Megabat

Megabats
Fossil range: Oligocene–Recent
Large flying fox, Pteropus vampyrus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Chiroptera
Suborder: Megachiroptera or Yinpterochiroptera
Dobson, 1875
Family: Pteropodidae
Gray, 1821
Subfamilies

Macroglossinae
Pteropodinae
Spectacled Flying-fox (Pteropus conspicillatus)

Megabats constitute the suborder Megachiroptera, family Pteropodidae of the order Chiroptera (bats). They are also called fruit bats, old world fruit bats, or flying foxes.

Contents

Description

The megabat, contrary to its name, is not always large: the smallest species is 6 centimeters (2.4 inches) long and thus smaller than some microbats. The largest reach 40 cm (16 inches) in length and attain a wingspan of 150 cm (5 feet), weighing in at nearly 1 kg (2.2 pounds). Most fruit bats have large eyes, allowing them to orient visually in the twilight of dusk and inside caves and forests.

Their sense of smell is excellent. In contrast to the microbats, the fruit bats do not, as a rule, use echolocation (with one exception, the Egyptian fruit bat Rousettus egyptiacus, which uses high-pitched clicks to navigate in caves).

Behaviour and ecology

Fox Island, Australia, is believed to be the largest colony of flying foxes on the continent

Fruit bats are frugivorous or nectarivorous, i.e., they eat fruits or lick nectar from flowers. Often the fruits are crushed and only the juices consumed. The teeth are adapted to bite through hard fruit skins. Large fruit bats must land in order to eat fruit, while the smaller species are able to hover with flapping wings in front of a flower or fruit.

Frugivorous bats aid the distribution of plants (and therefore, forests) by carrying the fruits with them and spitting the seeds or eliminating them elsewhere. Nectarivores actually pollinate visited plants. They bear long tongues that are inserted deep into the flower; pollen thereby passed to the bat is then transported to the next blossom visited, pollinating it. This relationship between plants and bats is a form of mutualism known as chiropterophily. Examples of plants that benefit from this arrangement include the baobabs of the genus Adansonia and the sausage tree (Kigelia).

Classification

Head of a Masked Flying Fox or Fruit-Bat (Pteropus personatus).
Livingstone's Fruit Bat Pteropus livingstonii
Giant Fruit Bat (Flying Fox) at Columbus Zoo and Aquarium

Bats are usually thought to belong to one of two monophyletic groups, a view that is reflected in their classification into two suborders (Megachiroptera and Microchiroptera). According to this hypothesis, all living megabats and microbats are descendants of a common ancestor species that was already capable of flight. However, there have been other views, and a vigorous debate persists to this date. For example, in the 1980s and 1990s, some researchers proposed (based primarily on the similarity of the visual pathways) that the Megachiroptera were in fact more closely affiliated with the primates than the Microchiroptera, with the two groups of bats having therefore evolved flight via convergence (see Flying primates theory).[1] However, a recent flurry of genetic studies confirms the more longstanding notion that all bats are indeed members of the same clade, the Chiroptera.[2][3] Other studies have recently suggested that certain families of microbats (possibly the horseshoe bats, mouse-tailed bats and the false vampires) are evolutionarily closer to the fruit bats than to other microbats.[2][4]

List of species

The family Pteropodidae is divided into two subfamilies with 188 total species, represented by 43 genera:

FAMILY PTEROPODIDAE

As disease reservoirs

Fruit bats have been found to act as reservoirs for a number of diseases which can prove fatal to humans and domestic animals such as horses. The bats themselves sometimes have no signs of infection.

Researchers tested fruit bats for the presence of the Ebola virus between 2001 and 2003. Three species of bats tested positive for Ebola, but had no symptoms of the virus. This indicates that the bats may be acting as a reservoir for the virus. Of the infected animals identified during these field collections, immunoglobulin G (IgG) specific for Ebola virus was detected in Hypsignathus monstrosus, Epomops franqueti, and Myonycteris torquata.

The epidemical Marburg virus was found in 2007 in specimens of the Egyptian fruit bat, confirming the suspicion that this species may be a reservoir for this dangerous virus.[5]

Other diseases which can be carried by fruit bats include Australian bat lyssavirus and Henipavirus (notably Hendra virus and Nipah virus), both of which can prove fatal to humans.

In popular culture

In the book series Silverwing by Kenneth Oppel, a fruit bat named Java is one of the main characters in the final book of the series. In Stellaluna, a popular children's book by Janell Cannon, the story revolves around the plight of a young fruit bat who is separated from her mother. In The Winjin Pom, a 1991 puppetry-based tv-series by Richard Carpenter and Steve Bendelack, Frazer is an anthropomorphic fruit bat with a laid-back attitude and a taste for fresh fruits. The character of Batty Coda in FernGully: The Last Rain Forest was a fruit bat who had been subjected to laboratory tests by humans and escaped.

Fruit bats are also considered a delicacy by South Pacific Islanders, where consumption has been suggested as a possible cause of Lytico-Bodig disease. [6]

Footnotes

  1. ↑ Pettigrew JD, Jamieson BG, Robson SK, Hall LS, McAnally KI, Cooper HM (1989). "Phylogenetic relations between microbats, megabats and primates (Mammalia: Chiroptera and Primates)". Philosophical Transactions of the Royal Society of London, Series B, Biological Sciences 325 (1229): 489–559. doi:10.1098/rstb.1989.0102. 
  2. ↑ 2.0 2.1 Eick, GN; Jacobs, DS; Matthee, CA (September 2005). "A nuclear DNA phylogenetic perspective on the evolution of echolocation and historical biogeography of extant bats (chiroptera)" (Free full text). Molecular biology and evolution 22 (9): 1869–86. doi:10.1093/molbev/msi180. PMID 15930153. http://mbe.oxfordjournals.org/cgi/pmidlookup?view=long. 
  3. ↑ Simmons, NB; Seymour, KL; Habersetzer, J; Gunnell, GF (2008-02-14). "Primitive Early Eocene bat from Wyoming and the evolution of flight and echolocation". Nature 451 (7180): 818–21. doi:10.1038/nature06549. PMID 18270539. http://www.nature.com/nature/journal/v451/n7180/abs/nature06549.html. "recent studies unambiguously support bat monophyly". 
  4. ↑ Adkins RM, Honeycutt RL (1991). "Molecular phylogeny of the superorder Archonta" (PDF). Proceedings of the National Academy of Sciences of the U.S.A. 88 (22): 10317–10321. doi:10.1073/pnas.88.22.10317. PMID 1658802. PMC 52919. http://www.pnas.org/cgi/reprint/88/22/10317.pdf. 
  5. ↑ "Deadly Marburg virus discovered in fruit bats". msnbc. August 21, 2007. http://www.msnbc.msn.com/id/20382188/. Retrieved 2008-03-11. 
  6. ↑ Monson, C. S.; Banack, S. A.; Cox, P. A. (2003). "Conservation implications of Chamorro consumption of flying foxes as a possible cause of amyotrophic lateral sclerosis-parkinsonism dementia complex in Guam". Conservation Biology 17: 678–686. doi:10.1046/j.1523-1739.2003.02049.x. 

References

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External links