The fan-tailed cuckoo left me hanging in suspense this winter when it failed to show as it always does, towards the end of August.
Migrants arriving late, and sometimes not at all, always gives cause for concern at a time of declining bird numbers but I had no need to worry about this species of cuckoo which is generally common in the Hobart area.
I had received reports that the familiar descending, trill of the cuckoo had been heard in other places, birds apparently deciding to overwinter instead of migrating back to the mainland at the end of summer.
The fan-tailed cuckoo is usually my harbinger of spring along with the striated pardalote, which can usually be heard in mid-August. They arrive about two weeks before the more popular bird that heralds the new season, the welcome swallow.
I display mixed feelings about the four species of cuckoo that visit Tasmania in summer. They are all beautiful birds but I’ve never been able to reconcile their elegance with the anti-social behaviour they display during the breeding season.
I describe them as the sociopaths of the bird world, laying their eggs in the nests of other birds and relying on these surrogate parents to raise their young.
The cuckoos arrive early to synchronize their mating with that of their hosts, which are often resident species and early nesters.
After pairing up, the cuckoo females – attracted by the males’ far-carrying calls which tend to dominate the soundscape of the woods – scout grasslands, shrubs and trees for the breeding territories of their surrogates. They watch for mating rituals, nest building and then the females laying eggs. As soon as the female leaves the nest to drink or feed, the cuckoos nip in and lay an egg of their own, the chick eventually ousting its “siblings”.
The fan-tailed cuckoo, with a pink breast contrasting with a grey back, is the second biggest of the cuckoos visiting Tasmania. It’s about the size of a blackbird with the biggest, the pallid cuckoo, a few centimetres larger.
The two smallest cuckoos are sparrow-sized and they have a bronze tinge to bright green feathers, which gives them their name of shining and Horsfield’s bronze-cuckoos.
Once the female cuckoos have deposited the single egg in the nests they choose, their job as parents is done.
There is no sadder sight in nature than in late spring and early summer seeing small birds like scarlet robins and black-headed honeyeaters struggling to feed cuckoo young, which in the case of the fan-tailed and pallid cuckoos are considerably larger than their “parents”.
One species, though, has learned to outsmart the cuckoos. Researchers have discovered individual superb fairy-wrens can identify rapidly growing cuckoo young. When this happens, the fairy-wrens desert the nest and move on to build another, leaving the cuckoo chick to die.