The crankiness of sleep-deprived east coast Australians driven “insane” by what they call a “devil bird” keeping them up through the night is palpable on the Reddit thread dedicated to the problem of the koel’s midnight calls.
Many on the thread were quick to come to the defence of the bird whose cooee calls they said heralded the Australian summer.
A migratory bird, the koel usually arrives in Australia from Papua New Guinea and Indonesia to breed from late September to early October each year, when the male will sing his advertising call day and night to attract a female.
However, a heightened exasperation this year could be justified as the bird’s calls have continued later into the year than is usual due to climatic conditions, according to experts.
Prof Gisela Kaplan, an expert in Australian native birds, said the koel’s breeding season “definitely seems longer than it has been at any other time”.
“The night calling here [in Coffs Harbour] has gone on and on and on for weeks now, which suggests that the male tends to come earlier than the females.”
The females, Kaplan said, may have postponed their arrival in Australia because of the weather patterns in the countries they come from, such as flooding in Indonesia.
The flooding in Australia could have also postponed females who she said have a “remarkable” ability to predict climatic change and make adjustments to their breeding in order to ensure the survival of their offspring.
“Birds seem to understand what’s happening in the environment and how that connects to food availability.”
Koels, which are a cuckoo species leaving their eggs in the nests of other birds to feed them, will know that the local bird species like currawongs and magpies will be struggling to find proteins, which have disappeared in soils due to flooding.
Sean Dooley, the national public affairs manager at Birdlife Australia, said data showed that this year the arrival of koels appeared to be later than usual.
He said two databases, Birdlife Australia’s Birdata and E-bird, used by many birdwatchers, showed a “drastic” reduction in reports of koels at the usual time they arrive, with the reporting rate also showing a significant drop.
In New South Wales, a reporting rate of 13.5% in October 2021 dropped to 9.3% for the same period this year, according to Birdata.
Meanwhile, the E-bird data showed that the usual peak of koel sightings in NSW occurred two weeks later than usual.
“The peak reporting rates sit at about 20% most years … but this year we didn’t hit that 20% rate until two weeks later than usual, so not until the last week of October,” Dooley said.
Koels were identified through their calls rather than sightings most of the time as he said they were a “cryptic species rarely seen as they do tend to stick to the densest foliage”.
Dooley also attributed the change to weather conditions, leading koels either to arrive later or not to make their territorial breeding calls because the conditions weren’t right for them yet to breed.
He said overall the numbers on the east coast had remained stable but there appeared to be increasing numbers in inland Australia, in areas such as Canberra and Victoria where they were “virtually unknown until this century”.
Kaplan said that if the koels this year “persist long enough, they may well succeed” in breeding “but perhaps not in such large numbers”.
She said although there was often the perception in evolution that species were resilient, “you only need a few seasons where it was simply not prudent for the birds to try to breed” which can cause “tipping points” for species decline to dangerous levels.
Dooley’s advice for dealing with the calls through the night?
“They’re pretty hard to drown out, but really they’re one of our few native species that are doing well.
“So I’d suggest just you need to learn to love that sound.”
