The publication of a recent survey of the hen harrier in Ireland has shown that the number of breeding pairs has declined by a third in seven years.
The survey, confirmed that only 85 confirmed pairs of hen harrier were recorded throughout the country by the survey, which Birdwatch Ireland has called “the most severe decline of any national survey to date”.
While there is a current national hen harrier population estimate of 85 to 106 breeding pairs, this represents a decline of one-third (33%) in the total population since the 2015 national survey which previously recorded 108-157 pairs.
Birdwatch Ireland also stated that at the “current rate of decline, population extinction could be expected within 25 years and there could be fewer than 50 breeding pairs of hen harrier remaining within the next 10 years”.
The national survey of hen harriers was carried out in 2022, and was undertaken by a partnership of the Golden Eagle Trust, Irish Raptor Study Group and BirdWatch Ireland on behalf of the National Parks and Wildlife Service (NPWS).
John Lusby of BirdWatch Ireland said: “We have reached crisis point at this stage, the situation could not be more serious, and we need to act accordingly if we are to stand any chance of ensuring hen harriers don’t become extinct within our lifetimes.”
Lusby explained the decline is “primarily driven by land-use changes resulting in the loss of habitat for Hen Harrier in our uplands”.
These land use changes, Lusby said, included “afforestation on important habitats for hen harrier and other wildlife inside and outside the Special Protection Area network, as well as associated disturbances from forest management activities and other pressures including wind energy developments”.
Oonagh Duggan, head of advocacy with BirdWatch Ireland said that “all national hen harrier breeding and wintering sites must be protected from afforestation, forest management activities and wind energy development.
“Habitat restoration for these important areas is also critical and we need long-term and well-funded agri-environment scheme to support farmers for their conservation efforts”.
“We will be launching a campaign soon so that members of the public can offer support to save the skydancing hen harrier from extinction,” Duggan added.
Hen harrier survey
Birdwatch Ireland stated that the survey received “enthusiastic support” from voluntary surveyors including birdwatchers, farmers, wildlife rangers, foresters and biologists, along with the 250 fieldworkers who dedicated over 7,700 hours to the survey.
Jamie Bailey of the Irish Raptor Study Group (IRSG) said that “many IRSG members having surveyed the species for many decades noted that so many of these areas that once were strongholds for the species now appear functionally extinct for the hen harrier”.
Nationwide, surveyors identified three main sectoral pressures across breeding hen harrier sites:
- Forestry;
- Wind energy development;
- Agriculture.
The national survey detailed that “negative effects of activities associated with these sectors typically manifest directly on the species” through nest destruction, disturbance, or displacement.
Surveyors in the Nagles mountains in Co. Cork confirmed that the population of hen harriers “has been lost”.
They reported that the condition of supporting habitat for hen harrier deteriorated significantly over the past 10 years and vast tracts of the Nagles “are now covered in mature forest,” and that “former large areas of rough grassland around the perimeter have since been reclaimed for dairy farming”.
In the Slieve Blooms region, surveyors reported “agricultural intensification and grazing (under- and over-) and agricultural fertilisation as affecting hen harrier and altering their distribution and abundance”.
The mechanical removal of peat and installation of utility and service lines (e.g. power-lines, pipelines) are also leading to increased human activity and further fragmentation and loss of habitats in the region and are considered by surveyors to be affecting breeding hen harriers in the Slieve Blooms.