Kookaburras
The rollicking call of the Laughing Kookaburra is one of the most enduring sounds of the Australian bush. Most people think that the birds are happily chuckling away, but nothing could be further from the truth – their calls are really serious territorial threats to warn off intruders. In fact recent research has shown that the ‘merry king of the bush’ is a much more complex bird than previously thought.
Laughing Kookaburra (Dacelo novaeguineae)
Also called the Laughing Jackass and the Bushman’s Clock, this is the largest of the kingfishers, measuring 41-47cm (16-18") from head to tail. It has a creamy white head with a brown eye stripe, off-white underparts, brown wings and back, and silvery blue flecks over the shoulders. The Laughing Kookaburra is endemic to the east coast of Australia, but has been introduced to Western Australia, Tasmania and other islands. Its diet consists of small snakes, rodents, lizards, worms and insects.
Co-operation and conflict
Kookaburras breed co-operatively, with family members sacrificing their own reproductive effort to help a breeding pair care for eggs, nestlings and/or fledglings. The female usually lays three eggs and begins incubating before the clutch is complete, so that eggs don’t hatch together but at 0-2 day intervals. Research by Sarah Legge has shown that all helpers are not equal, and a group with male helpers produces more fledglings than one with female helpers. The chicks are very aggressive, and because of the size difference the younger chicks are often killed by the larger firstborn. Although co-operative breeding and siblicide seem very strange, considering the success of kookaburras one can only assume that these survival strategies work well.
Blue-winged Kookaburra (Dacelo leachii)
A close relative of the Laughing Kookaburra, the Blue-winged Kookaburra or Howling Jackass measures about 43cm (17") from head to tail. It has a white eye, an off-white head with brown streaks, a large blue patch on the wings and a blue rump. Its call is a startling series of high-pitched, coughing cackles, usually sung in chorus. It lives in northern and northeastern coastal fringes of Australia as well as in New Guinea, and its range overlaps in places with the Laughing Kookaburra. These two kookaburras have similar feeding, mating and nesting habits, and both raise chicks with the aid of auxiliary helpers.
Further information
Our segment was filmed at:
Featherdale Wildlife Park
217 Kildare Road,
Doonside NSW
Phone: (02) 9622 1644
Further reading
Kookaburras: Quarrelsome Comrades by Sarah Legge. Wingspan, June 1999.
