Teme Valley Musings, February 2019

by Stephanie Mocroft

In December, the Teme Valley Wildlife Group visited a National Nature Reserve in Staffordshire to see a natural phenomenon known as a starling murmuration. The site, along with Ham Wall on the Somerset levels and the pier at Aberystwyth, regularly sees huge sun-down gatherings of wheeling and chattering starlings. The birds fly in tight formation like dark, rotating clouds, and their displays can last for up to an hour. This intriguing starling behaviour begins in late autumn and continues until early March. A heavy snow-fall halted our plans to view a murmuration last December, so this year, even though light rain was falling, we were pleased to set off safely from Tenbury, reaching our destination, Aqualate Mere, well before dusk. This shallow lake of ancient glacial origin is one of the landscape features known as “the meres and mosses” that are scattered across the north-midland counties of Staffordshire, Cheshire and Shropshire. These unique watery relics of ice-age geology are quite different from any landscape familiar to us in and around our own Teme valley.

Aqualate Mere is only 3ft deep but, covering 70 hectares, it makes a significant body of water. It is fringed by reeds and from November onwards vast numbers of starlings come to roost in the reeds overnight. As the afternoon light starts to fade, flocks of birds arrive at the water’s edge and swirl in extraordinary flight patterns before dropping suddenly, in an orchestrated plummet, down into the reeds. Many thousands of birds fly in flocks of close formation, twisting and turning, dividing and regrouping, silhouetting against the sunset sky, creating an unforgettable display. Although drenched by a prior heavy shower, we onlookers “oohed and aahed” at the spectacle. It was reminiscent of a Bonfire Night firework display, our necks were stretched into the darkening sky, waiting for the next wonder to appear.

Why do as many as a million birds gather together in this way? No-one really knows, although suggestions have been put forward. When constantly changing direction in a tight group the birds can evade aerial predators. A sparrowhawk for instance, would find it difficult to concentrate on a single bird out of the swirling mass. Flocking also allows the sharing of information about the location of scarce winter food and roost resources. In the cool winter evenings, flocking closely together allows temperature loss from individual birds to be minimised. And finally there’s the old adage of safety in numbers. Regardless of the true reason, a starling mumuration is one of nature’s spectacles, and one that I’m very glad to have seen.