Cape bird snake

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Cape bird snake
Vine Snake (Thelotornis capensis) (6011690147) .jpg

Cape bird snake ( Thelotornis capensis )

Systematics
Subordination : Snakes (serpentes)
Superfamily : Adder-like and viper-like (Colubroidea)
Family : Adders (Colubridae)
Subfamily : True snakes (Colubrinae)
Genre : Thelotornis
Type : Cape bird snake
Scientific name
Thelotornis capensis
Smith , 1849

The Cape bird snake ( Thelotornis capensis ), also known as the savannah bird snake , is a species of the snake (Colubridae) and belongs to the genus of the liana snake ( Thelotornis ). It was first described in 1849 by the British zoologist Andrew Smith.

features

The Cape bird snake has a very slender body with striking camouflage and an elongated head. It reaches a total length of between 60 and 130 cm, with no gender difference in body length. Her eyes have horizontally slit pupils with which she can see stereoscopically . These special adaptations for snakes, which were probably developed for hunting in thin branches, were otherwise only developed by snakes of the genera Ahaetulla in Asia and Oxybelis and Uromacer in Central and South America, with which the Cape bird snake is not closely related.

The jaw has furrowed, back standing poison teeth (so-called opistoglyph dentition), which characterizes the species as a false snake. The tongue is orange with black tips. In the nominate form Thelotornis capensis capensis , the rostral scutum and nasal scutum (nasal shield) are barely visible from above. There are usually two lorealia , a preocular shield, three postocular shields, one or two temporal shields , mostly eight supralabial shields (scutum supralabiale) and usually 19 rows of dorsal scales. Males have 144 to 160 abdominal scales (Scutum ventrale) and 133 to 155 subcaudal scales (Scutum subcaudale), females 148 to 162 abdominal scales and 127 to 147 subcaudal shields. In Thelotornis capensis oatesi 150 177 ventral scales are available. Males show 132 to 173, females 126 to 168 subcaudal shields. The scutum anale (anal shield) is divided.

Way of life

The species is diurnal and leads a tree-climbing way of life. In the event of danger, she inflates her throat, whereby the otherwise concealed neck markings on the intercalated skin becomes visible. In this position, the head is also flattened.

The species reproduces through oviparity , i.e. laying eggs. The eggs are narrow and elongated in shape. The clutch contains 8 to 10 eggs.

The prey spectrum of Thelotornis capensis mainly includes lizards such as chameleons , but also other snakes , small mammals , birds and frogs . It approaches its prey slowly rocking and with motionless outstretched tongue, which serves as a lure for lizards. Although it is very well adapted to hunting in trees, it also catches prey on the ground.

toxicology

Thelotornis capensis produces a hemotoxic and hemorrhagic effective snake venom , further various effects on hemostasis comprising (blood clotting). Internal bleeding and kidney failure can occur as a result of a poison bite. Severe cases of poisoning by this species are rare, but several deaths are known, for example that of the famous herpetologist Robert Mertens . The coagulative enzymes activate prothrombin (which is converted into thrombin ) and the Stuart-Prower factor (factor X). In addition, a weak acceleration of fibrinolysis is described. The antivenin against the poison of the Boomslang ( Dispholidus typus ) could not demonstrate any effectiveness against the toxin of the Cape bird snake. Treatment is symptomatic.

Occurrence

The distribution area extends in eastern Africa from southern Somalia south to the north of Namibia and South Africa . Thickets, sparse stands of trees and dead trees in the savannahs, coastal areas and on the edges of forests are populated. The populations are stable, the species is not threatened and can be found frequently in many places.

Systematics

The following three subspecies are described:

  • Thelotornis capensis capensis ( Smith , 1849)
  • Thelotornis capensis oatesi ( Günther , 1881)
  • Thelotornis capensis schilsi Derleyn , 1978

Thelotornis capensis mossambicanus , the fourth subspecies to be found in the literature, is now listed as a separate species Thelotornis mossambicanus .

Individual evidence

  1. ^ A b Richard Shine, Peter S. Harlow, William R. Branch, Jonathan K. Webb: Life on the Lowest Branch: Sexual Dimorphism, Diet, and Reproductive Biology of an African Twig Snake, Thelotornis capensis (Serpentes, Colubridae) . In: Copeia . tape 1996 , no. 2 , 1996, p. 290-299 .
  2. ↑ a b Thelotornis capensis in The Reptile Database ; Retrieved April 18, 2012.
  3. ↑ a b c IUCN Red List: Thelotornis capensis
  4. ↑ a b Chris Mattison: Encyclopedia of the Snakes . blv Verlag, 2007, ISBN 978-3-8354-0360-4 .
  5. ↑ Clinical features of twig snake (Thelotornis capensis) envenomation . PMID 7444704
  6. ^ Thelotornis mossambicanus in The Reptile Database

literature

  • Mark O'Shea: Venomous snakes. All species in the world in their habitats. Franckh-Kosmos Verlag, 2006. ISBN 3-440-10619-5 .
  • Dieter Schmidt: Atlas snakes . Nikol-Verlag, (bede-Verlag, 2006), ISBN 978-3-86820-011-9 .

Web links