While this shot is slightly blurry, it does capture a unique moment between a foster mother honeyeater and her ‘adopted’ Eastern Koel chick. The Eastern Koel’s natural mother exited the honeyeater eggs/fledglings from their rightful place and deposited her own egg in the honeyeater’s nest. Being so much larger than normal honeyeater fledglings, and requiring so much extra food, the chick tricks its foster mother by chirping incessantly as if it was a number of her own broad. The Koel’s are part of the Cuckoo family and it is common practice to leave their young in another bird’s nest while they continue to ‘trip the light fantastic’.
Juvenile Eastern Koel chick demanding food from its adopted Little Wattlebird mother.
The juvenile Eastern Koel I have been tracking for Birdlife Australia (a public survey to learn more about the Koel’s habits) seems healthy and happy, growing steadily under the dutiful care of its ‘adopted’ mother the Little Wattlebird. Like most cuckoos the Eastern Koel lays its egg in another birds nest and on hatching the juvenile Koel pushes any other eggs/fledglings out and becomes the sole recipient of food. Much needed given it grows much bigger than its new parent.
Hearing what I thought was a distressed chirping two days ago I was drawn outside to find this large juvenile Eastern Koel seeking shelter in the inner foliage of a Banksia tree. It looked like it was being dive-bombed by Honeyeaters and they appeared to be aiming at the chick’s face while it squawked back in terror. Apart from the chirping which is a universal young bird trait, its colour scheme of barred and spotted brown body and black line through the eye identified it as a juvenile Eastern Koel under 3 months (when it changes into adult plumage). While it was a good size its chest feathers still have the fluffy look of a young bird.
The Eastern Koel is a long-tailed cuckoo and the adult male is black and the female black/brown, fully grown they sit between 39cm-46cm. As adults they make a very loud ‘kook-kook-kook’ sound and I listened hopefully for the parents in the hope they were out searching for their chick. Eventually it flew off deeper into the Moonee Beach Nature Reserve, but when I awoke the next day it was back cheeping in the same tree.
I initially believed that the Honeyeaters were being aggressive because I had read that the Eastern Koel commandeers their nest and I assumed the Honeyeaters must have evicted it. However, like the Channel-billed Cuckoo, it seems Eastern Koel’s lay their egg/s in the nest of host families alongside the hosts eggs. When the cuckoo chick hatches it pushes the rightful eggs and chicks out, becoming the sole recipient of the food.
At some point the chick, now much larger then the adopted parents, sets off out into the world. But the foray is only a transition as it demands that the parents still feed it. Hence the incessant cheeping I can hear. The chick, who is now four times (at least) the size of its ‘parents’ has them foraging for food. My sympathy now lies with the over worked Honeyeaters who are feeding the bird that destroyed their own young. I wonder at what point they will say it is enough.
Acknowledgement: The Slater Field Guide to Australian Birds, 2nd ed.