S'N'A Intermediate Series: Episode 25 - Madagascan Giant Hognose Snakes (Leioheterodon)

Snakes ‘N’ Adders Intermediate series
Episode: 25
Madagascan Giant Hognose Snakes
(Genus Leioheterodon)
 
Giant Hog noses are incredibly popular snakes. Sadly this popularity is not yet translating into captive bred off spring. Sure babies are produced but not as regularly as one may imagine for animals that on the face of it are actually relatively easy to cater for.
 
Three species are recognised (we will do further taxonomy and histories later)
Madagascan Giant Hognose (Leioheterodon madagascariensis)
Madagascan Speckled Hognose (Leioheterodon geayi)
Madagascan Blonde Hognose (Leioheterodon modestus)
 
All three species are endemic to Madagascar. The giant Hognose may have been introduced to the Comoros Islands and is also found on some small Islands off Madagascar including Nosy Be.
 
All tree species occur in the same areas. The Giant Hognose is the most widespread with near the whole island populated including the mountainous regions. This includes elevations up to 1500m or more above sea level. Points to huge levels of adaptability. All four localities used here can be applied to this species.
 
The speckled Hognose occurs on the Coastal areas of the South West of the island and in the surrounding hills from 0-1000m above sea level. The nearest conurbation we could find for data is Toliara.
 
The Blonde Hognose has a slightly more confusing distribution with populations on the extreme Southern tip, around Toliara in the South West same as the Speckled, in the centre of the Island just North East of the capital Antananarivo, plus further distributions heading north and on the North Western Coast. The nearest conurbation we could find for data is Mahajanga. Predominantly they seem to occur in dry forest regions or mountainous plateaus.
 
Despite these distributions all three species are relatively easy to care for in captivity. Even imported animals will feed readily on defrost prey. Granted they may not strike but will hoover up. Confidence grows in time. Full disclosure these are imported animals, occasional examples become available in the UK as captive bred but wild caught or captive hatched are more common place.
 
The main difference we have found is prey types accepted. Giant hognoses roundly ignore mice as adults but wolfed rats down, where as Blondes and speckled accepted mice readily but were not interested at all in rats of appropriate size.
These snakes are ready feeders and it is easy to create obese animals, care must be taken not to over do it with food. Esspecially when the staple diet is far fattier than in nature.
 
Visually both Giant Hognoses and Blonde hognoses are identical regardless of sex. Speckled Hognoses (geayi) do vary. Males are darker anteriorly with almost black pigmentation and prominent markings, females lack the darker complexion. We sexed out over 20 animals and after the first 4 we could call the sex visually by colour and was 100% right. Certain texts discuss older animals darkening. We have females here larger than the males approaching 48 inches in length and no dark pigment has formed. This is suggestive of younger animals being born without the darker saddles and males develop over time.
 
Minimum adult size enclosure for the geayi and modestus would be a 48x18x18 vivarium, preferably a 48x24x24.
 
madagascariensis would require 60x24x24 preferably.
 
They are active diggers and enjoy exploring their enclosures. Heating would be best provided from above via a Ceramic heat emitter coupled to a reliable thermostat. Lighting can be provided separately and can take the form of either a led strip or a UVB bulb such as the shade dweller from Arcadia. Substrate potentially for all the animals could either be lignocel, orchid bark or one of the many particulate mixes available from UK wholesalers mixed with coir or top soil to add body. The mix can be relatively dry with either the provision of a dampened hide stuffed with moss or a moss box in which to retire. Shedding in this instance won’t be an issue.
 
Basking temperatures want to be around 30°C on the platform immediately beneath the heater giving the snake opportunity to move away down to around 24-25°C.
 
Night Time Basking temperatures can drop safely to 25°C without issue with the cooler end dropping further.
 
Leioheterodon are egg layers producing litters of up to 20 eggs in exceptionally large females (madagascariensis) – average litters between 6-12 are the norm. Eggs of the giant are large robust eggs that further inflate throughout incubation. a substrate mix of 4:1 at a temperature of 28°C. Hatching occurs from 55-65 days. Babies are volatile and will accept dropped prey they are too threatened by your presence initially to feed from tongs. Some resistance to initial feeding is possible but they soon kick in. Just be patient.