Noisy, Migratory, Parasitic… Channel-billed Cuckoos

By Keith Hutton on October 19, 2010 in Other

Channel-billed Cuckoos are big, impressive birds. They have been regarded as uncommon migrants in Sydney, which visit to breed from around September to March. However, in recent summers in the Eastern Suburbs they have not been uncommon at all. There are numerous good places to listen and look for them around the local area, particularly in big old trees in parks and along roadsides, especially, it seems, where there is a prevalence of figs. They attract attention because of their repeated trumpeting calls.

They are usually heard in the tops of large trees long before they are seen as they are habitually shy, but noisy. They have an unmistakeable call that has been described as a loud, raucous, rising shout that is sometimes heard at night but most often in the early morning and evening. They are very large, grey cuckoos with huge pale-tipped bills. Adults are mostly grey with bold dark scalloping to the upper body and upper wings, and a slender tail with a dark terminal band and white rounded tip. They often call in flight, frequently harassed by crows and other birds, when they appear high up as a distinctive silhouette resembling a flying cross with a long slender body, prominent head and neck, a massive bill, and a very long, narrow tail and long, pointed scythe-shaped wings.

Channel-billed Cuckoos normally prefer rainforest, open forest, woodlands, farmland and roadsides wherever there are tall fruiting trees. They are breeding migrants from Indonesia and PNG and spend the summer in the north and east of Australia where they range south to about Shoalhaven. Breeding is parasitic and in the Sydney area the preferred hosts are Pied Currawongs. More than one egg is laid in the nest of the host, and sometimes one pair of currawongs rears two or three young cuckoos, at the expense of their own babies.

Adult Channel-billed Cuckoos roost away from feeding sites, which they fly to early in the day and where they eat mainly the fruits of native trees, especially figs. They also eat other fruits and vegetable matter, and some seeds, insects, and occasionally eggs and young birds. Single birds, pairs or small groups feed in the outer foliage of large fig trees in our region, where they may be very noisy or remain quiet for hours. They often stay all day after feeding, and just sit around and preen or remain motionless for long periods.

Channel-billed Cuckoos are generally common and conspicuous within their range and may have benefited from land clearing and a consequent increase in host species to rear their young. Certainly in the Sydney region they are commoner now than in the past, as are the Pied Currawongs, which have benefitted from exotic berry trees planted in suburban areas.

While some birds may die as a result of collisions with reflecting windows, overall it appears that Channel-billed Cuckoos are doing well in the Eastern Suburbs, largely due to adequate food availability and improved child-minding facilities.