Pteropus melanotusblack-eared flying fox

Geographic Range

The type locality of black-eared flying foxes is the Nicobar Islands in India. They are found throughout many islands in Southeast Asia, including the Andaman Islands in India, the Engano and Nias Islands in Indonesia, and Christmas Island, south of Java. (Wilson, 1993)

Habitat

Pteropus melanotus is generally found in forests and swamps on small, oceanic islands. They roost in rainforest trees on these islands. ("Australian Museum Online", 1999; Tidemann R, 1994; "Australian Museum Online", 1999; Tidemann R, 1994)

  • Average elevation
    0 m
    0.00 ft

Physical Description

Black-eared flying foxes have dark brown to black fur, except in the chest and neck region where the fur is light brown. The genus Pteropus includes the largest bat species in the world. No records of body measurements could be found in the literature. Males of Pteropus species tend to be larger than females and species range in size from 170 to 406 mm in body length and 610 to 1,700 mm wingspan. (McNab and Armstrong, 2001; "University of Michigan Museum of Zoology: Animal Diversity Web", 2002; Nowak, Ronald M, 1999)

  • Sexual Dimorphism
  • male larger

Reproduction

There is no information on the mating systems of black-eared flying foxes. In many species of Pteropus males form mating harems during temporary breeding aggregations. (Nowak, Ronald M, 1999)

Little is known about the reproductive behavior of Pteropus melanotus except that breeding occurs once a year, and February tends to be the peak birthing time. Pteropus melanotus individuals reach sexual maturity in only six months, less than any other flying fox species which generally reach sexual maturity in 18 to 24 months. ("Christmas Island", 2006; Nowak, Ronald M, 1999)

  • Breeding interval
    Breeding occurs once yearly.
  • Breeding season
    Births peak in February.
  • Average number of offspring
    1
  • Average age at sexual or reproductive maturity (female)
    6 months
  • Average age at sexual or reproductive maturity (male)
    6 months

Black-eared flying fox females nurse and care for their young until they reach independence. In most Pteropus species, females carry their young for the first few weeks after birth. Subsequently they leave the young in a roost while foraging, returning to nurse them. Pteropus species young generally become independent 2 to 3 months after birth. (Nowak, Ronald M, 1999)

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

Lifespan/Longevity

Other Pteropus species have record life spans around 25 to 35 years, but there is no specific information on P. melanotus. ("Aging Cell", 2002; Nowak, Ronald M, 1999)

Behavior

Black-eared flying foxes are one of the few species of bats that are active during the day. They tend to roost in groups of several hundred bats, and during the day can be seen flying in large groups in updrafts near cliff faces. ("Australian Museum Online", 1999; "Christmas Island", 2006; Nowak, Ronald M, 1999)

Home Range

Home ranges of black-eared flying foxes are unknown.

Communication and Perception

Black-eared flying foxes use their keen vision in low light to navigate. They also use olfaction to find fruits and communicate reproductive status. (Nowak, Ronald M, 1999)

Food Habits

Black-eared flying fox diet consists mainly of fruits and blossoms of rainforest trees. They tend to favor Muntingia calabura, which is an introduced Japanese cherry. ("Australian Museum Online", 1999; "Christmas Island", 2006)

  • Plant Foods
  • fruit
  • flowers

Predation

Domestic cats (Felis silvestris) are the main predators of Pteropus melanotus on Christmas Island, making up 21 percent of their diet by weight. Humans also eat Pteropus species. They may also be preyed on occasionally by birds of prey and arboreal snakes. They avoid predation mainly through communal roosting in tall trees. (Tidemann R, 1994)

Ecosystem Roles

Black-eared flying foxes help to disperse fruit tree seeds and fertilize areas around roost trees.

  • Ecosystem Impact
  • disperses seeds

Economic Importance for Humans: Positive

Black-eared flying foxes are important members of their native ecosystems, they are especially important for dispersing tree seeds.

Economic Importance for Humans: Negative

Black-eared flying foxes sometimes eat fruit and may impact fruit crops. ("Australian Museum Online", 1999)

  • Negative Impacts
  • crop pest

Conservation Status

As of 1996 Pteropus melanotus was placed on low risk or least concern on the IUCN Red List. There is a limited number hunted by natives. However, there are concerns that black-eared flying foxes are especially vulnerable because of their restriction to small, oceanic islands and their apparent lack of fear of humans. Black-eared flying foxes also tend to be active during the day, making them easier to hunt than other species of Pteropus. ("UNEP-WCMC Species Database", 1996; "Australian Biological Resource Study", 1999; "UNEP-WCMC Species Database", 1996)

Other Comments

Most of the information that was found is on the subspecies P. m. natalis, with little information on the other five subspecies. ("Australian Biological Resource Study", 1999)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Kyle Steiner (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

Glossary

acoustic

uses sound to communicate

arboreal

Referring to an animal that lives in trees; tree-climbing.

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.

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.

diurnal
  1. active during the day, 2. lasting for one day.
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.

frugivore

an animal that mainly eats fruit

herbivore

An animal that eats mainly plants or parts of plants.

island endemic

animals that live only on an island or set of islands.

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.

oriental

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

World Map

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.

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.

swamp

a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.

tactile

uses touch to communicate

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.

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

2002. "Aging Cell" (On-line). Life history, ecology and longevity in bats. Accessed December 01, 2006 at http://www.blackwellpublishing.com/products/journals/suppmat/ACE/ACE020/ACE020sm.htm.

1998. "Australian Biological Resource Study" (On-line). Australian Government: Department of the Environment and Heritage Home Page On the World Wide Web. Accessed November 03, 2006 at http://eriss.erin.gov.au/cgi-bin/abrs/fauna/details.pl?pstrVol=EUTHERIA;pstrTaxa=140;pstrChecklistMode=2.

1999. "Australian Biological Resource Study" (On-line). RECOVERY OUTLINES AND TAXON SUMMARIES - Christmas Island Flying-fox. Accessed December 01, 2006 at http://www.deh.gov.au/biodiversity/threatened/publications/action/bats/31.html.

1999. "Australian Museum Online" (On-line). Bats in Australia: Christmas Island Flying Fox. Accessed November 03, 2006 at http://www.austmus.gov.au/bats/records/bat7.htm.

2006. "Christmas Island" (On-line). Mammals. Accessed December 01, 2006 at http://www.abc.net.au/nature/island/ep2/locals/4.htm.

1996. "UNEP-WCMC Species Database" (On-line). Accessed November 03, 2006 at http://sea.unep- wcmc.org/isdb/CITES/Taxonomy/tax-species-result.cfm?Genus=Pteropus&Species=melanotus&source=animals&tabname=status.

Michigan Science Art. 2002. "University of Michigan Museum of Zoology: Animal Diversity Web" (On-line). Pteropus (flying foxes). Accessed November 03, 2006 at http://animaldiversity.ummz.umich.edu/site/accounts/pictures/Pteropus.html.

McNab, B., M. Armstrong. 2001. "Journal of Mammalogy" (On-line). SEXUAL DIMORPHISM AND SCALING OF ENERGETICS IN FLYING FOXES OF THE GENUS PTEROPUS. Accessed December 01, 2006 at http://www.bioone.org/perlserv/?request=get-document&doi=10.1644%2F1545-1542%282001%29082%3C0709%3ASDASOE%3E2.0.CO%3B2.

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

Tidemann R, 1994. The Diet of Felis catus on Christmas Island, Indian Ocean. Wildlife Research, 21/3: 279-286.

Wilson, R. 1993. Mammal Species of the World. Washington: Institution Press.