Tackling the invaders

What do buddleia, rhododendron, stoats, grey squirrels and snowberry have in common? They are all beautiful and fascinating species of animals and plants that can wreak havoc on other local wildlife if they turn up in the wrong place. Then they’re called invasive non-native species (INNS), and they’re just a few of the 3000 or so that we now have in the UK. In the wrong place they’ll have no natural predators or diseases to keep them in check, so they start to take over, shading out local plants, like rhododendron does; eating ground-nesting birds, like stoats can do on islands; or passing on fatal diseases that they’re immune to, like grey squirrels have done to our own native red squirrels.

And climate change may be making things worse – with new weather patterns they haven’t evolved to withstand weakening the ability of our native wildlife to fight off stronger invaders. This can create a vicious circle where INNS gain a foothold and make it even harder for local species to fight back. These invaders are successful because they are generalists – which means they do well in a range of different habitats – whereas many of our most cherished native species need particular conditions to thrive.

We have a lot of INNS in the green spaces around the town, which Cumbernauld Living Landscape, with the help of our Nature Ninja volunteers, is working hard to control. Species like rhododendron, snowberry, Himalayan balsam, dogwood, Japanese knotweed and giant hogweed all smother our native wildflowers and trees. And in doing so they don’t just squeeze out those plants, but the wildlife further up the food chain that depends on them.

But we have some natural allies too. Pine martens are spreading into the area again. Research is showing that these slinky, conker brown and cream native predators – bigger relatives of stoats and weasels – find it much easier to catch grey than red squirrels. In places where pine martens return the greys decline and the reds increase. We think it’s because the reds evolved at the same time and in the same places as the pine martens, so know how to escape them – the greys don’t.

If you want to know what you can do to help protect our local wildlife from these invaders you can visit Cumberauld Living Landscape’s Tackling the Invaders project page at https://cumbernauldlivinglandscape.org.uk/project/tackling-the-invaders/ . Keep a look out for updates too – we are planning more work in the future to try to tackle this problem.