Free-loaders make their presence felt
A FEW days ago, the first cuckoos for this spring were seen in the Geelong region.
Unless wrens and thornbills are careful, they will soon be raising the cuckoos’ young instead of their own.
These first arrivals are Horsfield’s bronze-cuckoos, birds slightly larger than sparrows but with a slender rather than a chubby build.
They gain their family name from a bronze sheen in the back and wings.
Cuckoos are usually heard before they are seen, for all of the species that visit us each spring have distinctive and quite loud voices.
In the Horsfield’s bronzecuckoo it is a single descending “tseeeuw”, often ending with a sharp, upward note.
Closely related, and quite similar in appearance, is the shining bronze-cuckoo, whose call can best be described as resembling someone whistling to their dog.
Each year we have visits by at least five species of cuckoos, with another two rather rare locally.
All are spring-summer migrants that leave southern Australia in autumn, spending the winter months in northern Australia.
One of the “regulars” is the eastern koel, a bird that has arrived as a summer visitor only the past 10 years or so.
Before that, it was unknown in our part of the world.
All of the cuckoos are parasitic on other birds, laying their eggs in the nests of the species best able to raise their young.
Bronze-cuckoos prefer small birds, such as fairy-wrens and thornbills, while the koels’ preferred hosts are wattlebirds and perhaps magpielarks.
In the past they were disliked, even despised as parasites that foisted their young on to others to raise.
Of course they do, but it is an integral part of the nature of birds. Wildlife information and questions can be sent to ppescott@ optusnet.com.au