Conserving species can be a complicated affair. Take this dilemma.
After being hunted to near extinction, numbers of a native predator are recovering and eating more of an endangered prey species, whose own numbers are declining as a result. Should conservationists accept that some successes mean losing other species, or reinstate lethal control of this predator in perpetuity?
Or perhaps there is a third option that involves new means of managing species in the face of new conditions. This issue is playing out globally, as land managers grapple with predators such as wolves and lynx reclaiming their historic ranges.
In the ancient Caledonian pine forests of Scotland there are fewer than 500 capercaillie remaining. This grouse is beset by multiple threats, not least shifts in spring weather caused by climate change that are driving its Europe-wide decline, relating to changes in when chicks are reared and available nutrition.
Additionally, and in common with other ground-nesting birds, capercaillie lose eggs and chicks to carnivores. As such, the recovery of the pine marten (a relative of weasels and otters) from its own near extinction in Scotland is contributing to the decline of capercaillie.
Internationally, little has been achieved to slow the heating of Earth’s climate, and decades of dedicated conservation efforts have not arrested the decline of capercaillie. Extinction will follow unless new solutions are found.
Killing pine martens, the capercaillie’s predators, might offer short-term relief, but it is socially and politically contested and scientific evidence on its effectiveness is meagre. Most importantly, it risks undermining the recovery of species conservationists have worked hard to restore. Instead, the challenge is to reduce the effects of predators, not their numbers, and encourage coexistence between species.
We have tried one such method in Scotland – with incredibly positive results.