Blyth's flying fox (Pteropus melanotus)

With its big, round eyes and long snout, Blyth’s flying fox (Pteropus melanotus) is aptly named for its fox-like face. The large ears have well-rounded tips and are black, hence its alternative common name of black-eared flying fox ⁽²⁾.

The coat colour of Blyth’s flying fox depends on the island it inhabits. In general, those from the Nicobar Islands have a brown head and reddish body, while the inhabitants of Andaman Island tend to have a black head and brown body with grey stripes ⁽²⁾. Individuals on Christmas Island typically have blackish or dark brown fur, peppered with greyish-white hairs, and a slightly paler wash on the back of the neck ⁽⁴⁾.

Male and female Blyth’s flying foxes do not differ in size ⁽⁴⁾, but females tend to be darker than males ⁽²⁾. 

Also known as

Black-eared flying fox, Christmas Island flying fox.

Synonyms

Pteropus edulis, Pteropus modiglianii, Pteropus natalis, Pteropus niadicus, Pteropus nicobaricus, Pteropus tytleri.

Spanish

Zorro Volador De Andaman.

Size

Forearm length: 153 mm ⁽²⁾

Average weight: 600 g ⁽²⁾

Blyth’s flying fox lives in huge colonies of up to several thousand members ⁽²⁾. Unlike many other bats, Blyth’s flying fox is largely active during the daytime, emerging from these large roosting colonies long before dusk to feed ⁽¹⁾. Blyth’s flying fox feeds on wild and cultivated fruit, as well as flowers ⁽¹⁾. Its role as a pollinator and disperser of seeds for many native trees makes it a key species in the island ecosystems it inhabits ⁽⁵⁾.

The annual breeding season begins around September, and a single young is born after a gestation period of five months, with most births occurring between December and February ^{(4) (5) (6)}. Blyth’s flying fox has a complex polygamous mating system, where a small number of males mate with a large number of females ⁽⁵⁾. Like other Pteropus species, it is probable that the female leaves the main roosting colony after mating, forming a smaller maternity group with other females ⁽⁷⁾.

The young Blyth’s flying fox clings to its mother’s fur as she travels between roosting and foraging areas. When the pup gets a little older, it is left at the roost site while the female forages, until it is able to fly ⁽⁵⁾. Female Blyth’s flying foxes reach sexual maturity at around 6months, while males do not reach maturity until 18 months ⁽²⁾.

Blyth’s flying fox occurs only on islands in the northern Indian Ocean. It inhabits the Nicobar and Andaman Islands (India), Nias Island (Indonesia) and Christmas Island (Australia) ⁽¹⁾. It used to also exist on Enggano Island (Indonesia), but this population is believed to have been wiped out by a severe hurricane ⁽¹⁾.

Blyth’s flying fox forages throughout the islands’ habitats ⁽⁴⁾, but typically roosts in mangrove vegetation ⁽²⁾. However, on Christmas Island, where there are no mangroves, it roosts in semi-deciduous rainforest ⁽⁵⁾.

Blyth’s flying fox is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾ and is listed on Appendix II of CITES ⁽³⁾.

Habitat loss is one of the greatest threats to Blyth’s flying fox, as the islands’ natural habitats are converted to agricultural land, developed for tourism-related activities, or subject to logging ⁽¹⁾. Blyth’s flying fox may also be impacted by hunting, either for food or for traditional ‘medicines’ ^{(1) (5)}.

The Christmas Island population of Blyth’s flying fox is considered to be the most threatened. Numbers of Blyth’s flying fox have declined drastically here – from an estimated 6,000 individuals in 1984 to about 1,500 in 2006. The exact reasons for this decline are not clear, but it is likely due to a combination of factors, including predation by feral cats and hunting for food ⁽⁵⁾. The yellow crazy ant (Anoplolepis gracilipes) has caused significant damage to the wildlife of Christmas Island since its introduction in the early 1900s. Yellow crazy ants may directly disturb, displace or kill Blyth’s flying fox, and they also affect its food supply, by reducing fruit production and even killing fruiting trees ⁽⁵⁾.

Climate change is likely to impact Blyth’s flying fox by affecting forest and wetland ecosystems ⁽⁵⁾. The Intergovernmental Panel on Climate Change (IPCC) expects that climatic changes will stimulate more extreme weather events, including higher temperatures, greater rainfall and increased frequency and severity of tropical cyclones ^{(8) (9)}.Extreme weather events, such as tsunamis and severe cyclones, are likely to cause further damage to the habitat of this species, especially in coastal areas and on low-lying islands ^{(1) (4) (9)}. It is thought that the population of Blyth’s flying fox on Enggano may have been wiped out by a severe hurricane ⁽¹⁾.

Blyth’s flying fox is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning that international trade in this species should be carefully monitored ⁽³⁾. This endangered species also occurs in a number of protected areas throughout its range, including the Campbell Bay protected area on Great Nicobar Island, and the National Park which covers over 60 percent of Christmas Island ⁽¹⁾.

There are no specific measures in place for Blyth’s flying fox, but efforts are being made to control invasive species on Christmas Island, including the yellow crazy ant ⁽⁵⁾. Further action is clearly needed for this threatened bat, particularly on Christmas Island, if it is to persist. Considering the critical role Blyth’s flying fox plays on Christmas Island, as a pollinator and seed disperser, its extinction would have devastating consequences for the ecosystems of the island, and therefore its conservation should be considered the highest priority ⁽⁵⁾.

Find out more about bat conservation:

• Lubee Bat Conservancy:
  http://www.batconservancy.org/

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

This species information was authored as part of the Arkive and Universities Scheme.

Feral

Previously domesticated animals that have returned to a wild state.

Gestation

The state of being pregnant; the period from conception to birth.

Pollinator

An animal that in the act of visiting a plant’s flowers transfers pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant.

Polygamous

Mating with more than one partner in the same season.

Semi-deciduous rainforest

Rainforest that is dominated by semi-deciduous plants - plants that lose their foliage for a very short period.

1. IUCN Red List (November, 2010)
   http://www.iucnredlist.org/
2. Bates, P.J.J. and Harrison, D.L. (1997) Bats of the Indian Subcontinent. Harrison Zoological Museum Publications, Sevenoaks.
3. CITES (November, 2010)
   http://www.cites.org/
4. Beeton, R.J.S. (2008) Pteropus melanotus natalis (Christmas Island Flying-fox) Listing Advice. Threatened Species Scientific Committee, Canberra. Available at:
   http://www.environment.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=64801
5. James, D.J., Dale, G.J., Retallick, K. and Orchard, K. (2007) Christmas Island Flying-Fox, Pteropus natalis Thomas 1887: An Assessment of Conservation Status and Threats. Parks AustraliaNorth Christmas Island Biodiversity Monitoring Programme: Report to Department ofFinance & Administration and the Department of Environment & Water Resources,Canberra.
6. Mickleburgh, S.P., Hutson, A.M. and Racey, P.A. (1992) Old World Fruit Bats: An Action Plan for their Conservation. IUCN/SSC Chiroptera Specialist Group, Gland, Switzerland.
7. Nowak, R.M. (1991) Walker’s Mammals of the World. The Johns Hopkins University Press, Baltimore and London.
8. Intergovernmental Panel on Climate Change (April, 2011)
   http://www.ipcc.ch/
9. United Nations Economic and Social Commission for Asia and the Pacific (2000) Ministerial Conference on Environment and Development in Asia and the Pacific – Climate Change and the Pacific. Kitakyushu, Japan.