Leioheterodon

Malagasy Hognose Snakes

Introduction

A genus of three snakes, all of which are found on Madagascar. L. grayi is restricted in range but the other two are widespread, and indeed L. madagascariensis is the most commonly seen snake on the island.

The genus is characterised by an upturned rostral scale, thereby granting them some resemblance to the North American Hognose Snakes, Heterodon. All are oviparous. L. madagascariensis and L. modestus seem to have a preference for frogs and lizards and take a while to acclimatise to a diet of mice in captivity, but in the wild also take birds and small mammals so are probably not to be considered dietary specialists, unlike some of the North American Heterodon species which prey almost exclusively on toads. Prey is seized but instead of being constricted in the usual way (ie by the snake coiling around it) is pressed against the ground before being swallowed.

Henkel and Schmidt consider both L. madagascariensis and L. modestus to be easy captives and L. madagascariensis to be an ideal snake for a life in captivity.

	QUICK INDEX
L. grayi	L. madagascariensis	L. modestus

Species	Common Name	Distribution	Size	Notes
Leioheterodon
L. grayi	Speckled Hognose?	SW Madagascar	Avg 3'/90cm?	Wright describes this as the calmest of the three species in his experience. The measurements given for this species are based on his observations of about 20 animals in addition to his own. Scalation: rostral scale less pronounced than in the other two members of the genus. Coloration: dorsally brown with pale edges to the scales; ventrally brown. Reproduction: no details so far available.
L. madagascariensis	Checkered Hognose?	Madagascar (coastal regions and Nosy Bé and Nosy Sakata), Comoro Islands	Max 5'/150cm, avg 4½'/135cm	L. madagascariensis is catholic in its habitats, but prefers to be near water and is more usually found at lower altitudes. It is also a follower of civilisation, being found in the vicinity of human settlements: this, and its diurnal activity, account for its common appearance. The species is usually calm but if provoked will put on a hissing and throat-flattening display before biting. Henkel & Schmidt note that the species has no venom, which is interesting in the light of Wright's observation on the effects of a bite from L. modestus (see below) Scalation details: large and heavy rostral; ridged supraocular shields over eyes; anal scale undivided. Coloration: dorsally black on front third including head but with yellow sides, changing to checkered yellowish-brown with a yellow-black zig-zag marking usually along back, and then black towards the posterior;. ventrally mostly yellow with black half-moon-shaped spots. Hatchlings similar but slightly darker. Reproduction: a clutch of 7-13 eggs (usually up to 10) is laid.
L. modestus		Madagascar	Max 4½'/135cm, avg 3'/90cm	L. modestus is similar adaptable in its habitat but prefers dried out riverbeds with residual water or areas around small ponds. Like L. madagascariensis it is also a follower of civilisation, where its occasional predation of young poultry makes it unpopular. Henkel & Schmidt claim that this species has no venom. However, Wright noted that the bite of this snake on a colleague had mildly unpleasant effects which lasted for 2 hours, including numbness of the right arm, slight dizziness and shallow breathing, although there were no permanent after-effects. Scalation: heavy rostral; prominent supraocular shield. Coloration: dorsally uniform beige or pale brown; ventrally very pale brown with a pearly sheen. Reproduction: Allen obtained a clutch of 7 eggs in 1993, of which 2 were viable and hatched.

Bibliography

Amphibians and Reptiles of Madagascar and the Mascarene, Seychelles and Comoro Islands, Friedrich-Wilhelm Henkel and Wolfgang Schmidt, Krieger, Florida 2000.

"The Malagasy Hognose Snakes, Genus Lioheterodon", Adam Wright, Reptilian Volume 3 Number 3, 1995. A brief overview of the genus with useful breeding and incubation data from the author's own experience.

Links

Back to Colubrid Snakes | Back to Snakes | Back to Reptiles | Back to Home Page