King brown snake (Pseudechis australis)

Also known as: king brownsnake , mulga snake, orange-bellied brown snake, yellow-bellied brown snake
Synonyms: Cannia australis aplini, Cannia australis burgessi, Cannia australis newmani, Cannia weigeli, Denisonia brunnea, Naja australis, Pailsus rossignolii, Pailsus weigeli, Pseudechis cupreus, Pseudechis darwiniensis, Pseudechis denisonioides, Pseudechis platycephalus, Pseudechis rossignolii, Pseudechis weigeli
GenusPseudechis (1)
SizeLength: 1.5 - 2.7 m (2) (3)
Top facts

The king brown snake has yet to be classified on the IUCN Red List.

Considered to be Australia’s most common and widespread venomous snake (2) (3) (4), the king brown snake (Pseudechis australis) is a stocky species with a broad head (3) (4), large eyes (3) and a rounded muzzle (5).

Despite its name, the king brown snake is not a true brown snake, all of which belong to the Pseudonaja genus (2), and it is instead named for its typical colouration. The back of the king brown snake is pale to mid-brown, reddish-brown or dark olive (2) (3) (4) (6) (7), becoming paler on the sides (4), while the underparts are generally yellow, orange (5) (6) (7) or pinkish (4). The scales of the king brown snake are smooth (3) (5) (6) and overlap each other (5), and those on the back may be marked with a black tip or black border (4). Being such a drab colour is essential for enabling the king brown snake to be as inconspicuous as possible when on open ground (8).

The king brown snake, also known as the mulga snake because of the mulga grassland habitat which this snake frequently inhabits (2), has two grooved fangs in the front of its mouth, and some smaller, solid teeth further back (5) (6). This species is highly venomous (4) (7), and is thought to be the cause of the greatest number of venomous bites in Australia (9), although these are rarely fatal (2).

The king brown snake is widespread in Australia (1), being found across most of the mainland except for the extreme south and the east coast (2) (3) (4). This species has also been reported in southern New Guinea (1) (2) (3) (6), although there is speculation that this particular population could actually represent a separate species (3).

A highly adaptable species (2), the king brown snake is able to occupy an incredibly wide range of habitats (2) (3), from tropical rainforests to savannah and deserts (2) (3) (4). While this reptile can be found in most habitats on the Australian continent, it is not found in very cold or very humid climes (8).

The king brown snake may be active by day or night, depending on the climate (3) (4), and is known to feed on frogs, birds, small mammals and even other reptiles (2) (3) (4), including lizards (2).

When threatened, the king brown snake tends to flatten its neck, spreading it into a hood-like shape, before raising its body into an arch and striking rapidly (2) (3). The venom produced by this species is extremely toxic, causing lightheadedness, headaches, nausea, vomiting, muscle weakness and mild paralysis in humans (9) (10).

Until relatively recently, it was thought that all large Pseudechis species were live-bearing snakes, but most, including the king brown snake, have since been found to be oviparous, meaning that they lay eggs (11). The female king brown snake has been recorded to lay between 4 and 19 eggs per clutch (2). While no information is available on incubation periods in the wild, clutches of king brown snake eggs laid in captivity have been known to incubate for between 85 and 88 days at higher temperatures, and for shorter periods at lower temperatures (12).

At present, there are no known threats to the king brown snake.

There are currently no conservation measures known to be in place for the king brown snake.

Find out more about reptile conservation in Australia:

Find out more about conservation in Australia:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:

  1. ITIS Catalogue of Life (April, 2013)
  2. O’Shea, M. (2008) Venomous Snakes of the World. New Holland Publishers, London.
  3. O’Shea, M. and Halliday, T. (2010) Reptiles and Amphibians. Dorling Kindersley Ltd, London.
  4. Mattison, C. (2006) Snakes. HarperCollins UK, London.
  5. Krefft, G. (1869) The Snakes of Australia: An Illustrated and Descriptive Catalogue of All the Known Species. Government Printer, South Africa.
  6. de Rooij, N. (1970) The Reptiles of the Indo-Australian Archipelago. Brill Archive, Leiden, The Netherlands.
  7. Krefft, G. (1862) Two Papers on the Vertebrata of the Lower Murray and Darling; and on the Snakes of Sydney. Reading and Wellbank Printers, New South Wales, Australia.
  8. Cermak, M. (2008) Spectacular Snakes of Australia. CSIRO Publishing, Collingwood, Australia.
  9. Barceloux, D.G. (2012) Medical Toxicology of Natural Substances: Foods, Fungi, Medicinal Herbs, Plants, and Venomous Animals. John Wiley & Sons, Hoboken, New Jersey.
  10. Daly, F., Cadogan, M. and Little, M. (2011) Toxicology Handbook. Elsevier Australia, Chatswood, New South Wales.
  11. Khanna, D.R. (2004) Biology of Reptiles. Discovery Publishing House, New Delhi, India.
  12. Bush, B. (1995) Captive reproduction in Pseudechis australis (Serpentes: Elapidae) from Western Australia, and notes on other Pseudechis species. Herpetofauna, 25(1): 30-32.