Manly Dam’s Threatened Bird Species
Powerful Owl
Species: Ninox strenua
Conservation Status: Threatened
Powerful Owls are Australia’s largest owls growing to 60cm tall with an impressive wingspan of up to 140cm.
It occurs from eastern and south-eastern Australia (east of the Great Dividing Range), from south-eastern Queensland to South Australia, mostly in large patches of forest. Despite being classified as threatened throughout its range, the Powerful Owl can and does, survive within cities. These owls are found in the suburbs , particularly where bushland remnants are close by such as in Manly Dam. The urban landscape is a hard place to live though! Powerful Owls need big, old trees for nesting and these are in short supply. They usually rest (roost) during the day among dense leafy foliage of trees and shrubs and so protecting this habitat is crucial. These are also top order predators, so protecting their food sources – possums, birds, flying foxes and even Christmas beetles is important. And of course the urban landscape is a risky place. We know that car and glass strikes are the leading causes of mortality for these birds (with estimates in Sydney of 12% of the population dying each year this way).
Species information credit: Birdlife Australia Powerful Owl Project.
Image credits: all Powerful Owl photos courtesy of Sarah Maddox (blog: https://birdsinsydney.wordpress.com)
Birdlife Australia’s Powerful Owl Project has active volunteers in Manly Dam.
Glossy Black-Cockatoo
Species: Calyptorhynchus lathami
Conservation Status: Threatened
Glossy Black-Cockatoos mostly occur in eastern Australia, from south-eastern Queensland to eastern Victoria. One of the colloquial names for the species is the Casuarina Cockatoo, and this arises from the birds’ preferred food: the seeds of the casuarina tree. They strip the seed pods from the tree, then tear them open with their strong bills to extract the seeds — the ground below is often littered with dozens of discarded cones.
The Glossy Black-Cockatoo mates for life, with pairs maintaining their bond all year round. The female prepares the nest hollow and incubates the eggs, only leaving the nest to feed herself after the newly hatched nestling is a week old. Males feed the female and nestling throughout the incubation and brooding period.
Many Dam has a number of groves of casuarina trees these cockatoos feed in. These birds also need tree hollows to rear their young in highlighting the importance of protecting habitats that provide both food trees as well as 100+ year old trees to provide nesting hollows.
Reference: Birdlife Australia