New technology to monitor for endangered corncrakes

RTÉ News​

06-05-2025

New technology has been set up in an area around the Shannon Callows near Athlone, Co Westmeath to monitor for the presence of critically endangered corncrake birds.
The National Parks and Wildlife Service is hoping that this new recording technology will provide more comprehensive information about whether the corncrake has returned to the area.
"What we're using is bio-acoustic recorders and they're placed in strategic locations along the Shannon Callows," explains Therese Kelly, District Conservation Officer with the National Parks and Wildlife Service.
"They are capturing birdsong in the middle of the night, from about 10 o'clock until about maybe five o'clock in the morning," she said.
"What we're interested in hearing, if they're there, are the songs and sounds of corncrakes, which were once common on the callows."
The Shannon Callows are stretches of flat grassland along the shores of the River Shannon between Athlone and Portumna, which flood in winter but dry out in summer.
The area was once a significant breeding ground for corncrakes in Ireland, but their numbers have declined in recent years and with early summer flooding becoming more prevalent, it has impacted the corncrake's breeding success.
It is hoped that the new technology can shed more light on the status of the corncrake in the region compared to traditional surveying methods, which have been used in the past.
"This new technology is recording one minute on, one minute off for the whole night long in a singular location," says Ms Kelly.
"If we had people out doing this survey, we would have to spread that human resource across a large area, which would mean that you could only listen at a location for a much shorter length of time.
"There is a chance, because of that, that you might actually miss a bird.
"It might detect that you're there and stay quiet for the time that you're there, so the bio-acoustic recorder, it's a much less invasive method of surveying for birds."
Detecting the sound of the corncrake
In the coming weeks, the data from the sound recorder will be downloaded and experts working with specially designed software should be able to detect the sound of the corncrake, if it is present.
The monitoring will continue in the Shannon Callows well into the summer and experts will continue to download the data that it records.
The Breeding Waders EIP, an initiative that aims to protect and restore Ireland's most vulnerable breeding wader population, is involved in the corncrakes project.
"We're lending our support to this project by analysing the sound files that come from these audio recordings to determine if there's corncrakes in the area," said Karen Nugent, Communications Manager for the Breeding Waders EIP project.
"It will take a lot of analytics, and a lot of work as there's hours of recordings, but the more you do it, the quicker you get at it."
Corncrakes - shy and elusive
Corncrakes are extremely shy and elusive birds that fly more than 6,000km to Ireland from the Congo region of West Africa to mate and have their young.
Their distinctive call was once a common feature in the Irish countryside.
"This was the heartland of corncrake back in the 1990s and their loss is very much lamented by the farmers and landowners along the callows."
They are small - about the size of a blackbird - and seek cover among plants such as nettles, cow parsley, common hogweed, meadow flowers and some traditionally grown crops like kale.
They begin their breeding cycles while in Ireland and if all goes well, a female corncrake will quietly raise two clutches, with about ten chicks each in each brood, and be gone back to Africa by late August or early September.
Usually, the male is gone even sooner than that.
While they are in Ireland, male corncrakes make a lot of noise.
They have a unique disyllabic crex-crex call to attract a female and to warn other male corncrakes off .their patch.
The male can start at 11pm and "call out" as many as 10,000-15,000 times in a night.
Record number detected in 2024
The corncrake is listed on the Red List of Conservation Concern having significantly decreased in both number and range in Ireland and other European countries.
Last year, the highest number of corncrake territories were recorded in Ireland for 25 years, according to data from the National Parks and Wildlife Service (NPWS).
There were 233 corncrake territories recorded in 2024, which represented a 45% increase since 2018.
Most of the territories recorded in the NPWS survey were in the breeding areas of Galway, Mayo and Donegal; areas that are part of the Corncrake LIFE conservation project..
"The sound of the corncrake is part of the landscape here."
"So at a national level corncrake numbers have steadily increased over the past five years but the number is still quite low," explained Dr John Carey, who manages the Corncrake LIFE project.
"What we're hoping now is that, because we have this population increase, birds which are returning to the west and northwest coast may pass over the Shannon Callows, and then, by extension, some of them might actually stay here," he said.
Ten years since corncrake last detected in area
It has been ten years since a corncrake was detected in the Shannon Callows area and Mr Carey said the loss is keenly felt.
"This was the heartland of corncrake back in the 1990s and their loss is very much lamented by the farmers and landowners along the callows," he added.
"What we're doing in this project is trying to remotely detect those birds and determine the status of the birds here in the callows, because this was an area where the corncrake was quite prevalent," Mr Carey added.
"Our hope now is by monitoring the birds more comprehensively, we can determine their status and then perhaps look at the feasibility of re-introducing them or translocating them back here."
"Those of us who live along the Shannon, as I do, it's something that's missing from our lives. The sound of the corncrake is part of the landscape here," he said.
"It's 10 years since we've had the birds on the callows and along the Shannon system, as so many people would love to hear the bird back and with the help of God, we'll be able to do it."