So few and so skittish as to be invisible?

I’ve read in a couple of places recently some knocking of what’s described as a ‘safari park vision’ of visible big herbivores and their predators – a vision said to be espoused by Rewilding Europe. I’m not sure what the critics are saying, but I assume their contention is that, within Europe, large herbivore and predator populations will always remain at such low densities and be so skittish as to be basically invisible.

Predators, yep, but large herbivores?

Whilst I agree (and hope) that we’re never going to have Serengeti-style mass herds or migrations of megafauna across treeless plains in Europe, I don’t think we can say that we’ll never have impressive herds of European bison, visible in open habitats. My guess is that as numbers of bison build up at various re-introduction sites, they’ll become ever-more obvious, and, provided we avoid spooking them too much, they’ll be pretty relaxed having onlookers.

How about aurochs, or their anticipated ecological stand-ins, the Tauros? My guess is that the real aurochs formed herds too – I’ll go as far as to say obviously they did. And they’re more grazers than browsers so probably favoured more open regions. So, if the Tauros created by back-breeding really do exhibit the ecological traits of aurochs, I guess they’ll form herds that’ll venture into open habitats. Again, as long as they’re not hounded too much, they’ll probably be pretty visible.

Wild horses (or whatever ecological surrogates we come up with)? Their herding behaviour varies depending on the habitat, but they’re another grazer and will form visible herds in more open habitats.

Groups of cervids are quite happy to venture out from the woodland edge to nipple at low shrubby vegetation and will do so during the day in quieter areas.

If you put all this lot together, in protected areas with a mix of open and more wooded habitats, free from harassment by people, then surely they’ll remain pretty visible to discrete onlookers?

 

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How and where to induce land sparing

Evidence of the benefits or otherwise of land sparing – concentrating agriculture in the best and most versatile areas, and thereby leaving other land (and marine) areas aside for other uses – is growing.

Much of the evidence, where researchers use the model framework devised by Green et al. (2005)*, appears to favour land sparing, at least in frontier landscapes, where sensitive species associated with unconverted habitats persist. I’m not sure there’s much evidence either way for long-settled, cultural landscapes such as those across north-west Europe, and people using the Green model in such areas will need to be careful in how they select baseline habitats (I’ll come back to this).

If ecologists convince us that land spring is, indeed, a way forward, two practical questions confront the conservation and land use planning communities: Where to induce land sparing? and How to induce land sparing?

I’ll be discussing both the Where and How questions over the next few months.  Here are a couple of delivery mechanisms that I’ll expand upon in future posts:

Spatial planning: this is kind of obvious, really. Take the oil palm industry. Conservationists correctly continue to put a huge amount of effort into the Roundtable on Sustainable Palm Oil (RSPO) certification principles and standards. But I think we’ve neglected spatial planning, which is the responsibility of governments at various levels, and which could steer oil palm expansion (certified or otherwise) into already-converted lands. It’s no good if RSPO-certified growers only go for concessions in largely converted areas, whilst growers not intending to gain RSPO-certification go for and are issued concessions in unconverted areas. The NGO community could work with government land-use planners to initiate some sort of roundtable on biodiversity (and terrestrial carbon) friendly spatial planning. This ought to focus in the tropics where rapidly expanding tropical commodities are a major driver of biodiversity loss. What role might spatial planning play in, say, the UK, where land sparing is more about expanding habitats, rather than preventing further conversion and habitat loss? Well, in England, District councils prepare proposals maps – a detailed spatial plan of their areas showing where things like new homes will be built. These maps tend to ignore what goes on away from areas subject to built development, but could define habitat creation areas much more clearly. And in a future where production is being withdrawn from marginal farmland, do we really need to maintain such a dense highway network? Maybe we do, but we decommission other sorts of obsolete infrastructure – such as coal-fired power stations and old nuclear – so why continue to maintain a dense web of low-usage lanes? Converting some of these to green lanes with access only for cycling and walking could help to de-fragment landscapes and render recovery of bigger extirpated species more feasible. And spatial planning could work to identify the best parts of the highway network to decommission.

Land trusts: what to do with all this ‘spared’ land? Someone or something will have to be responsible for its upkeep. Conservation and community land trusts are an increasingly important means through which land is ‘spared’ from conversion and managed long term. They range from very local community groups convened to manage a particular site, to country-wide non-governmental organisations, such as the Jocotoco Foundation in Ecuador, created to establish networks of reserves protecting (sparing) habitat critical to the survival of endemic species. Then there are regional organisations set up to support the activities of these local land trusts, such as Nature & Culture International which is focused on the tropical Andes, and international organisations, such as the UK-based World Land Trust and the US-based Rainforest Trust and, of course, The Nature Conservancy, which support projects across the global tropics. Here in the UK, we of course have the National Trust, and reserve-network creating NGOs like the RSPB and county Wildlife Trusts. I suggest we need a big push in the UK to create a more acquisitive land trust culture. We need riverside land trusts that specialise in acquiring entire river corridors (if entire floodplain corridors were in the ownership of community trusts who’s activities weren’t compromised by flooding, we could relax about how the river channels themselves are managed); we need land trusts focused on creating big landscapes subject to full-on trophic rewilding (i.e. where extant and surrogate wild herbivore and carnivore communities are re-established); we need urban-fringe community land trusts focused on creating big natural open spaces for people.

References:

*Green, R.E., Cornell, S.J., Scharlemann, J.P.W. & Balmford, A. 2005. Farming and the fate of wild nature. Science 307: 550–555.   [At the time this paper was published, I was delivering advice to farmers on how to make their farms better for wildlife – and I absolutely hated the message being presented by Green et al. Now I see this as probably the most important paper in conservation science and land-use planning to appear in recent decades…… ]

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Wild cows

I’m a birder turned botanist turned ungulate enthusiast. Because I only recently discovered ungulates, I don’t know much about them. I can therefore make naive comments and pose some dumb questions.

I gather that we used to have aurochs in southern England. As humans first spread across landscapes, they extirpated wild cattle and replaced these with domestic stock. If you believe Vera, the landscapes the first humans encountered already contained a good portion of open habitat – that’s where the aurochs and other part-open-habitat specialists were hanging out – and our domestic grazers and browsers simple came to occupy the niches of these large wild herbivores. And we expanded the open grassy habitats a lot by clearing the forested parts of the landscape.

We’re now in a phase of agricultural consolidation and contraction. Today, as people withdraw livestock and arable farming from remoter regions, and in the absence of the wild herbivores we drove out, the part-open-habitats are closing in as woodland takes hold.

Now, as a rule, I’m not keen on the idea of trying to resurrect – de-extinct – lost species when there are species on the brink of extinction that could be saved and recovered with a bit more effort and resources. I’d rather we helped folks in Indonesia to get the Javan rhino numbers back up, and spread them out across a few more sites, than spend a lot more cash trying to bring back the aurochs. For now at least.

But I also think it would be great to have aurochs back. And I’m a realist. Realistically, there are bright science-types who say they can conduct selective breeding of extant domestic cattle and thereby get something that they assume will be pretty much like an aurochs in looks and ecological traits. And there are people with cash who’ll help fund their efforts.

For example, the Tauros Project in the Netherlands are actively attempting to breed aurochs-like cattle that they’re calling Tauros. Consequently, we’re likely to have available animals that are closer in their behaviour and functional ecology to aurochs than the hardy and rare breed cattle we actively select for conservation grazing projects.

Do we reject these proto-aurochs – Tauros – and continue to use hardy or rare cattle breeds instead?  For Tauros to perform in a way that’s behaviourally and functionally similar to extinct aurochs, they’d presumably need quite a lot of space. It’s no good doing what we do to rare breeds in conservation grazing schemes – hemming them in with fencing, supplying water troughs and feeding in winter. That sort of pampering extinguishes some of the behaviours and ecological benefits of these animals: cow pats are a critical resource for all sorts of bugs, for example, and many dung specialists are adapted to exploit this patchy, unpredictable resource distributed across large landscapes; same with carcasses; and presumably wild cattle performed important seed dispersal functions to which some plant species have adapted and which only really work if the cattle are wandering around big landscapes. Some people say that big herbivores would need a huge amount of space to allow for seasonal migrations. But I’m pretty sure that proto-aurochs could persist year-round in the relatively benign lowland English landscape without the need to perform large-scale movements.

Is there anywhere in southern England large enough, and with the right mix of wooded and open habitats, to support a viable population of Tauros without too much pampering and meddling? I have one or two sites in mind, and will come back to that…….

Is there anywhere down south large enough to also support their key predator – wolf presumably? I’d say, ‘no: not for a while, anyway – but give Brexit time’. For now, we’d need some degree of intervention to replicate the sort of predation pressure we might expect once fully comprehensive trophic rewilding has taken hold. Bright ungulate ecologists could construct simulation models to work out what sort of predation pressure might be roughly right. And we could do the predating – we could stand in for wolves.

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Densely-populated English lowlands?

A common factor cited as precluding large-scale rewilding in the English lowlands is human population density – the UK is a densely populated country, the lowlands of the south particularly so, and there’s thus simply no room to set land aside for wild nature.

That’s true if one lumps high-density urban areas – like London, the commuter suburbs and the south coast conurbations – into one’s calculation of mean human population density. But I wonder to what extent such urban data skew the picture for the countryside – i.e. the areas which might actually be rewilded to support large herbivores and their predators? How does our rural human population density compare to that of countries that have managed to retain at least some large mammals – India, Nepal, Cambodia? Maybe our rural areas are indeed much more densely settled.

A much more decisive problem to my mind would be the density of the highway network. How dense is the web of rural roads in areas with relatively low human population density?  And how do traffic volumes and speeds vary across this network?

Are there areas with low human population density, low road density, low traffic volumes and speeds, and low agricultural yields?

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Rewilding and targets

A frequent criticism made of those in favour of ‘rewilding’ is that they are unable to set conservation targets. If the system is driven by natural processes – if it’s natural, not human-controlled – how can ‘we’ know that the project is a ‘success’?

This seems to be a peculiarly British obsession, which has rubbed off to some extent on other countries through the CBD and its National Biodiversity Strategy and Action Plan requirements. The target-led obsession is displayed most starkly in the UK Biodiversity Action Plan process. Starting in the 90s with the publications of the Biodiversity Challenge Group, UK conservation adopted the idea that each and every habitat, and each and every species that was big enough and cuddly enough to be noticeable, or was in trouble, should have a Habitat Action Plan or a Species Action Plan for it, within which shall be set explicit targets for its area, population, range etc.

The UK BAP process consumed the better part of many careers and thankfully seems to have lost momentum. People got pissed off with so many meetings at which loads of bored souls were set the task of defining precisely how many hectares of CG1 grassland shall be created over the next five years in Purbeck. Or how many Bittern Units were required to ‘deliver’ a fixed number of bitterns in x years. Having gone through such torture, the various action plan groups were then set the task of reviewing all the targets, again and again.

The target-led approach sort of reflects the tight management of habitats and species that characterise UK conservation: most UK wildlife survives on farmland, and usually on patches of ‘old farmland’ spared from agricultural improvement but now in need of very tightly prescribed conservation management to maintain it as it was when the long vanished farming systems sustained it.

By necessity, a Habitat Action Plan for chalk grassland in Purbeck will contain prescriptive targets for maintaining the area of particular chalk grassland sub-communities. We are aiming to ‘lock’ these habitats and their constituent species in place and so to sustain the biodiversity that is assembled within these habitat patches.

This is absolutely right because if we get the management wrong, we run the risk of losing wildlife communities in the only patches of decent habitat remaining. Most terrestrial wildlife in the British lowlands is associated with old pre-industrial-farming systems.

But we also want to expand habitat, and perhaps less fortunate has been the habit of assuming that newly created habitat should take the form of such surviving ‘old farming’ patches – i.e. that we need targets to expand, say, CG1 chalk grassland specifically (rather than just open grassland on calcareous soils). Or hedgerows – we have targets for, and spend a huge amount of cash on, extending the length of old-farming style hedgerows.

Perhaps the most extreme (or explicit) example of this target-led approach in the UK is the task set for Natural England (NE) to maintain or restore Sites of Special Scientific Interest at or to ‘Favourable Condition’. To check that NE is delivering on its service-level agreement to government, it instigated Common Standards Monitoring – a process whereby very precise ‘attributes’ were identified for each distinctive habitat type found across the suite of SSSIs in England. So, you have attributes like percentage of bare ground, percentage cover of a given plant species, population size of a given bird species. And, with targets for these attributes set, each and every SSSI unit is monitored now and then.

These kinds of precise target setting exercises sort of work where, as I say, the aim is to ‘lock’ surviving patches of particular old farming habitats in place, with particular plant and animal communities.

Do we need such precise targets when we’re in ‘expansive’ mode – when we’re aiming to expand biodiversity beyond – outside of – old farmland habitat patches?

I’ve just returned from Colombia, where I looked at the efforts of a local conservation charity to secure patches of montane forest habitat critical to the survival of endemic species in areas undergoing active deforestation. Having purchase patches of habitat and added these to their expanding nature reserve network, these conservation charities don’t then set targets for intensive management. These organisations are also acquiring cleared areas between habitat patches. Here, they engage in assisted natural habitat regeneration: basically, they exclude livestock, foster any ‘volunteer’ shrub and tree seedlings that appear, and sometimes harvest seedlings of the less dispersive species from other areas and plant these. Other than that, they allow these areas to develop in their own way, including under the influence of seed dispersers, predators and herbivores . They’re not overly concerned about precisely how the habitat developed, what the population size of a given frog or nematode might be at a given date, etc.

Are the Colombians getting it wrong? And, if it’s right for them for adopt such a relaxed approach to biodiversity recovery, why not us?

I’d argue that it’s right a proper to have pretty explicit targets for the condition of SSSIs and other bits of surviving old farmland of high biodiversity value. I think it would be wrong to abandon tightly prescribed management of these sites – reckless in fact – other than where there’s a good case for doing so.

But I suggest we don’t need to be consumed by endless targets and infinite monitoring in new conservation landscapes – rewilding areas. If we must have targets, maybe ‘area’, i.e. to ‘rewild 5,000ha’, or a ‘target’ population density of a few influential beasts, say ‘roughly x deer per square km capable of supporting roughly x breeding female lynx across xx,000ha’. One could set and monitor such targets without endless target-setting and review meetings, thus freeing up staff time for actually delivering stuff.

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High-yielding, wildlife-friendly farming?

A negative relationship between the intensity of farming and the densities of birds breeding on farmland was found across Europe and reported here:

http://rspb.royalsocietypublishing.org/content/268/1462/25

In other words, bird populations tend to be lower in more intensive farmland.

This has been true in practice, to date, across Europe, but can the relationship be broken: is it possible to maintain high yields and increase the population densities of birds nesting on farmland? Can high-yield farming also be wildlife-friendly – or at least farmland bird friendly? Work by the RSPB at Hope Farm (a conventional ‘intensive’ farm at which the RSPB is testing the response by birds to various bird-friendly management techniques) suggests that bird populations can indeed be increased in intensive farmland. If this is generally true, can we have the best of all worlds: high-yield farmland, supporting good populations of farmland-associated wildlife, and land spared for species unable to persist without conflict on farmland?

 

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