King cobra: Difference between revisions
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The '''King cobra''' (''Ophiophagus hannah'') is the largest [[ | The '''King cobra''' (''Ophiophagus hannah''), also sometimes referred to as '''Hamadryad''' is the world’s largest venomous snake, capable of growing up to {{convert|5.5|m|ft}}, is rare, but has wide a distribution. This monotypic [[genus]] of the family [[Elapidae]] is considered as a species complex, as the species varies in colouration, scalation and body proportion. The King cobra is distributed in [[India]], [[Nepal]], [[Bangladesh]], [[Bhutan]], [[Myanmar]], [[People's Republic of China|China]], and most parts of [[Southeast Asia]] including [[Indonesia]] and the [[Philippines]]. The King cobra is listed under Schedule II of the ''Indian Wildlife Protection Act 1972''; Appendix II of CITES; and in the Vulnerable category by IUCN (2010).This is a very elusive species, rarely seen and rarely bites humans, when it does, however, the mortality rate is generally low. | ||
==Description== | |||
The king cobra is a distinctive snake. It is the world's longest venomous snake, averaging between {{convert|3.1|m|ft}} and {{convert|3.8|m|ft}} in length, but the longest recorded specimen was {{convert|5.85|m|ft}} in length. However, this is very rare and most specimens don't usually grow longer than {{convert|4.3|m|ft}} in length. The London Zoo had one in its collection from Negeri Sembilan (Peninsular Malaysia) that grew to {{convert|5.71|m|ft}} in total length, when it had to be put down at the outbreak of World War II in 1939, to avoid it escaping. Tail length accounts for approximately 20% of the total length of the snake. The body scales are smooth and strongly oblique. The adult is brown or olive above with scales dark-edged especially on tail and posterior body with traces of whitish crossbars. The throat is orange-yellow or cream coloured with irregular blackish markings, and the belly greyish-brown. The belly may be uniform in colour or ornamented with bars. In Myanmar, the banded pattern persists in adults.The young, at least up to about {{convert|60|cm|in}}, is dark-brown or black above with many white or yellow crossbars that are narrow and chevron-shaped with forward-pointing apices. The head is black above with four white cross-bars. The head and body are white below, with the [[ventrals]] and [[subcaudals]] bordered with black. The [[dorsal scales]] are in 15 rows. There are seven [[upper labial scales]], with the third and fourth upper labials in contact with the eye, and the third upper labial touching the posterior nasal. A pair of large and diagnostic [[Occipital scales|occipital shields]] are found behind the [[parietals]], with the occipital shields in contact with each other at the midline. The underside has 215–264 [[ventral scales]], with the [[Anal scale|anal shield]] entire. There are 80–125 [[subcaudal scales]], with the anterior subcaudals single and posterior subcaudals paired. In the field, the king cobra is easily confused with the keeled rat snake (''Ptyas carinata''), but its larger head, smaller eyes, its pair of large occipital shields, and, when harassed, its habit of rearing up the anterior one-third of the body with neck flattened dorso-ventrally, are unmistakable.<ref name=leviton>Leviton, Alan E.; Guinevere O.U. Wogan; Michelle S. Koo; George R. Zug; Rhonda S. Lucas and Jens V. (2003). ''The Dangerously Venomous Snakes of Myanmar''. Illustrated Checklist with Keys. Proc. Cal. Acad. Sci. 54 (24): 407–462</ref><ref name=sp>Lim, Kelvin. Leong, Tzi Ming. Lim, Francis. (2011). [http://rmbr.nus.edu.sg/nis/bulletin2011/2011nis143-156.pdf The King Cobra, ''Ophiophagus hannah'' (Cantor) in Singapore (Reptilia: Squamata: Elapidae)]. ''Nature in Singapore'' (National University of Singapore). '''4:''' 143–156.</ref> | |||
==Distribution and habitat== | |||
===Geographical distribution=== | |||
The king cobra is widespread throughout South and [[Southeast Asia]].<ref name=w&c04>Whitaker, Romulus; Captain, Ashok (2004). Snakes of India: The Field Guide. Chennai, India: Draco Books. ISBN 81-901873-0-9.</ref> It is recorded from [[Pakistan]], [[Bhutan]], [[Nepal]], [[India]] (including the [[Andaman Islands]]), [[Bangladesh]], [[Myanmar]], southern [[China]] (including [[Hong Kong]] and the island province of [[Hainan]]), [[Vietnam]], [[Cambodia]], [[Laos]], [[Thailand]], Peninsular [[Malaysia]], [[Singapore]], [[Indonesia]] in the islands of [[Borneo]] (Sarawak, Sabah, Brunei, and Kalimantan), [[Sumatra]] (including Simeulue, Nias, Banka, Belitung, and Riau Islands), [[Java]], [[Bali]], [[Sulawesi]], and the [[Philippines]] (Dinagat, Luzon, Mindanao, Mindoro, Negros, Jolo, Palawan, and Balabac Islands).<ref name=sp/> | |||
Records of the king cobra from Pakistan seem doubtful, and the population in the [[Western Ghats]] of [[India]] appears to be isolated. Although only ''Ophiophagus hannah'' is presently recognised, there is considerable geographic variation among populations and systematic studies have suggested that a complex of several species is involved.<ref name=sp/> | |||
===Habitat=== | |||
The king cobra inhabits a wide range of habitats. It occurs in jungle and primary and secondary forest, woodlands, and open fields. Its preferred habitat is thick primary forests and estuarine mangrove swamps with heavy rainfall<ref name=w&c04/> and has been reported to occupy humid jungles with thick undergrowth, cool swamps and bamboo clusters.<ref name=JTT>Bashir, T. Poudyal, K. Bhattacharya, T. Sathyakumar, S. Subba, JB. (June 2010). [http://threatenedtaxa.org/ZooPrintJournal/2010/June/o243826vi10990-991.pdf Sighting of King Cobra Ophiophagus hannah in Sikkim, India: a new altitude record for the northeast]. Journal of Threatened Taxa. 2 (6): 990-991.</ref> In terms of altitudinal distribution, this species is known to inhabit from {{convert|150|m|ft}} to {{convert|1530|m|ft}} in Nepal,<ref>Selich, H. & W. Kästle (eds) (2002). ''Amphibians and Reptiles of Nepal.'' Gantner, A.R.G., V.G. Verlag & Ruggell (distributed by Koeltz, Koenigstein, Germany), 1201pp, 127pls. (includ- ing 374 col. figs).</ref> from sea level to {{convert|1800|m|ft}} in Sumatra<ref>David, P. & G. Vogel (1996). ''The Snakes of Sumatra: An Anno- tated Checklist and Key with Natural History Notes.'' Edition Chimaira, Frankfurt-am-Main, Germany, 260pp.</ref> and has been reported up to {{convert|2181|m|ft}} in Mussoori Hills in India.<ref>Waltner, R.G. (1975). Geographical and altitudinal distribution of Amphibians and reptiles in the Himalayas - Part IV. Cheetal 16: 12-17.</ref> | |||
Revision as of 23:59, 23 May 2012
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Binomial name | ||||||||||||||||||||
Ophiophagus hannah (Cantor, 1836)[2][3][4] | ||||||||||||||||||||
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The King cobra (Ophiophagus hannah), also sometimes referred to as Hamadryad is the world’s largest venomous snake, capable of growing up to 5.5 m (18.04 ft), is rare, but has wide a distribution. This monotypic genus of the family Elapidae is considered as a species complex, as the species varies in colouration, scalation and body proportion. The King cobra is distributed in India, Nepal, Bangladesh, Bhutan, Myanmar, China, and most parts of Southeast Asia including Indonesia and the Philippines. The King cobra is listed under Schedule II of the Indian Wildlife Protection Act 1972; Appendix II of CITES; and in the Vulnerable category by IUCN (2010).This is a very elusive species, rarely seen and rarely bites humans, when it does, however, the mortality rate is generally low.
Description
The king cobra is a distinctive snake. It is the world's longest venomous snake, averaging between 3.1 m (10.17 ft) and 3.8 m (12.47 ft) in length, but the longest recorded specimen was 5.85 m (19.19 ft) in length. However, this is very rare and most specimens don't usually grow longer than 4.3 m (14.11 ft) in length. The London Zoo had one in its collection from Negeri Sembilan (Peninsular Malaysia) that grew to 5.71 m (18.73 ft) in total length, when it had to be put down at the outbreak of World War II in 1939, to avoid it escaping. Tail length accounts for approximately 20% of the total length of the snake. The body scales are smooth and strongly oblique. The adult is brown or olive above with scales dark-edged especially on tail and posterior body with traces of whitish crossbars. The throat is orange-yellow or cream coloured with irregular blackish markings, and the belly greyish-brown. The belly may be uniform in colour or ornamented with bars. In Myanmar, the banded pattern persists in adults.The young, at least up to about 60 cm (23.62 in), is dark-brown or black above with many white or yellow crossbars that are narrow and chevron-shaped with forward-pointing apices. The head is black above with four white cross-bars. The head and body are white below, with the ventrals and subcaudals bordered with black. The dorsal scales are in 15 rows. There are seven upper labial scales, with the third and fourth upper labials in contact with the eye, and the third upper labial touching the posterior nasal. A pair of large and diagnostic occipital shields are found behind the parietals, with the occipital shields in contact with each other at the midline. The underside has 215–264 ventral scales, with the anal shield entire. There are 80–125 subcaudal scales, with the anterior subcaudals single and posterior subcaudals paired. In the field, the king cobra is easily confused with the keeled rat snake (Ptyas carinata), but its larger head, smaller eyes, its pair of large occipital shields, and, when harassed, its habit of rearing up the anterior one-third of the body with neck flattened dorso-ventrally, are unmistakable.[5][6]
Distribution and habitat
Geographical distribution
The king cobra is widespread throughout South and Southeast Asia.[7] It is recorded from Pakistan, Bhutan, Nepal, India (including the Andaman Islands), Bangladesh, Myanmar, southern China (including Hong Kong and the island province of Hainan), Vietnam, Cambodia, Laos, Thailand, Peninsular Malaysia, Singapore, Indonesia in the islands of Borneo (Sarawak, Sabah, Brunei, and Kalimantan), Sumatra (including Simeulue, Nias, Banka, Belitung, and Riau Islands), Java, Bali, Sulawesi, and the Philippines (Dinagat, Luzon, Mindanao, Mindoro, Negros, Jolo, Palawan, and Balabac Islands).[6]
Records of the king cobra from Pakistan seem doubtful, and the population in the Western Ghats of India appears to be isolated. Although only Ophiophagus hannah is presently recognised, there is considerable geographic variation among populations and systematic studies have suggested that a complex of several species is involved.[6]
Habitat
The king cobra inhabits a wide range of habitats. It occurs in jungle and primary and secondary forest, woodlands, and open fields. Its preferred habitat is thick primary forests and estuarine mangrove swamps with heavy rainfall[7] and has been reported to occupy humid jungles with thick undergrowth, cool swamps and bamboo clusters.[8] In terms of altitudinal distribution, this species is known to inhabit from 150 m (492.13 ft) to 1530 m (5019.69 ft) in Nepal,[9] from sea level to 1800 m (5905.51 ft) in Sumatra[10] and has been reported up to 2181 m (7155.51 ft) in Mussoori Hills in India.[11]
Cited references
- ↑ Ophiophagus hannah at The IUCN Red List of Threatened Species. Accessed 23 May 2012.
- ↑ Ophiophagus hannah (TSN 700646) at Integrated Taxonomic Information System. Accessed 23 May 2012.
- ↑ Ophiophagus hannah (CANTOR, 1836) at The Reptile Database. Accessed 23 May 2012.
- ↑ Ophiophagus hannah at National Center for Biotechnology Information. Accessed 23 May 2012.
- ↑ Leviton, Alan E.; Guinevere O.U. Wogan; Michelle S. Koo; George R. Zug; Rhonda S. Lucas and Jens V. (2003). The Dangerously Venomous Snakes of Myanmar. Illustrated Checklist with Keys. Proc. Cal. Acad. Sci. 54 (24): 407–462
- ↑ 6.0 6.1 6.2 Lim, Kelvin. Leong, Tzi Ming. Lim, Francis. (2011). The King Cobra, Ophiophagus hannah (Cantor) in Singapore (Reptilia: Squamata: Elapidae). Nature in Singapore (National University of Singapore). 4: 143–156.
- ↑ 7.0 7.1 Whitaker, Romulus; Captain, Ashok (2004). Snakes of India: The Field Guide. Chennai, India: Draco Books. ISBN 81-901873-0-9.
- ↑ Bashir, T. Poudyal, K. Bhattacharya, T. Sathyakumar, S. Subba, JB. (June 2010). Sighting of King Cobra Ophiophagus hannah in Sikkim, India: a new altitude record for the northeast. Journal of Threatened Taxa. 2 (6): 990-991.
- ↑ Selich, H. & W. Kästle (eds) (2002). Amphibians and Reptiles of Nepal. Gantner, A.R.G., V.G. Verlag & Ruggell (distributed by Koeltz, Koenigstein, Germany), 1201pp, 127pls. (includ- ing 374 col. figs).
- ↑ David, P. & G. Vogel (1996). The Snakes of Sumatra: An Anno- tated Checklist and Key with Natural History Notes. Edition Chimaira, Frankfurt-am-Main, Germany, 260pp.
- ↑ Waltner, R.G. (1975). Geographical and altitudinal distribution of Amphibians and reptiles in the Himalayas - Part IV. Cheetal 16: 12-17.