With its extremely effective mottled brown colouring, the little Eurasian treecreeper (Certhia familiaris) can look very like a mouse as it creeps up a tree trunk searching for food, hence one of its common names, tree mouse. That’s if you can see the treecreeper at all. It’s so well camouflaged that it’s almost impossible to see when stationary, and you need to focus really hard on a tree trunk to notice its scuttling creep upwards in search of the tiny beetles, earwigs and woodlice that inhabit the crevices in a tree’s bark.
The treecreeper has particularly large and sharp arched claws, which help it scale trees with ease, and its tail is stiff, which helps provide support when climbing. You will never see a treecreeper moving down a tree – it spirals its way to the top then flies down to the base of the next tree to start its climb all over again. And this feeding routine is almost constant – in fact, it’s so active that it’s been estimated treecreepers can climb as much as 2500 metres in a single day. That’s quite a feat for a bird that’s only 13cms in length. Its common name should really be mountain climber!