Tipping Points - a guest blog by David Jarrett

In Strathbraan and Glenshee once the evenings start to draw out, if you know where to look you can find Curlew amidst neat rows of saplings, beaks probing exposed moundings, still gamely trying to breed at sites which have been given over to tree planting. At Tarras Valley, there’s been no predator control for years - the waders remain but they won’t be getting many fledglings away and the populations will be ageing. Glen Dye had lots of waders, then an insurance company planted trees for carbon credits. At Glen Prosen, the trees aren't in the ground yet, but the gamekeepers were stood down by the Scottish Government last year. At Kinrara and Dalnacardoch there were never that many waders, but the keepering was part of a wider network of estates where predator control created productive breeding areas along the bottoms of the glens and the riparian floodplains in the western fringes of the Cairngorms National Park.

The conditions that gave us high densities of breeding waders across much of Scotland are long behind us now: in places like the Ochils, the Kilpatricks, Clyde Muirshiel, Strathallan, Strathardle and the Forest of Clunie waders were once abundant but are now either gone or barely hanging on; across swathes of lowland Scotland waders have more or less gone from an arc from the Central Belt through Strathmore and Aberdeenshire to Moray and Inverness-shire. Even the Rothiemurchus Forest once had Greenshank and Curlew breeding in clearings amongst the ancient Pines – of course these birds are long gone too, and each wader survey in Strathspey reports more declines. In Deeside, Donside and the Angus Glens we presumably have some breathing space before passing the tipping point, but forestry cover has increased and keepers work larger beats; the movement is only in one direction. Galloway is at the end of road - the remnant wader populations are nothing but a faint memory of the days when the gnarly hills quivered to the calls of Curlew - there's a smattering of pairs left here and there, the final death throes of what was an estimated 5,000 pairs not that long ago.

The list of successful examples of regional recovery of waders using the main policy instrument designed for this purpose – agri-environment wader management options - is precisely zero. So in each distinct landscape of mainland Scotland from Caithness to the Rhins of Galloway, there is effectively a tipping point beyond which the regional future of breeding waders looks bleak. The journey toward and beyond these tipping points in each region is both driven by a simple process but influenced by a suite of interactive factors which are challenging to unravel. A cursory glance at a the most recent BTO Breeding Bird Atlas map (which began 16 years ago now – we are due another one soon which would show this pattern even more starkly) shows Curlew and Lapwing concentrated around areas of grouse moor management. We know that waders are about four times more likely to raise a brood on land subject to effective predator control than in areas where there's no predator control. We also know that to maintain wader population stability, gamekeepering effort needs to increase with every additional block of forestry. Birds breeding in intensively predator managed areas produce a surplus of fledglings that sustain unproductive populations in nearby agricultural areas or areas of higher predation. But within a breeding wader landscape, when one estate turns to carbon credits, adds an additional block of forestry or gives up on grouse and moves to a released gamebird shoot, the challenge of managing for grouse on neighbouring estates and thus maintaining wader populations gets one notch more challenging, and we have no means of assessing the significance of each cumulative step that is taken towards a regional tipping point.

So what to actually do? Are we happy to have the future of our breeding waders wedded to the uncertain future grouse moor management faces in a changing climate, both meteorological and political? Are we ready to polish up our incubators and nest fences ready to work in post-grouse moor, post-tipping point landscapes? How would we feel if Curlew became scarce like Greenshank, a prized bird at the top at the top of a remote glen to be reported to the local bird recorder; Oystercatcher a bird of roundabouts and roofs; Lapwing a bird of electrified mammalian exclusion fences? Are we content to continue with the ineffective status quo of finely scattered wader conservation interventions across the landscape without any semblance of over-arching spatial strategy? Or are we going to stiffen our resolve and attempt to shift the direction of travel away from the approaching tipping points – and if so, are we going to attempt that everywhere, or in targeted landscapes where we might at least have a fighter’s chance? Will we satisfy ourselves with periodic trite statements about reversing wader declines that reveal a tenuous grasp of the scale of the processes that are driving those declines – or will we attempt to communicate honestly and openly about the scale of the challenges and what the realistic endpoints might be?

The purpose of writing this piece was to argue the case for some clever regional simulations or modelling to elucidate regional sink and source population dynamics and find out how we might avoid transgressing these tipping points. This wouldn’t be a futile endeavour - but perhaps it would also be wise to accept that all we ever seem to do is call for another piece of research, and frustrations with this state of affairs are not wholly misplaced - these are well-studied species, and the conditions in which waders flourish are well-known. We should also probably accept that there is scant evidence to support a hypothesis that one more piece of research will finally bestow upon policymakers the long-absent courage to put in place long-term, pragmatic, strategic policies to ensure the sustainability of our wader populations. It seems quite astonishing to say that even now, thirty years after we first started producing evidence on the factors driving wader declines, we have no meaningful framework or strategy, and very little consensus on what successful wader conservation looks like.

At a recent Curlew conference in King’s Lynn, organised by the excellent Curlew Action charity, groups from all over the UK and Western Europe presented their operational strategies for working in post-tipping point landscapes – where birds are still notionally present so hope cannot be relinquished, but there is no meaningful strategy for returning to a situation where birds breed sustainably absent targeted, labour-intensive human interventions: the rapid deployment of fences around nests and the rear and release of aviary hatched fledglings. No-one dared give much thought to how we might avoid the inexorable march past these tipping points: perhaps there is a growing sense in wader conservation that we are content to become a paradoxically life-affirming struggle to hold extinction at arm’s length.

If we have any greater ambition left, there is little time for ambiguity: the cumulative effects of the changes we’re seeing in the Scottish uplands are pushing wader populations closer towards those tipping points, beyond which it will be very challenging to maintain viable populations. If we are to find a meaningful future for breeding waders in Scotland, we must stake out space to talk openly and honestly about this process: the movement away from landscape-scale predator management and open landscapes is the driving force behind our breeding wader declines. We must also acknowledge that there is much support across many sectors for alternative land uses in the uplands; that there are many genuine benefits from more diverse upland habitats, land uses, and land ownership structures; that there are other important conservation objectives; that breeding waders will rarely be the uppermost consideration in the decision-making process. But all that notwithstanding, if we don’t find a way to secure the long-term delivery of the conditions needed to secure sustainable wader populations at least in some landscapes, those tipping points will be getting closer and closer.

David Jarrett is an ecologist at the University of Durham