Rinkhals

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Rinkhals
Rinkhals2.jpg
Hemachatus haemachatus
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Hemachatus
Fleming, 1822
Species: H. haemachatus
Binomial name
Hemachatus haemachatus
(Bonnaterre, 1790)
Synonyms

The rinkhals (Hemachatus haemachatus), also called the ringhals or ring-necked spitting cobra, is a venomous elapid species found in parts of southern Africa. It is not a true cobra in that it does not belong to the genus Naja, but instead belongs to the monotypic genus Hemachatus. However, it is closely related to the true cobras and is considered to be one of the true spitting cobras.[3]

Description[edit]

Coloration varies throughout its distribution area, but a characteristic of the species is the belly is dark with one or two light-coloured crossbands on the throat. Their average length is 90–110 cm.[3] Some individuals may have a mostly black body, while others are striped. Rinkhals scales are distinct from those of true cobras in that they are ridged and keel-like.

A South African rinkhals with hood spread

Scale pattern and distribution[edit]

Scalation:[4]

Distribution[edit]

This species is found in the Southern Cape province of South Africa, northeast through the Free State, Lesotho, Transkei, Kwazulu Natal, South Africa, Western Swaziland and parts of Gauteng, South Africa. An isolated population is centered around Inyanga on the Zimbabwe-Mozambique border.[3]

Behaviour and diet[edit]

The rinkhals has a varied diet. Its main prey is toads,[4] but it also eats small mammals, amphibians, and other reptiles.[6]

Rinkhals are unique amongst African cobras in being ovoviviparous.[3] They give birth to 20–35 young, but as many as 65 young have been recorded.[4]

Venom[edit]

The venom of the rinkhals is neurotoxic and partially cytotoxic, and is less viscous than that of other African elapids.[3] When confronting a human, it generally aims its venom at the face. If the venom enters the eyes, it causes great pain.[6]

Symptoms of a bite[edit]

Local symptoms of swelling and bruising is reported in about 25% of cases.[3] General symptoms of drowsiness, nausea, vomiting, violent abdominal pain, cramps and vertigo often occur, as does a mild pyrexial reaction.[3][6]

Defensive behaviour[edit]

If distressed, the rinkhals spreads its hood, showing its distinctive, striped neck. It is a spitting snake, and can spray its venom up to 2.5 m. Its spitting mechanism is primitive and it has to rear up and fling its body forward to spray its venom. It is also known to fake death by rolling onto its back with its mouth agape.

Habitat[edit]

The rinkhals generally prefers grassland habitats because it allows them to blend in with the surroundings. Rinkhals also may live in swamps around southern Africa.[6]

References[edit]

  1. ^ Boulenger, G.A. 1896. Catalogue of the Snakes in the British Museum (Natural History). Volume III., Containing the Colubridæ (Opisthoglyphæ and Proteroglyphæ)... Trustees of the British Museum (Natural History). London. p. 389.
  2. ^ The Reptile Database. www.reptile-database.org.
  3. ^ a b c d e f g S. Hunter (2000). "Venomous Reptiles". 
  4. ^ a b c R. Mastenbroek (2002). "Rinkhals". 
  5. ^ Branch, Bill. 2004. Field Guide to Snakes and Other Reptiles of Southern Africa, Third Revised edition, Second impression. Ralph Curtis Books. Sanibel Island, Florida. 400 pp. ISBN 0-88359-042-5.
  6. ^ a b c d B. Branch (1988). Field Guide to the Snakes and Other Reptiles of southern Africa. Struik, Cape Town.