Western brown snake Pseudonaja nuchalis


Pseudonaja nuchalis, commonly known as the western brown snake or gwardar, is a species of very fast, highly venomous elapid snake native to Australia. Its colour and pattern are rather variable, depending largely on its location. Some experts assert that the western brown's wide variation in appearance and extensive distribution mean that the western brown species in fact covers multiple related, but separate species with three derivative species now officially recognised, P. nuchalis, P. aspidorhyncha, and P. mengdeni

The name gwardar is a word meaning "go the long way around" in an Aboriginal language. This may be regarded as advice for people who come across the species in the wild: that is, while P. nuchalis is generally cautious, shy and inclined to retreat rather than attack, it will defend itself if cornered.


The western brown snake grows up to 1.8 m (5.9 ft) in total length (including tail). Its back can feature shades of orange-brown with flecks and bands, or appear plain. Its belly is cream to orange with pink blotches. Some individuals have jet black heads (this can cause it to be confused with the black-headed python), while others feature a black 'V' shape on the back of their neck, below their head.

Distribution and habitat

The western brown has a wide distribution and is found across most of the Australian continent, including all of the Northern Territory, as well as most of Queensland, Western Australia, and some of Victoria

The western brown is a ground dwelling snake which prefers drier habitats but is also found in coastal eucalypt forests, woodlands, and grasslands. Although the western brown is not an arboreal species, it is not uncommon for it to climb small shrubs or trees. It also hides in crevices and under rocks, and in urban areas can be found under rubbish or tin piles.


P. nuchalis preys upon small mammals and reptiles, including lizards and mice

Lifespan and reproduction

Little is known about the western brown's lifespan. Mating season is roughly from September to November and the female usually produces around 11-14 eggs, but may produce up to 38.

Venom and symptoms

Although the western brown snake's venom is not the most toxic in the brown snake genus, its average delivery contains a relatively high quantity of venom, and thus the western brown snake has high potential to deliver a deadly bite. Its venom contains neurotoxins, nephrotoxins, and a procoagulant, although humans are not usually affected by the neurotoxins. The bite is usually painless and difficult to see due to their small fangs. Human symptoms of a western brown snake bite are headache, nausea/vomiting, abdominal pain, severe coagulopathy, and sometimes kidney damage. In dogs and cats, paralysis is also likely to occur.


The western brown snake is known to be very aggressive when disturbed or threatened, but like most snakes, will usually prefer to retreat from danger. It may develop nocturnal habits during the warmer months but is otherwise active during the day and enjoys lots of sunlight. The Western Brown snake has also been known to practise cannibalism, although this is not common. Western brown snakes kill their prey with a combination of venom and constriction.