Hen harrier population suffers decline in Scotland

Louise Cullen

Wednesday 28 June 2017

  • Latest hen harrier survey reveals Scottish population of 460 breeding pairs, a fall of 9% since the last national survey in 2010.
  • Scotland holds 80% of UK harriers, but only Orkney and the Hebrides have not seen a decline in numbers over last six years.
  • Low numbers mean harriers are extremely vulnerable to the effects of habitat degradation, and in some areas, wildlife crime.

Hen harrier numbers have fallen by 9% in Scotland since 2010, according to the latest national survey of these birds, with the total population now estimated to be less than 500 breeding pairs.

The fifth national hen harrier survey was carried out in 2016 by the RSPB, Scottish Natural Heritage (SNH) and the Scottish Raptor Study Group, along with a range of other UK partners (1), and covered the whole of the United Kingdom and the Isle of Man.

In Scotland the results revealed a drop in breeding pairs to only 460, compared with 505 pairs from the previous survey in 2010. The UK population is now estimated at 545 breeding pairs.

This is the second successive decline in the Scottish hen harrier population revealed by national surveys, signalling a worrying trend (2). In the longer term, over the last 12 years, the number of breeding pairs has dropped by 27% in Scotland.

Known for their majestic skydancing ritual, hen harriers are one of the most threatened birds of prey in the country (3). Independent research (4) has identified illegal killing as one of the main constraints on this species, along with a changing climate and the loss of heather moorland and other suitable nesting habitat to commercial afforestation and overgrazing.

Scotland is still a major stronghold for hen harriers, with 80% of the UK population. However, having a breeding population of fewer than 1000 birds makes this species vulnerable to the effects of habitat degradation and, in some areas, wildlife crime. The west Highlands continue to provide a home for the majority of Scotland's breeding harriers (estimated 175 breeding pairs), while Orkney and the Hebrides were the only areas of the country to show a slight increase in the number of these birds.

According to the survey, similar hen harrier declines have been witnessed in all other parts of the UK as well. In England, these birds are on the brink of extinction as a breeding species, with the population falling from 12 pairs in 2010 to only four pairs last year. Meanwhile, Wales saw the number of pairs fall by more than a third over the past six years, from 57 to 35, and Northern Ireland recorded only 46 pairs in 2016 compared with 59 in 2010.

Duncan Orr-Ewing, Head of Species and Land Management at RSPB Scotland, said: "The hen harrier is an indicator of the health of our upland environment, and the fact that its population continues to decline is of major concern. The hen harrier is a high priority for our conservation work and urgent steps need to be taken to tackle illegal killing of this species and to improve their moorland breeding habitats."

Eileen Stuart, SNH's Head of Policy & Advice,said: "While Scotland remains the stronghold for hen harriers in the UK, the continuing decline is a serious concern particularly the low numbers found in parts of the mainland. We're committed to continuing to work with a wide range of partners to tackle wildlife crime through PAW Scotland, including initiatives such as Heads up for Harriers, and General Licence restrictions where evidence supports such action. Scottish Natural Heritage and Forestry Commission Scotland have set up a joint Raptor Working Group to identify and promote the opportunities of forestry for raptors, including hen harriers, to sustainably deliver Scottish Government environmental and forestry policy."

Wendy Mattingley, from the Scottish Raptor Study Group, said:"There is a very concerning trend of a long term decline in the number of breeding hen harriers in Scotland. For the population to begin to recover and expand over all suitable habitat, the intensively managed grouse moors of east and south Scotland must produce successful breeding hen harriers again. The hen harrier is a wonderful spectacular raptor and more action must be taken to ensure that its future is secure."

Tim Baynes, Director of the Scottish Moorland Group, said:"Scotland is still the UK stronghold for the hen harriers by a huge margin. However, it is disappointing to see any indication of decline in Scotland - and much larger drops in Wales and Northern Ireland - even though the decline is regarded by the survey team as statistically insignificant. Harrier breeding fluctuates annually for many reasons - not all associated with wildlife crime. For example, 2016 was a poor year largely due to low vole numbers in Scotland with weather and predation shown to have played their part. Fifteen of our members, covering an area of 325,000 acres, will be working with the Heads Up for Harriers project again this year to better to understand the reasons for poor harrier breeding and to help rebuild the harrier population."

Simon Wotton, lead author of the study, said: "This survey required a monumental effort from a number of different funders, organisations and volunteers - without their help, dedication and expertise we wouldn't be able to build up this accurate picture of these magnificent birds of prey. We hope these results will convince everyone in a position to help hen harriers to take positive steps to ensure their protection and rebuild the country's population for people to enjoy for generations to come."

1. The fifth national hen harrier survey was carried out across the UK from the beginning of April to the end of July 2016 as a partnership between the RSPB, Scottish Natural Heritage (SNH), Natural Resource Wales (NRW), Natural England (NE), the Scottish Raptor Study Group, the Northern Ireland Raptor Study Group, Northern England Raptor Forum and Manx BirdLife. It was co-funded by SNH, NRW and RSPB with the fieldwork being carried out by expert licensed volunteers and professional surveyors from the RSPB Centre for Conservation Science. We welcome also the support of the many landowners and farmers in facilitating this survey.

2. Hen harrier national surveys are carried out every six years. The results from 2010 show a decline of 20% in the preceding six years and the latest results show there has been a second successive drop of 9% between 2010 and 2016.

3. Hen harriers used to be far more widespread in Scotland, and across the rest of the UK, before they were pushed to the brink of extinction in the 19th century.

4. The Hen Harrier Conservation Framework - a report by the Joint Nature Conservation Committee (JNCC): http://jncc.defra.gov.uk/pdf/jncc441.pdf

5. The RSPB is working to secure a future for hen harriers in the UK through the part EU-funded Hen Harrier LIFE Project. Running until 2019, the programme involves satellite tagging, on the ground monitoring, nest protection and investigations work. Learn more at: www.rspb.org.uk/henharrierlife

6. PAW Scotland (Partnership for Action Against Wildlife Crime in Scotland) are working to better understand the threats facing Scotland's hen harriers, and ultimately promote recovery of the species, by working in partnership with land managers through their Heads Up for Harriers project. Learn more at: http://www.gov.scot/Topics/Environment/Wildlife-Habitats/paw-scotland/what-you-can-do/hen-harriers

7. The number of territorial pairs and changes in the numbers of territorial pairs between 2010 and 2016:

2010 terr pairs

2016 terr pairs

% change

% of UK loss

England

12

4

-67

9.1

Scotland

505

460

-9

51.1

Wales

57

35

-39

25.0

N Ireland

59

46

-22.0

14.8

UK

633

545

-14

Isle of Man

29

30

+3

UK & Isle of Man

662

575

-13

Tagged with: Country: Scotland Topic: Birds of prey