought to be a polygynous species. (Grzimek, et al., 2003; Strahan, 1995)

Males produce sperm starting, approximately, in February and continuing through March. In the latter part of June copulation, ovulation, and fertilization occur. Gestation has a duration of approximately four months. Births occur from late October through November. The offspring are nursed for two months. During pregnancy females form maternity colonies that may have as few as fifteen individuals or as many as two thousand. This formation occurs during the spring and summer seasons, with choice roosting being in humid caves. The conditions of the cave are thought to increase the metabolic rate of individuals and ensure quick development of young. Maternity colonies created by females are distinct from winter roosts. There may only be a few males present, whereas the winter roosts are inhabited by males continuously. Males reach sexual maturity in the second to third year of life; females reach sexual maturity in their third year of life, sometimes the latter part of their second. (Grzimek, et al., 2003; Menkorst, 1995; Pavey, 1998; Strahan, 1995)

  • Breeding interval
    Smaller horseshoe bats give birth once yearly.
  • Breeding season
    Breeding occurs from February to March.
  • Average number of offspring
    1
  • Average gestation period
    4 months
  • Range weaning age
    6 (low) weeks
  • Average weaning age
    8 weeks
  • Range time to independence
    5 to 6.5 weeks
  • Average time to independence
    5 weeks
  • Range age at sexual or reproductive maturity (female)
    2 to 3 years
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Range age at sexual or reproductive maturity (male)
    2 to 2.5 years
  • Average age at sexual or reproductive maturity (male)
    2 years

Like other bat species, smaller horseshoe bat females care for their young until they can fly and find food on their own. Females invest heavily in young during gestation and lactation and young are adult sized within a few months of birth.

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

There is no information on the longevity of smaller horseshoe bats.

Behavior

Rhinolophus megaphyllus is thought to select roosts based on high humidity and relatively warm temperatures. Complete darkness does not appear to be a requirement. The high humidity of roost caves is thought to help keep bats from needing as much water, especially during times of inactivity. Roosts used for communal, year round living by the colony, are found in a variety of different locations. Caves are the top choice, however rock outcrops, abandoned buildings and bunkers are also used. Maternity colonies only occur in caves. (Grzimek, et al., 2003; Menkorst, 1995; Strahan, 1995)

Home Range

Home ranges are not documented for smaller horseshoe bats.

Communication and Perception

Members of Rhinolophus megaphyllus navigate and find food through the use of echolocation. They use constant frequency calls of 67 to 71 kHz. Individuals communicate through audible vocalizations and chemical cues. These bats also have keen vision. (Pavey and Burwell, 2005)

Food Habits

Smaller horseshoe bats are insectivores. They eat moths, other flying insects, and spiders. The prey they prefer are moths, specifically Speiredonia spectans and Speiredonia mutabilis. They obtain food primarily while flying. Their flight patterns are characterized by slow, fluttering flight around dense foliage. The echolocation calls of smaller horseshoe bats occur at frequencies that permit distinguishing between flying prey and the surrounding foliage. Smaller horseshoe bats stay primarily in wooded areas. They do not forage over grasslands. Individuals also capture prey by flying out from a stationary perch to catch passing prey. ("Australian Museum Online", 2007; Grzimek, et al., 2003; Pavey and Burwell, 2005; Pavey, 1998)

  • Animal Foods
  • insects
  • terrestrial non-insect arthropods

Predation

There are no specific reports of predation on smaller horseshoe bats. In general, bats are preyed on by owls and other raptors in flight and by arboreal predators in their cave roosts.

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Smaller horseshoe bats are important predators of insects in their native ecosystems.

Economic Importance for Humans: Positive

Smaller horseshoe bats are important member of native ecosystems. Their predation on flying insects can impact agricultural pest populations, providing a benefit to farmers.

  • Positive Impacts
  • controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of Rhinolophus megaphyllus on humans (Grzimek, et al., 2003)

Conservation Status

The status of Rhinolophus megaphyllus on IUCN Red List is lowest risk, least concern. This species was not listed under any appendices of CITES.

Other Comments

In most reference books these bats are referred to as eastern horseshoe bats.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Maya DiMeglio (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

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acoustic

uses sound to communicate

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

echolocation

The process by which an animal locates itself with respect to other animals and objects by emitting sound waves and sensing the pattern of the reflected sound waves.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

polygynous

having more than one female as a mate at one time

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

sperm-storing

mature spermatozoa are stored by females following copulation. Male sperm storage also occurs, as sperm are retained in the male epididymes (in mammals) for a period that can, in some cases, extend over several weeks or more, but here we use the term to refer only to sperm storage by females.

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

ultrasound

uses sound above the range of human hearing for either navigation or communication or both

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Australian Museum. 2007. "Australian Museum Online" (On-line). Bats in Australia. Accessed October 05, 2007 at http://www.austmus.gov.au/bats/records/bat15.htm.

Flannery, T. 1995. Mammals of New Guinea. New York: Cornell University Press.

Grzimek, B., N. Schlager, D. Olendorf. 2003. Eastern Horseshoe Bat. Pp. 387-396 in M McDade, ed. Grzimek's Animal Life Encyclopedia, Vol. Volume 13, Second Edition. Farmington Hills, MI: Thomson Gale Group.

Menkorst, P. 1995. Oxford Mammals of Victoria. Melbourne: Oxford University Press.

Nowak, R. 1994. Walker's Bats of the World. London: The John Hopkins University Press.

Pavey, C. 1998. Habitat use by the eastern horseshoe bat, Rhinolophus megaphyllus, in a fragmented woodland mosaic. Wildlife Research, 25/5: 489-498.

Pavey, C., C. Burwell. 2005. Cohabitation and predation by insectivourous bats on eared moths in subterranean roosts. Journal of Zoology, 265: 141-146.

Strahan, R. 1995. Mammals of Australia. Washington D.C.: Smithsonian Institution Press.

Taylor, J. 1984. Oxford Guide to Mammals of Australia. Melbourne: Oxford University Press.