Country diary: I looked into the eyes of Britain's most savage killer

If I asked you to name Britain’s most savage wildlife killer, you might say fox or peregrine or goshawk, or perhaps even the golden eagle or the Scottish wildcat if you knew about such exciting rarities. But I think you would be wrong. Savage and killers they all are, no question, but in my book none comes close to the smallest UK mustelid, the weasel, Mustela nivalis, so tiny that its skull can pass through a wedding ring.

A few days ago I watched one hunting. It vanished into a rockery and emerged a few seconds later with a vole dangling from its jaws. Voles, rats and mice, as well as small birds, are a weasel’s staple, but a male will take much larger prey such as a full-grown rabbit, up to 25 times its own weight, kill it, and, incredibly, drag it away into cover. No other British predator does that.

Weasels kill by crunching their tin-tack canines into the base of the prey’s skull and not letting go. I have seen a wood mouse, rigid with terror, give itself up at the sight of a weasel. A second later it was dead.

There is a dry-stone wall at the back of our wood. I call it a weasel cathedral. Its galleries and internal boulder halls are perfect weasel dens and, apparently, also irresistible to mice, which doesn’t say much for mouse intelligence – the sheep sheltering in the wolf’s den.

While repairing the wall in April last year I came across a beautiful nest the size of a cantaloupe melon, carefully lined with sheep’s wool, feathers and mouse fur. The unmistakable musky scent of weasel told me it was recently occupied – probably a bitch about to give birth. Desiccated shreds of mice littered the interstices of that wall in both directions. I carefully rebuilt the wall around it.

I once caught a weasel in a Longworth box trap. Expecting a field vole or a wood mouse, I got a shock when I emptied it into a polythene bag. As I released it, it fixed me with a stare I have never forgotten. I felt I was lucky to survive.