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Common myna

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Common Myna
In Kolkata, West Bengal, India.
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Aves
Order:
Passeriformes
Family:
Sturnidae
Genus:
Acridotheres
Species:
A. tristis
Binomial name
Acridotheres tristis
Subspecies

Acridotheres tristis melanosternus
Acridotheres tristis naumanni
Acridotheres tristis tristis
Acridotheres tristis tristoides

Distribution of the Common Myna. Native distribution in blue, introduced in red.

The Common Myna or Indian Myna (Acridotheres tristis) also sometimes spelled Mynah, is a member of the starling family. It is a species of bird native to Asia with its initial home range spanning from Iran, Pakistan, India and Kazakhstan to Malaysia and China.[2] An omnivorous open woodland bird with a strong territorial instinct, the Myna has adapted extremely well to urban environments.

The Myna has been introduced in many other parts of the world and its distribution range is on the increase to an extent that in 2000 the IUCN Species Survival Commission (IUCN) declared it among the World's 100 worst invasive species.[3] The Myna is one of only three birds in this list of invasive species. It is a serious threat to the ecosystems of Australia.

Description

The Common Myna is readily identified by the brown body, black hooded head and the bare yellow patch behind the eye. The bill and legs are bright yellow. There is a white patch on the outer primaries and the wing lining on the underside is white. The race found in Sri Lanka, A. t. melanosternus is darker than the widespread nominate race. The sexes are similar and birds are usually seen in pairs.[4]

Behaviour

Juvenile begging for food from adult in West Bengal

The calls includes croaks, squawks, chirps, clicks and whistles, and the bird often fluffs its feathers and bobs its head in singing. The Common Myna screeches warnings to its mate or other birds in cases of predators in proximity or when its about to take off flying.[5] Common Mynas are popular as cage birds for their singing and "speaking" abilities. They are believed to mate for life. They breed through much of the year depending on the location, building their nest in a hole in a tree or wall. The normal clutch is 4–6 eggs. The Asian Koel is sometimes brood parasitic on this species.[6]

Like most starlings, the Common Myna is omnivorous. It feeds on insects and fruits and discarded waste from human habitation. It forages on the ground among grass for insects, and especially for grasshoppers, from which it gets the generic name Acridotheres, "grasshopper hunter". It however feeds on a wide range of insects, mostly picked from the ground.[7] It walks on the ground with occasional hops.

Habitat

This abundant passerine is typically found in open woodland, cultivation and around habitation.

Although this is an adaptable species, its population has been decreasing significantly in Singapore and Malaysia (locally called as 'gembala kerbau', literally 'buffalo shepherd') due to competition with its cousin, the introduced Javan Myna.[8]

In Karachi

Urban success

The Common Myna thrives in urban and suburban environments; in Canberra, for instance, 110 Common Mynas were released between 1968 and 1971. By 1991, Common Myna population density in Canberra averaged 15 birds per square kilometer.[9] Only three years later, a second study found an average population density of 75 birds per square kilometer in the same area.[10]

The bird likely owes its success in the urban and suburban settings of Sydney and Canberra to its evolutionary origins; having evolved in the open woodlands of India, the Common Myna is pre-adapted to habitats with tall vertical structures and little to no vegetative ground cover,[11] features characteristic of city streets and urban nature preserves.

The Common Myna (along with European Starlings, House Sparrows, and feral Rock Doves) is a nuisance to city buildings; its nests block gutters and drainpipes, causing water damage to building exteriors.[12]

Invasive species

The IUCN declared this myna as one of the only three birds among the World's 100 worst invasive species.[13] (Other two invasive birds being Red-vented bulbul and European Starling) It has been introduced widely elsewhere, including adjacent areas in Southeast Asia, Madagascar,[14] the Middle East, South Africa, Israel, North America, Europe, Australia, New Zealand and various oceanic islands, including a very prominent population in Hawaii.[2]

The Common Myna is a pest in South Africa, North America, the Middle East, Australia, New Zealand and many Pacific islands. It is particularly problematic in Australia. Several methods have been tried to control the bird's numbers and protect native species.

Australia

In Sydney, Australia

In Australia, the Common Myna is an invasive pest. They are now often the predominant bird in urban areas all along the East coast. In a 2008 popular vote, the bird was named "The Most Important Pest/Problem" in Australia, also earning the nickname "flying rats" due to their scavanging resembling that of rats.[15]

The Common Myna is found naturally throughout Southeast Asia, and was first introduced to Australia in Victoria between 1863 and 1872 into Melbourne’s market gardens to control insects. The bird is likely to have spread to New South Wales (where it is currently most populous) at around the same time, but documentation is uncertain.[16] The bird was later introduced to Queensland as a predator of grasshoppers and cane beetles; the reasons for its original introduction to Victoria is however, lost in history.[16] Currently, Common Myna populations in Australia are concentrated along the eastern coast around Sydney and its surrounding suburbs, with sparser populations in Victoria and a few isolated communities in Queensland.[17]

The bird can live and breed in a wide range of temperatures, though it thrives in hotter regions. Self-sustaining populations of Common Myna have been found in regions of mean warmest month temperature no less than 23.2°C and mean coldest month temperature no less than -0.4°C, implying that the Common Myna could potentially spread from Sydney northward along the eastern coast to Cairns and westward along the southern coast to Adelaide (though not to Tasmania, Darwin, or across the Great Dividing Range to the arid interior regions).[18]

South Africa

In South Africa where it escaped into the wild in 1902, it has become very common and its distribution is greater where human populations are greater or where there is more human disturbance.[19]

Effect on ecosystems and humans

Threat to native birds

Immature at nest, West Bengal

The Common Myna is a hollow-nesting species; that is, it nests and breeds in protected hollows found either naturally in trees or artificially on buildings (for example, recessed windowsills or low eaves).[20] Compared to native hollow-nesting species, the Common Myna is extremely aggressive, and breeding males will actively defend areas ranging up to 0.83 hectares in size (though males in densely populated urban settings tend to only defend the area immediately surrounding their nests).[21]

This aggressiveness has enabled the Common Myna to displace many breeding pairs of native hollow-nesters, thereby reducing their reproductive success. In particular, the reproduction rates of native hollow-nesting parrots in the bush land of eastern Australia have been reduced by up to 80% by the Common Myna (which was even able to out-compete another aggressive introduced species in the area, the European Starling).[20]

The Common Myna is also known to maintain up to two roosts simultaneously; a temporary summer roost close to a breeding site (where the entire local male community sleeps during the summer, the period of highest aggression), and a permanent all-year roost where the female broods and incubates overnight. Both male and female Common Mynas will fiercely protect both roosts at all times, leading to further exclusion of native birds.[21]

Threat to crops and pasture

The Common Myna (which feeds mostly on ground-dwelling insects, tropical fruits such as grapes plums and some berries and, in urban areas, discarded human food)[22] poses a serious threat to Australian blueberry crops, though its main threat is to native bird species.[23]

In Hawaii, where the Common Myna was introduced to control pest armyworms and cutworms in sugarcane crops, the bird has helped to spread the robust Lantana camara weed across the islands’ open grasslands.[24]

References

  1. ^ Template:IUCN2008
  2. ^ a b "Common Myna". Retrieved December 23, 2007.
  3. ^ Lowe S., Browne M., Boudjelas S. and de Poorter M. (2000). 100 of the World’s Worst Invasive Alien Species. A selection from the Global Invasive Species Database. The Invasive Species Specialist Group (ISSG), a specialist group of the Species Survival Commission (SSC) of the World Conservation Union (IUCN), Auckland.{{cite book}}: CS1 maint: multiple names: authors list (link)
  4. ^ Rasmussen, PC & JC Anderton (2005). Birds of South Asia: The Ripley Guide. Vol 2. Smithsonian Institution & Lynx Edicions. p. 584.
  5. ^ Griffin, Andrea S. (2008). "Social learning in Indian mynahs, Acridotheres tristis: the role of distress calls". Animal Behaviour. 75 (1): 79–89. doi:10.1016/j.anbehav.2007.04.008.
  6. ^ Choudhury A. (1998). "Common Myna feeding a fledgling koel". Journal of the Bombay Natural History Society. 95 (1): 115.
  7. ^ Mathew, DN; Narendran, TC; Zacharias, VJ (1978). "A comparative study of the feeding habits of certain species of Indian birds affecting agriculture". J. Bombay Nat. Hist. Soc. 75 (4): 1178–1197.
  8. ^ Bird Ecology Study Group, Nature Society (Singapore): <http://besgroup.blogspot.com/2005/12/ubiquitous-javan-myna.html>. Accessed 25 Oct 2007
  9. ^ Pell, A.S. (1997). "The Ecology of the Common Myna in Urban Nature Reserves in the Australian Capital Territory" (PDF). Emu. 97. Royal Australasian Ornithologists Union: 141–149. doi:10.1071/MU97018. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  10. ^ Pell 1997, p.146
  11. ^ Pell 1997, p.141
  12. ^ Bomford, M. (2002). "Australian research on bird pests: impact, management and future directions" (PDF). Emu. 102. Royal Australasian Ornithologists Union: 35. doi:10.1071/MU01028. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ Lowe S., Browne M., Boudjelas S. and de Poorter M. (2000). 100 of the World’s Worst Invasive Alien Species. A selection from the Global Invasive Species Database. The Invasive Species Specialist Group (ISSG), a specialist group of the Species Survival Commission (SSC) of the World Conservation Union (IUCN), Auckland.
  14. ^ Wilme, Lucienne (1996). "Composition and characteristics of bird communities in Madagascar" (PDF). Biogéographie de Madagascar: 349–362.
  15. ^ ABC Wildwatch
  16. ^ a b Hone, J. (1978). "Introduction and Spread of the Common Myna in New South Wales" (PDF). Emu. 78 (4). Royal Australasian Ornithologists Union: 227.
  17. ^ Martin, W.K. (1996). "The Current and Potential Distribution of the Common Myna Acridotheres tristis in Australia" (PDF). Emu. 96. Royal Australasian Ornithologists Union: 169–170.
  18. ^ Martin 1996, pp.169-170
  19. ^ Derick S. Peacock, Berndt J. van Rensburg and Mark P. Robertson (2007). "The distribution and spread of the invasive alien Common Myna, Acridotheres tristis L. (Aves: Sturnidae), in southern Africa". South African Journal of Science. 103: 465–473.
  20. ^ a b Bomford 2002, p.34
  21. ^ a b Pell 1997, p.148
  22. ^ Pell 1997, p.147
  23. ^ Bomford 2002, p.30
  24. ^ Pimentel, D. (January, 2000). "Environmental and Economic Costs of Nonindigenous Species in the United States". BioScience. 50 (1). American Institute of Biological Sciences: 53–56. doi:10.1641/0006-3568(2000)050[0053:EAECON]2.3.CO;2. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)

Further reading

  • Feare, Chris (1999). Starlings and Mynas. Princeton University Press. ISBN 0-7136-3961-X. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  • Grimmett, Inskipp and Inskipp, Birds of India ISBN 0-691-04910-6
  • Pell, A.S. & Tidemann, C.R. (1997) "The impact of two exotic hollow-nesting birds on two native parrots in savannah and woodland in eastern Australia", Biological Conservation, 79, 145-153. A study showing native birds being excluded from up to 80% of nesting sites in Canberra, Australia.
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