Nine year study shows why scarce wading birds flourish on grouse moors

Click to view a PDF of Waders on the Fringe.

Scientists urge upland land managers to consider crow and fox control to help the recovery of curlew, lapwing and golden plover  following  a new study published  this week in the leading science publication  the Journal of Applied Ecology. 

For nine years scientists from the Game & Wildlife Conservation Trust, a leading research charity, have looked into the effects of predator control on the breeding success of threatened moorland wading birds.  The Upland Predation Experiment, which was undertaken on moorland in Northern England, is one of the longest running studies of its kind ever undertaken.  Although this research was carried out in Northern England, scientists consider that it is also relevant to Scottish uplands too. 

Dr Adam Smith, the Game & Wildlife Conservation Trust’s Director for Scotland, explains, ““The results of this study appear unequivocal and raise important questions as to why wader populations across Scotland are at best just hanging on.  This study suggests that populations are being held back because high quality predator control is being limited to grouse moors.  We therefore consider that the clear cut results of this study support calls for the extension of predator control options in the Scottish Rural Development Programme so that this proven management technique is available to moorland managers across the country and not simply tied to black grouse conservation.” 

The research shows for the first time that the control of common predators such as crows and foxes significantly improves, by more than three times, the breeding success of curlew, lapwing and golden plover – all species of conservation concern.  The results have important implications for the future of bird conservation in the uplands of England and Scotland.

Dr Stephen Tapper, Head of Policy and Public Affairs with the Trust, explains, “If we want to reverse the decline in some bird populations we need to do more than simply improve countryside habitats. Agri-environment schemes on their own, without predator control, seem unable to give rise to an abundance of breeding waders or even bring about a significant improvement in sparse populations.” 

Dr Tapper continues, “Foxes and carrion crows were scarce in many parts of the country a hundred years ago, now they are very common and ubiquitous. Waders flourish on grouse moors because they are protected from the relentless predation by carrion crows and foxes during the breeding season. In the uplands, we cannot expect to maintain populations of vulnerable species like lapwing and curlew without reducing numbers of some predators.”

Populations of common opportunistic predators such as foxes and crows are at an all time high and this research shows that they are hampering the recovery of many much-loved and vulnerable bird species.   The fox population for example, is estimated to be some 240,000 adults and since 1961 the carrion crow population has risen to 1,580,000 breeding adults.

Dr Kathy Fletcher, a senior upland scientist with the Game & Wildlife Conservation Trust and an author of the study, said, “Gamekeepers routinely reduce the number of predators on grouse moors and this is essential for boosting the red grouse population. Our work shows that this also benefits species like lapwing, golden plover and curlew as well. In our experiment we were able to exclude the effects of other moorland management, such as patchwork heather burning (muirburn), so we can be confident our results were attributable solely to predator control.”

Dr Fletcher concludes, “It would be very sad if we lost a significant fraction of our bird life through want of a little wildlife management. The evidence from our research is that such losses are not inevitable and the North Pennines, which is almost entirely managed for grouse shooting and hosts high concentrations of waders, stands as a testament to the difference game management can make to conservation in the uplands.”

END

Picture credit & ©: David Mason.

Photocaption 1: Lapwing and chick - A new study by the Game & Wildlife Conservation Trust in the Journal of Applied Ecology shows that grouse moors support between three to five times as many breeding lapwing, curlew and golden plover. 

Photocaption 2:  Breeding success of ground-nesting birds monitored as part of the Upland Predation Experiment after controlling for site and year effects.

Notes to editor

1. The study titled “Changes in breeding success and abundance of ground-nesting moorland birds in relation to the experimental deployment of legal predator control “ (p263-272) Kathy Fletcher, Nicholas J Aebischer, David Baines, Robin Foster, Andrew N Hoodless is available online in the Journal of Applied Ecology. 
2. The Journal of Applied Ecology is published by Wiley-Blackwell for the British Ecological Society. Contents lists are available at: www3.interscience.wiley.com/journal/117972213/home.
3. The Trust has also published a full colour account of this study titled “Waders on the Fringe” and this can be obtained from the Game & Wildlife Conservation Trust, Fordingbridge, Hampshire,  www.gwct.org.uk or telephone: 01425 652381.
4. The Trust’s nine-year Upland Predation Experiment, carried out on moorland at Otterburn in Northumberland, comprised four plots of land each measuring 12 square kilometres on which bird numbers and breeding success were measured from 2000 to 2008.  Two of the long-term plots in the experiment remained under the same regime for the duration of the project – one had a full-time keeper, while the second provided an unkeepered comparison.  The two remaining plots switched between predator removal and no predator removal, which allowed the researchers to look at breeding success and abundance on the same plots with and without predator control.
5. The breeding success of curlew, golden plover and lapwing was significantly improved by controlling the numbers of some of their predators.  Waders were more than three times as likely to raise a chick on an area with predator control than on an area without.  Breeding numbers of lapwing, golden plover and curlew increased in years following predator control, but declined in other years.
6. The three waders - lapwing, curlew and golden plover - are all species of conservation concern and have been either ‘red’ or ‘amber’ listed because of declining numbers.  A huge swathe of the English uplands is managed for grouse.  These areas have been designated as Special Protection Areas for birds under the European Natura 2000 network of sites mainly because they are home to high concentrations of breeding waders.  The North Pennines SPA for example, which is almost entirely managed for grouse shooting hosts 1,400 pairs of golden plover, 3,930 pairs of curlew and 330 pairs of dunlin. By contrast Dartmoor National Park now has only 3 pairs of curlew and a dozen pairs of lapwing.  
   

Notes to editors

The Game & Wildlife Conservation Trust is an independent wildlife conservation charity which carries out scientific research into Britain’s game and wildlife. We advise farmers and landowners on improving wildlife habitats and we lobby for agricultural and conservation policies based on science. We employ 14 post-doctoral scientists and 50 other research staff with expertise in areas such as birds, insects, mammals, farming and statistics.  We undertake our own research as well as projects funded by contract and grant-aid from Government and private bodies.   The Trust is also responsible for a number of Government Biodiversity Action Plan species and is lead partner for grey partridge and joint lead partner for brown hare and black grouse.

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