Goats in the Burren National Park

In a recent publication http://www.nature.com/embor/journal/v9/n1s/full/embor200877.html http://www.nature.com/embor/journal/v9/n1s/full/embor200877.html
Ilkka Hanksi reminds us that our species is adapted to short term and small scale thinking and doing. Our sense of time is up to decades rather than centuries, and our landscapes are tens rather than hundreds of square kilometres in extent. Hanski argues, persuasively, that this is why we do not see the urgency to cut carbon emissions, prepare for peak oil, scale up our management units for greater sustainability or let historical changes inform our management. Basically we find it difficult to manage for change, especially change over decades and longer.

The MP would benefit from a debate on what is significant about the Park now and what it might be significant for in the future. Some of the significant features are well known (flower-rich limestone grassland; karst landscape; ancient monuments; turloughs; the booleying system) but here are a few others:

The Burren must be one of the most sensitive sites in Europe to climate change given its mixture of glacial refuge and Lusitanican plant species. How long will Dryas persist and, if it does so, does Burren Dryas hold genetic secrets that signal adaptation to CC, and can this inform the fate of other more boreal populations? Can the plan's objectives of management be climate change proofed?

Hazel scrub: How significant is this in terms of extent and quality at the Irish and European scale? Is it dominated by hazel because the more sensitive species have been eaten out? Is it a (species poor) example of calcicolous scrub?

How significant was use of the woody vegetation by people?

How significant was grazing and browsing by flocks of managed goats in the summer/year round in terms of the quantity of scrub and the quality of the grasslands?

The Burren (and possibly around Lough Corrib) is one of the few places in Europe where a domesticated large herbivore (the goat) is still going feral - as it has been doing since the Bronze Age. The "wild goat" of Crete - a Red Listed speceis - is an anciently feral domesticate and no less interesting or significant than the true wild goat for that. Is this significant?

The feral goats in the Burren

There have been goats in what is now County Clare for millennia, and they will have been escaping to high and dry rocky ground and forming feral populations since they were first introduced to Ireland. The vegetation of north-west Europe is, like the Mediterranean vegetation, adapted to being grazed and browsed fighting back chemically and physically or escaping being badly damaged by keeping out of harm's way.

When goats attack tree and scrub species they select some (% attacked above its % availability) and avoid others (attacked proportionately less than % availability). So, in the generalised spectrum from selection through to avoidance for free ranging goats at free ranging densities (of less than 20 goats per sq km over their whole range) on calcareous substrates:

Goats select for barkstripping and browsing: Sorbus spp, Viburnum spp, Salix spp, Taxus, Ilex and tend to avoid Corylus, Alnus, Quercus, Crataegus, Betula. Fraxinus and Prunus are neither selected nor avoided.

Of course, if you corall goats at much higher densities they will demolish what for them is less palatable woody vegetation. For example, we removed high density birch saplings and coppice regrowth from a sand dune habitat by fencing in feral goats at the equivalent of 100 - 200 per km sq over three summer seasons. I have no doubt that one could do the same with coppice regrowth of hazel. This method of controlling scrub is, in terms of capital and operating costs, expensive but could be combined with manual and chemical control to restore flower-rich grassland.

The free - ranging feral goats in the Burren are, thus, most unlikely to exert much control on the hazel scrub. In the two permanent exclosures on Mullach Mor there is a higher density of scrub than outside but we cannot tease apart the effect of lack of cattle and goats, the sheltering effect and the random effects of the sample size of two. Goats may, however, over millennia - and certainly over the last century when there would seem to have been more and more feral as opposed to managed goats in the Burren - have profoundly altered the composition of the hazel scrub. Would there be proportionately and absolutely more Taxus, Frangula, Rhamnus, Salix, Sorbus hibernica if the goats had not selectively attacked at least some of these species?

So, if there were no feral goats in the Burren, perhaps do not expect the hazel scrub to increase in extent - the goats probably have little effect on this aspect of its ecology - but this may in time allow the hazel scrub to become more species-rich in terms of woody species.

If the feral goats in the Burren are, however, to remain, what it is about this population that is so significant that they must be conserved? People enjoy seeing them? Culturally/historically important? Could one argue successfully that they help deliver desired and (internationally)significant vegetation?

(Gordon Luikart and his colleagues found that the genetic diversity of goats across Europe is high. It looks like goats have managed to retain much of their genetic diversity despite being domesticated. This is why on genetic grounds it has been difficult to argue for genetically pure strains of ancient ferals etc - and this would not apply to the Burren for the reason outline above. It also helps to explain why feral goats are so successful (compared with feral sheep)).

If the Burren farmers get fed up with goats breaking down wall again or a livestock disease breaks out that they harbour would removing all the goats be acceptable? Q fever affects small ruminants and some people succumb to the infection and die. Portugal decimated its domesticated goats some years ago in response to a Q fever outbreak. If the outbreak currently affecting 1000s of goats (and sheep) and killing a few people in The Netherlands gets to County Clare and the RoI decides, like Portugal, to cull the Burren's goats would this give rise to a decline in the condition of its internationally important features?

Back to climate change and what the Burren will look like by the end of the century. Taking a Moderate GHG emissions scenario (nothing less than this likely after the Copenhagen summit) , the Burren will be hotter and drier in the summer (and more fire prone) and wetter in the winter - more Mediterranean.

Maquis, matorral, dehesa, montado and so on are all goatscapes with (often) tightly cropped flower-rich swards and many of the forbs and scrub species are noxious and/or spiny. Large trees such as holm oak and cork oak, used for their timber, firewood, cork, acorns for pigs, dominate some of these landscapes. The way goats are used to make milk, meat and skins in these biomes is through shepherding, sometimes folding the animals at night to harvest the dung and protect them from large carnivores. In a sustainable development model for the Burren is there an economic return/societal benefit/evnviromental benefit from shepherded flocks of goats (and no ferals)? I can see no reason why these should conflict with winter grazing by cattle. Indeed, by shepherds targeting where goats attack plants, they could bust through impenetrable scrub to allow beasts access to islands of grasslands.

This is going to sound a bit crazy, but fire will become an increasing issue in dry karst landscapes, especially where the volume of inflammable scrub increases in the absence of grazing and bbrowsing.

Back to Hanksi's paper: Can we think far enough and big enough ahead for whatever objectives are set within the MP to allow for flexibility, management for (climate) change and new paradigms such as Mediterranean style shepherding? If not, it may be very difficult retaining the Burren's feral goats on the grounds that they conflict with other interests of greater significance.