If you are in the north or east of Australia you may have noticed ‘grey toucan-like birds’ (as described by a Sydney friend) in your suburb making ridiculous sounds at all time of the day and night. These birds are actually the migratory Channel-billed Cuckoo (Scythrops novaehollandiae). They are commonly referred to as storm birds as they turn up in summer to breed then head back to New Guinea and Indonesia around March.
They make their presence known with raucous, maniacal crowing and squawking and don’t tend to win many fans, especially if you have one camped outside your bedroom window.
You may have also seen another ‘storm bird’ the Common Koel (Eudynamys scolopacea) again, the incessant calling of the Koel does not endear them to many of their neighbours. Both birds are from the cuckoo family, of which there 13 species in Australia.
The most interesting thing about the cuckoos is that they are parasitic. That’s right – cuckoos lay their eggs in other birds’ nests, leaving the unsuspecting host bird to raise the cuckoo chicks as their own. A winning combination of trickery and parental negligence.
The Channel-billed Cuckoo is the largest parasitic bird in the world. Due to its size it requires a large host nest such as those of Magpies, Currawongs, Crows and Ravens. The female Channel-billed Cuckoo may lay her eggs in more than one nest and even damage existing host eggs as she goes.
The cuckoo chicks share the nest with the host’s chicks but they grow faster, demand all of the food and eventually starve out the others. To avoid being discovered and kicked out of the nest, some cuckoo chicks have even evolved to look very similar to the young of their host. If all goes according to plan the adult host bird will rear a healthy brood of fledglings…only problem is, they’re not hers.
Birds Australia encourage people to record information about Channel-billed Cuckoo behaviour, as not much is known about their ecology. Do you have these birds in your area? If so, visit the Birds in Backyards website to participate in the ongoing survey. And maybe buy yourself some ear plugs.