Our countryside is fragmented and populations of many species are confined to widely separated islands. A Government announcement this week confirms that restoring and creating habitat in corridors, so that life can move between the islands, is a national priority. Let’s now hope the civil servants have the resources and vim to start joining the dots and creating a more healthy future for wildlife.
In May 2010 when David Cameron, Nick Clegg and their henchmen thrashed out the coalition agreement they committed the shiny new government to “introduce measures to protect wildlife and promote green spaces and wildlife corridors in order to halt the loss of habitats and restore biodiversity.”
Four years later with only 1.2 years left of this Government the wildlife corridors have yet to emerge. Yes there has been a very small amount of funding for Nature Improvement Areas, of which there are 12 around England, but these are chunks of landscape rather than corridors.
Reassuringly this week Farming Minister George Eustice announced that from 2016 there will be a new approach to making agri-environment payments to farmers. The new environmental land management scheme (which everyone is calling NELMS despite Natural England tweeting that this is not going to be its name) will make use of 12% of the £400 paid each year by every household to support farmers and landowners. In the minister’s own words “The new scheme will prioritise promoting biodiversity and will be tailored to fit local needs. It will be more targeted so we can deliver wildlife corridors but there will also be grants available to all farmers.”
So why are wildlife corridors considered such an important priority by our political leaders?
Over much of the UK wildlife has been extirpated from the countryside by intensive agriculture and development. Amazing, rich habitats that are home to particular endangered species, such as ancient woods, flower-rich meadows and heathlands are now fragmented – small chunks, often far apart. This creates big problems for wildlife and particularly for small animals.
Imagine living in a poverty ridden town, you want to move somewhere where there are better opportunities and a higher standard of living, but no-one has left your town in living memory and there are no roads, railways, paths or even maps. It’s up to you to take a chance, to strike out across the fields, woods and marshes in the hope that you will find a better place to live. If you are successful and return to the town next year well fed and finely dressed then it is likely that others will also try the same strategy, if you disappear never to be heard of again other towns folk will be less likely to attempt the same venture.
This is exactly comparable to what happens to fragmented populations of other species. If a butterfly leaves a suitable habitat patch and finds another, perhaps uninhabited, suitable place to live it may thrive and its offspring may try the same tactic. If on the other-hand the butterfly dies before if finds a suitable breeding home then its adventurous genes go with it.
In practice this meant that when the habitat of the Swallowtail butterfly in the Fens shrank so did the butterfly’s glorious yellow and black wings. Strong flying offspring tended to stray into vast acres of unsuitable agricultural fields where they died, while less mobile brethren eked out a living clinging to the last fragments of Milk parsley containing fen habitats – the net effect after many generations was a population of weak-muscled, short-winged, unadventurous butterflies that were very vulnerable to local change, and indeed they ultimately went extinct in the Fens. 
As habitats become fragmented successful travel between them becomes increasingly improbable. In addition the animals on the fragments are subject to occasional local extinction events caused by, for instance, flooding, fire, over-grazing or disease. There comes a point, which is different for each species, where the rate of local extinction on fragments falls below the rate of local recolonisation. This is the point where more populations are lost than created and a serious slide towards extinction starts.
Corridors are therefore important because they provide the linkage between the remaining habitat fragments enabling species not only to recolonize sites where they have suffered local extinction, but also to respond to changing environmental conditions and climate by finding new suitable habitat and extending their range. Without corridors long term changes that make their habitat too wet, too hot or uninhabitable in other ways will compress the zone of the UK where the animal lives.
So what should the civil servants do to realise the Government’s corridor ambition?
The Government press release on the new agri-environment scheme includes no further detail on how these corridors will be developed, so what are the dos and don’ts?
Dos
1) Think big – for instance while wildflower borders along arable fields provide short term benefits in terms of and pollen and nectar for bumblebees, they are polluted, cut, and ploughed so do not provide a refuge or sanctuary for most species – whole meadows of wildflowers provide a much richer habitat, a long term home to a wider range of plants and animals.
2) Think broad – anaemic threads of hedgerow are of use as guidelines for dispersing insects but are not suitable places for most species to breed or raise a new generation.
3) Link corridors to people and existing features – create and restore habitat along national trails, the coast and rivers where possible.
4) Use B-Lines as a template – B-Lines have already been mapped across several counties with Natural England and the Local Authorities – they provide a network into which wildflower restoration can take place
5) Use the Wetland Vision as a template – although the Wetland Vision has gone quiet recently – this is surely a chance to reinvigorate the corridor elements of the plan
Don’ts
1) Do not invest large amounts of public money in reinventing the wheel – look for existing schemes and proposals that fit the bill – scientifically under-pinned and already involving local people.
2) Do not expect corridors to create themselves – there will need to be targeting of funds into lines by local agency officers.
3) Do not worry if the corridor has gaps in it – the science clearly shows that areas of flower-rich grassland targeted into broad linear strips will provide essential stepping stones for many species long before the corridor is completely filled
4) Do not ignore other habitats – having lost 98% of wildflower meadows, restoring and recreating this habitat is clearly the highest priority that will get the biggest biodiversity bang for the buck – however heathlands, woodlands and perhaps other habitats should have their own corridor plans in due course.
There is a current appetite for creating a countryside that is more resilient to the effects of extreme weather. Corridors of wildlife rich flood meadows and wildflower grassland are part of the solution that will stabilise our soils, reduce the cost of floods and provide a more beautiful and enjoyable countryside for future generations.
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