What's a mesopredator? When I first heard the word, I thought it referred to something prehistoric, maybe T Rex's baby brother. But no, it turns out to be a predator that's not quite at the top of the food chain. Right at the top you have the apex predators such as wolves, bears, tigers and the like. Below them come the mesopredators - feral cats, mink, maybe even... buzzards?
I've been reading a fascinating paper published in the journal Bioscience. It's called The Rise of the Mesopredator. You can download the pdf here, but there's a summary of the main points here.
The basic message is you mess with predators at your peril. Things aren't as simple as that neat pyramid they used to teach at school: predators eat herbivores eat grass.
Sometimes big predators eat smaller predators; there are omnivores that cross boundaries; animals adapt to a shortage of one prey species by eating another; and so on. Which will come as no surprise to most readers of this blog, of course: shooters and keepers see this sort of thing every day.
One of the paper's main points is that apex predators keep the numbers of smaller predators (mesopredators) in check. And when humans remove an apex predator - as they do, because wolves kill livestock etc - then the mesopredators run out of control, and they don't neatly limit their own numbers to suit the availability of prey.
This has a disastrous effect on all kinds of species further down the chain - things like songbirds, for instance.
Fascinating stuff, and perhaps a good argument for reintroducing sea eagles, wolves and bears to Scotland if you're that way inclined. (Incidentally it looks as if Alladale may have shelved its plans to reintroduce wolves).
Or another way of looking at it... Having cleared out the apex predators from the UK years ago, humans have been battling to control mesopredators ever since. When a mesopredator's numbers spiral out of control, it's important to take action to protect biodiversity. Not pass ever stricter laws to make the mesopredator untouchable. Er, buzzards anyone? Badgers?
And yes, I know this will rattle a few cages. But is there any real science to show the effect of buzzard numbers on biodiversity? I suspect that's one research project the RSPB won't be funding.