When my husband calls me to the window, I can’t work out what it is about the motionless dark brown object on the lawn that has attracted his attention. It’s only partly visible among the blades of grass and seems to be about the size of an unshelled walnut.
I’m about to ask when the shrew, for that is what it turns out to be, bursts into action. It makes a swift-footed bustling sprint of a metre or so and then comes to an abrupt halt, snout down in the short grass, posterior raised in the air, as it seizes whatever prey it has found.
The tiny creature is a pygmy shrew, Britain’s smallest mammal, weighing in at something between 2.4g and 6g … and hunting is its main priority. Its incredibly low body mass results in a high metabolic rate, and to survive it must feed day and night, eating up to 125% of its body weight every 24 hours.
Though these diminutive hunters often move about along surface tunnels through vegetation, this individual seems happy enough out in the open. It makes the occasional foray into what would seem to be the safer territory of the herbaceous border, disappearing from view for a few seconds and then re-emerging to resume a rapid criss-crossing of the lawn in an endless search for the insects, arachnids and woodlice that make up its diet.
Far from being the perfect suburban sward, the grass is interspersed with thyme, clover and patches of eyebright now long past their summer best. The shrew happily and profitably explores them all. Only the patches of yellow-green moss cause it any unease; these it races across at an even higher speed than usual, as if there were a sense of increased vulnerability when traversing the lighter coloured growth.
Just as we’re pondering how much energy an avian predator, the shrew’s main enemy, would be prepared to expend in return for such a small mouthful, a kestrel sails over the garden. But the bird fails to spot the shrew, or has perhaps already sighted potentially less fortunate prey, and comes to a hover above the neighbouring field.
