The “devil bird” is on the march from the tropics and it is only a matter of time before it reaches Tasmania.
The common koel has satanic associations principally because of its eerie call which can be heard throughout the night. Another name for it is the “rainbird” because the song can also be heard before and during storms.
The rainbird certainly worked its tricks when I arrived in Melbourne a few weeks ago, a sudden thunderstorm flooding the central city streets. By coincidence, the local press had a report of a recent invasion of koels, birds usually found in a summer range that extends from Far North Queensland to southern New South Wales.
In the past, common koels – members of the cuckoo family – were unknown to Victoria, but sightings have dramatically increased in recent years. Climate change with resulting warmer summers is considered to be the reason.
Reports of koel sightings are still spasmodic but all the same during my annual Melbourne pilgrimage to attend the Australian Tennis Open I kept a look out and my ears attuned in the hope of discovering one of the birds.
Because of warmer temperatures, avian migration patterns have been changing, with birds of the tropics increasingly found in more southerly areas of Australia.
So far I have not heard of any dramatic changes to Tasmanian birdlife but it seems that migratory birds like the koel will soon be arriving.
Migratory birds are particularly vulnerable to changing climate because migrants must time their arrival with the availability of food resources, whether they be flowering plants or emerging insects. Research is now underway to see how the koels might be faring in unfamiliar areas which, for the first time, are offering climatic conditions similar to their usual range.
In Britain, global warming is being attributed to an alarming decline in the population of the only cuckoo species found there, the European cuckoo. The species has fallen in number by 38 per cent, a decline thought to be connected to a decrease in moths, an important food source also hit by warmer, drier weather.
I am familiar with the common koel from my days working in Townsville. It is one of the larger cuckoos – about the size of a magpie – with a blue-black plumage.
Birdlife Australia has so far not collated data on the current koel invasion. Last summer 121 sightings were recorded.
The koels winter in Papua New Guinea and Indonesia before moving south to Australia in late September, returning in March.
If koels eventually arrive here, it will not be the first time the incessant two-note call has been heard in a city park. A few years back a birder who had lived in Townsville reported hearing a koel in Franklin Square. It turned out to be a recording of random bird calls broadcast during a summer festival!