Indonesian Autumn Adder

The Indonesian Autumn Adder (Vipera berus) is one the most fascinating species of adders. Not true to their name the Indonesian Autumn Adder can be in Indonesia but also in Central Africa – Congo, south-west Uganda, and west Kenya.  The Indonesian Autumn Adder is one of the prettiest (if not the prettiest) snakes on the planet.

Indonesian Autumn Adder – Name

Known also as the bush viper, rough-scaled bush viper, spiny bush viper, hairy bush viper,

Indonesian Autumn Adder – Statistics

Length: 50-65cm. Females are larger than the males.

Indonesian Autumn Adder – Physical Description

Adders are relatively short and robust with large heads and a rounded snout. The red-brown eyes have vertical elliptical, rather then round, pupils – a feature of all venomous snakes. Males are usually a grey or buff colour with vivid black markings, although they can also vary from silver to yellow or green in colour. Females are brown with dark red-brown markings that are less prominent than in the males. Both sexes have a zigzag pattern running along the back with a / or X-shaped marking at the rear of the head, although this zigzag pattern may be replaced by a straight brown stripe with dark spots on either side. Adders have black undersides. Melanistic (black) individuals sometimes occur in mountainous regions.

Indonesian Autumn Adder – Venom

Not much is known about their venom except that it is mainly neurotoxic. Besides the neurotoxins, they also carry cytotoxins and fasciculins. Toxicity of individual specimens within the same species and subspecies can vary greatly based on several factors, including geographical region.

Even the weather and altitude can influence toxicity (Ernst and Zug et al. 1996). A bite can be fatal to humans without access to proper first aid and subsequent antivenom treatment. Until recently, their venom has often been regarded as less toxic than that of many other species, perhaps because bites are uncommon, but this turned out not to be the case. There are now a number of reports of bites that have led to severe hemorrhaging of internal organs.

Indonesian Autumn Adder – Distribution

The Indonesian Autumn Adder isn’t just found in Southern Asia. In short, adders are one of the most widespread species of snake. The Indonesian Autumn Adder is distributed in Central Africa and parts of Southern Asia.

Indonesian Autumn Adder

Indonesian Autumn Adder – Habitat

Adders occupy a variety of habitats, including open woodland, hedgerows, moorland, sand dunes, riverbanks, bogs, heathland and mountains. They prefer undisturbed countryside and can be found in surprisingly wet habitats throughout the summer months.

Indonesian Autumn Adder – Diet

Indonesian Autumn Adders use venom to immobilize prey such as lizards, amphibians, nestlings and small mammals. After striking their prey, they will leave the venom to take effect before following the victim’s scent to find the body. This is an economical way of hunting, avoiding any damage that could be caused by struggling with prey.

Indonesian Autumn Adder – Behavior

Indonesian Autumn Adders are active during the day, spending time basking until their body temperature is high enough to hunt for food. In some of the hotter countries of their range, they may emerge at dawn and dusk to avoid the intense heat. Mating takes place between April and May, with males often fighting for females. They rear up at each other and try to push the head of their opponent onto the ground. Eventually, one male will give up and search for another mate. Indonesian Autumn Adders hibernate from September to March when temperatures dip below nine degrees Celsius, often using deserted rabbit or rodent burrows, or settling under logs. They sometimes hibernate communally. Males emerge 2-5 weeks before the females and shed their skin before setting off in search of females.

Indonesian Autumn Adder – Reproduction

Males follow the females around until she allows them to copulate with her. This takes place in April-May. Adders have a 3 to 4 month gestation period and are one of the few snakes that are viviparous (give birth to live young). In late August females give birth to between 5 and 20 live young, although usually the number is between 6 and 10. The young remain close to their mother for a few days, before going off in search of food. Females do not breed on consecutive years, as they do not have time to build up sufficient fat reserves to produce another set of young from one breeding season to the next.

Indonesian Autumn Adder – Conservation status

Indonesian Autumn Adders are protected under the Wildlife and Countryside Act 1981 from being killed, injured or sold.

Notes
Adders are not aggressive snakes, and will only attack if harassed or threatened. Although an adder’s venom poses little danger to a healthy adult human, the bite is very painful and requires urgent medical attention.

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