To intervene, or not. A quandary that is increasingly tying knots in the minds of conservationists, ecologists and biologists as the rewilding movement continues to fire the imaginations of many towards a more nature-led approach. Within the UK's small, fragmented and fragile habitats, there is still the tendency to protect. With much time, money, dedication and - dare I say - ego invested, it can be hard to let go and let nature decide.
But with so much - possibly all - of the British countryside now modified in some way by human presence, it begs the question: once we have intervened, does that mean we are duty-bound to intervene again and again? After all, we have already meddled with natural processes - disrupting nature's own ancient rhythms. Is habitat now primarily the domain of the human over the animal; and if so, can this be reversed? Against the volatile backdrop of climate breakdown, the question of whether or not to intervene is a complex and nuanced one - context is king.
I was reminded of this recently when news of cattle egrets - new arrivals to the north Norfolk coast courtesy of climatic shifts - devouring the resident natterjack toads prompted a range of reactions. Some said management was the answer, others wanted nature to decide. Dilemmas such as this will soon become commonplace as climate breakdown shakes things up like never before, opening a Pandora's box full of novel species interactions. So, do we manage our way out of a human-induced situation, or sit back as 'survival of the fittest' plays out? At what point do we step back?
The cattle egrets reached our shores under their own steam: they were not part of a human-led introduction. Their prodigious range expansion across the world began in the early 20th century. They were a rare visitor to Britain decades ago and now breed here; becoming a more common sight in parts of eastern and southern England following winter influxes beginning in 2007. Likely triggered by a combination of drought conditions in the Mediterranean and increasingly milder winters here. Is there a conundrum in this case when natterjack toads are a widespread species - albeit declining in the UK? Should the toads be translocated to elsewhere in the region to save a local population. Do cattle egrets need to be culled or captured to save the toads?
There is a growing consensus that climate breakdown will create more simplified ecosystems that favour generalist species over the specialists. Species that can easily adapt and take advantage of a wide variety of food sources and habitats, without having to be reliant on a particular one for survival, stand to benefit enormously; while populations of more specialised species are likely to shrink with a more limited set of ecological interactions to fall back on. As generalist species proliferate, a less diverse environment could emerge - with trophic and structural complexity taking a hit.
But if species diversity is to diminish, what about what's left? The generalist species then exert a greater effect on each other. As some links in the ecological chain are broken, new ones will be formed or become more influential - setting off new ripples of their own. As less land becomes habitable, pressure grows on prey supplies. Could this lead to some generalists becoming specialists?
At a time when we are trying to take a step back, the increasing intensity of climate volatility is making that urge to intervene all the more tempting. But create more space - and options - for nature, and you reduce the need to intervene. With everything being squeezed like never before, we need to alleviate some of that pressure.
As the negative aspects of a more unpredictable climate full of extremes magnify the ecological voids in ecosystems around the world, with species ill-equipped to adapt to the presence of new arrivals or shrinking habitat, the need to deliver more space for nature heightens. The healthiest ecosystems are whole, connected and fully functioning at every trophic level. To avoid intervention, we need this space, wholeness and connectivity to return. Maybe then, we can leave the egrets and toads to it.
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