Thursday, 5 February 2015

Koel fledglings

A Koel fledgling is fed by its foster parent - a Red Wattlebird

It's now late summer in Canberra and there are lots of young birds about. So when I heard some loud begging calls from a young bird outside my study window I took a quick look around the back garden, and sure enough I found what I thought I would - a young Common Koel Eudynamys scolopacea. Or rather I found two, one a couple of weeks older than the other.

Common Koels are a species of cuckoo which migrate south to Australia to breed in the southern summer. Then in the autumn, they fly back north to south-east Asia, to the Indonesian archipelago or some other islands in that region. Their full migration and range is not fully understood. With a length of about 450 mm, they are a large cuckoo, the Common Cuckoo Cuculus canorus of Europe is about 330 mm, which is about the length of this bird's foster parent, a Red Wattlebird Anthochaera carunculata (350 mm). So it is a scale up from the European cuckoo.


The older fledgling was a well marked golden bird

The older fledgling had a wonderful golden plumage, with a bold black eyestripe and yellow crown. The younger bird was much less colourful, with a dull grey eyestripe and buff crown.


The younger fledgling - showing how pale its plumage was compared with that of the older bird

Both chicks were being fed by Red Wattlebirds, but I know that another pair of wattlebirds that feed in our garden have raised two broods of their own young this year. Were the Koel chicks both from eggs laid by the same female Koel? If so, the Koel female managed to dupe at least two out of three Wattlebird pairs in our local patch.

Other species used as hosts in south-east Australia that live in the Canberra area are Noisy Friarbirds Philemon corniculatus, although there are none of those around our garden this year; and Magpie Lark Gralina cyanoleuca, but the local pair do not seem to have been parasitised. Virginia Abernethy, who is studying Koels has never found either of these host species used in Canberra either. It seems that the Koels have local specialties in which host species they use.


The younger fledgling begs for food from its busy foster parent


And it received food - of course, what parent could deny such a plea

It was a great opportunity to compare the plumages of the two birds, one older than the other, not by much, but so different in colouring. The older bird was ready to go on with life on its own. It wouldn't be dependent on its foster parents for much longer. Although as I write this a day later, I can still hear both birds calling.


The older fledgling continued to beg too, with a deeper call, and it was fed less frequently


Young Koels often walk through the branches rather than fly

The adult Koels have gone quiet recently now that they stopped breeding for this year. And as they are migratory they will soon be flying north on their annual migration, closely followed by youngsters like these two. I wonder where they will fly to, all alone with no parents to guide them, but with an innate ability to find the species' tropical habitat.


This bird was fully fledged and probably well able to feed for itself - time to go - what a splendid tail

2 comments:

  1. Hi Stuart. Your shot of the young Koel walking through the branches shows the Zygodactyl foot structure. Difficult to observe in living birds, except for bird banders. ;)

    ReplyDelete
  2. Yes Denis, tthe feet are a bit blurred as the bird moved so quickly, but the two-toed grasp is clearly seen in the hind foot, and the two by two spread of the toes is clearly shown on the raised front foot. A perfect illustration of zygodactyl foot structure. Well spotted, and thank you for sharing the point with us. S.

    ReplyDelete