Yellow Tailed Black Cockatoos in Ruffy

The Yellow – Tailed Black Cockatoo , conservation status : Not threatened .

Large flocks of these cockatoos are currently feeding in the Strathbogie Ranges . By large  I mean 30+birds travelling together , enjoying social interaction, exploiting food resources and avoiding predators.  Membership of a stable flock allows individuals to use the collective knowledge of the group. The individual food intake of flock members may be lower but this is compensated for by an enhanced food supply over the long-term . Large flocks can be seen in areas where pine plantations have been established, especially where these are close to native forest. This abundant exotic food source may be responsible for their increased numbers. Their main food consists of seeds and the insect larvae of some species of moths and wood-boring beetles.

All cockatoos nest in tree hollows . Unable to excavate their own nesting cavities, birds must choose from those available .The average nest entrance width for these Yellow-Tailed Black  Cockatoos is 27cms and the preferred hollow depth is 171cms. Nest height above ground averages 7 metres. I have never observed  Yellow Tailed Black Cockatoos nesting around Ruffy , prehaps they move deeper into forest areas to find suitable nesting hollows . Breeding is a long and involved process – nest selection, incubation and care of nestlings and juveniles occupy a large portion of the year. Reproductive success is largely dependent on food supply – weather  conditions and predators also play a role.

All cockatoo eggs are white, as hollow nesting birds they have no need for camouflaged eggs.  Yellow-tailed Black Cockatoos typically lay 2 eggs per clutch and the incubation period lasts from 28-31days. The nestling period lasts for 90 days. The hatchlings are covered in bright yellow down .

Reference  : Austalian Natural History Series “Cockatoos” by Matt Cameron.

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