The Corella is August's bird of the month.
Genus:
Long-billed Corella: Cacatua tenuirostris
Little Corella: Cacatua sanguinea
Description
There are two species of Corella now calling the Centennial Parklands home. Along with the Cockatoos and Galahs these are among the most intelligent of our birds.
The most common is the Little Corella, a small, white Cockatoo with a blue ring of flesh around the eye and pale pink feathers between the eyes and the beak. It can raise a small crest of white feathers on its head, and, when in flight, has a noticeable yellow wash on the feathers of its underwing and tail.
The Little Corella is known as one of the most playful species in the world, wrestling playfully with each other when feeding on the ground, or swinging on tree branches by their feet or bills when at their roosts.
The other is the slightly larger Long-billed Corella, named for the upper mandible of the beak, which curves much further over the lower. It has a similar blue eye ring and white crest, but has more striking reddish-pink feathers on the face and a distinctive reddish-pink band of feathers across the top of its breast. The yellow wash on the underwing is less noticeable than on the Little Corella.
Distribution:
The Little Corella is the most widespread in Australia, with a number of sub-species in south-western Western Australia and across northern Australia, with most spread through central and inland eastern Australia. From their original inland habitat they have spread in recent decades to occupy much of the east coast as far as Adelaide.
The Long-billed Corella was originally more restricted in its range, being limited to north-western Victoria, eastern South Australia and south-western New South Wales.
While agriculture opened new avenues for expansion of the range of both Corella species, their popularity as cage birds in the 20th century no doubt assisted in building populations along the coast.
Feeding:
Corellas are generally ground feeding birds, eating grass seeds and using their upper bills to dig up roots, bulbs and tubers. In the park environment they feed primarily on introduced grasses and weeds, particularly the bulbs of Onion Grass. The Long-billed Corella has the advantage of being able to more easily reach the deeper bulbs. The signs of their excavations can be seen throughout the park.
At times the Little Corellas may be seen in pines or ornamental Cypress trees feeding on the cones and shredding the foliage in the process.
Their impact on agriculture has led to calls for culling, as has, along with other cockatoos, their playful chewing on timber and electric-wire insulation. However, there are other management methods for various settings that can encourage the birds to move on.
Breeding:
Both species of Corella are thought to form life-long monogamous pairs. Where these species naturally overlap they have been known to interbreed, and with them both sharing the parklands, hybrids are commonly seen.
Breeding season is usually through winter and into spring and can be triggered by a prolonged period of rain leading to a healthy growth in the grasses on which they depend. They nest in tree hollows, preferring eucalypts, and large colonies may form where suitable hollows are available. The nest is a simple pad of wood shavings in the hollow. Both parents prepare the nest, share incubation of the two to four eggs for about 24 days.
The chicks are hatched naked and helpless and are protected and fed by the adults for about 7 weeks before fledging and leaving the nest. The parents will continue assisting with feeding for about another 3 to 4 weeks until the young Corellas can support themselves.
In the Park:
Large flocks, mainly of Little Corellas, can be seen moving around or feeding anywhere in the park. The roosting sites used most often are the trees beside Duck Pond where they gather to noisily dance and play and drop down to the pond to drink.
Feeding flocks can be found on the lawns and playing fields where they can be examined to find the Long-billed Corellas among them, or the confusing hybrids. Long-billed Corellas can be found in smaller flocks feeding on bulbs or roots which are only accessible to their longer bills.
This information was curated by a team of passionate Centennial Parklands volunteers and with the assistance of Volunteer Program and Asset staff. Find out more about our volunteer programs here.