3 minute read
Wildlife Chris Sperring MBE
Meet the “mouse bird”
THIS month’s article comes with a challenge: before the whole woodland erupts into the spring frenzy of birdsong there is a chance to test your peripheral eyesight and your ability to pick up soft, high-pitched sounds.
With the trees still leafless on your next woodland walk, take some time to stop, look around and listen for a specific sound. You will need to do this when other birds are not at their loudest, as the bird I am challenging you to find has a particularly faint contact call, comprising of three-five high-pitched notes grouped together, ending slower than they started. Keep your eyes peeled too, but not so much at the branches as the trunks of the trees.
As you listen you will perhaps hear many different species making sounds, but your target takes time to tune into and identification is much easier if you also get to see the bird that’s making that sound.
You are looking for a sudden, jerky movement moving up the trunk of a tree. At first you may well think it was just a trick of the light, but focusing on the moving object may just reveal one of our smallest and most inconspicuous birds. Your first impression may be that it’s actually a mouse, but closer inspection will show this neat little bird in all its superbly camouflaged glory.
You will hopefully be watching the amazing treecreeper. Measuring just 12cm long and weighing as little as 12gms this is the only member of the treecreeper family we have in the UK. Its general plumage is light speckled brown on the upper parts giving way to a creamy-white underside from neck to tail. If you’re close enough, or have good binoculars, you will be able to observe the distinctive down-curved beak, which it uses to probe insects and spiders from beneath tree bark.
They don’t sit still for long but watching them is quite captivating. They flutter erratically, almost butterfly-like, from one tree to the next, always landing near the base and making their way in short dashes up the trunk, listening and probing the bark as they go.
As they make their way up the tree they encounter branches, which they may also inspect, often shuffling along the underside, completely upside-down. Like woodpeckers, they have a stiffened tail, which they use as a prop behind them as they walk up the vertical tree trunks, and wide splayed toes to grip the bark.
Though this is an easily overlooked little bird, it is one of our great woodland characters and is probably more numerous than most people realise. Treecreepers are solitary; however, during cold snaps they often come together in large groups at night for warmth. I have heard tales of more than 20 huddled together in a blue tit box on a particularly cold night; a sight I have never seen myself.
In South West England breeding takes place between March and June and in our region they can rear two broods in a season. Natural nest sites include cracks or holes in trees and crevices created by flaking bark. The special nesting box designed for them
By CHRIS SPERRING MBE
mimics flaking bark and consists of a narrow, downward pointing triangular box.
Treecreepers are mostly found in deciduous woods, but they also like coniferous forests and one introduced species of tree has become a particular favourite for nesting in; the Giant Sequoia (redwood tree) because of the nature of its bark and the crevices it creates.
They are prone to nest predation, however, and those in small pockets of woodland, or near the woodland edge are most at risk from being discovered by their two main predators, woodpeckers and squirrels. Even if they do survive to fledge they are quite short-lived, averaging about two years, although the oldest was recorded at seven years.
Do take up my challenging and let me know how you get on. If you have not encountered this bird before it’s quite a test, but February is a great time to find them before they disappear into the background of spring growth and bird song. l If anyone is interested in learning bird song identification, I’m hoping to start a course at the Community Farm near Chew Valley Lake. Please follow my Facebook pages to find out when this will be starting.
