Saturday, 14 November 2015

Murmuration


It’s 4 pm on a dull November evening. The sun has already set and now the sky is the uniform, metallic grey colour of zinc. I’m standing on the boardwalk in our meadow, hoping to watch the starlings gather but nothing is happening. Perhaps they won’t come? Maybe they are roosting somewhere else?

A tight flock of finches flies directly over my head and lands in a weeping willow. Goldfinches? No, linnets. (Why do we never see them in the daytime?) Other flocks drift over; jackdaws, rooks, gulls, even redwings, but no starlings. I’m getting cold and bored and I have more important things to do than… but, "Hold on a minute: Starlings!" A flock of about twenty birds circles, splits and reforms above the grazing cows. It’s not exactly a murmuration, but their aerial antics attract another group and the flock builds to several hundred birds.

By now the light has started to fall off to the point where my camera is useless, but I’m keen to see the ballet play-out to the end. Where will they actually roost? To my dismay they fly off north towards Washout Pit but a second group is assembling and swooping low over the reeds on the far side of Cloudy Pit. Just as they dive into their roost another flock forms and then splits in two with half peeling away and half staying. As groups assemble they form a vortex of birds that sweeps around the amphitheater created by the meadow banks and the lakeside willows. The flock stretches out into a parade and then bunches up to execute a tight turn. I hear the wind rushing through millions of primary feathers as they form a river of birds that approaches me from behind and then I am drowned in birds, like a boulder in a riverbed with the torrent bulging over me. A sparrow hawk glides casually between the trees and almost gets into the flock before he his noticed, then the starlings react by bunching up into a tight ball. It’s like a muscle spasm. 

It seems that our meadow is the gathering point for birds from several roosts including the Hayling reed-bed, Washout Pit and Cloudy Pit and, so far, the numbers are in the low thousands.

Where do the birds that roost here in winter come from? British starlings might join us from the big cities or from a more scattered rural population, but continental starlings outnumber them by the million so that a single murmuration might hold 100,000 birds. 

I remember being told that you could guess at the origin of a starling from its songs and calls. They love to imitate other birds, people and even machines. If you hear a starling imitating a curlew, then it must be a rural bird and if it imitates a golden oriole or a bee-eater, it's probably not from around here! We now have starlings that imitate buzzards and we used to have a song-thrush that imitated the reversing buzzer of the big tippers at the quarry.

Scientists first learned the scale of the autumn influx of starlings when the War Office used radar to monitor air traffic over the North  Sea and English Channel during WW2. Soon after sunset their screens would fill with clouds of "Angels" which they found hard to explain until they spotted the birds in searchlight beams and as they flew across the face of the moon.

The Paxton starlings only spend half the winter with us. I have no idea where they go in January. How do they choose where to roost? The Royal Society for the Protection of Birds' website tells us; "They roost in places that are sheltered from harsh weather and predators, such as woodlands, but reedbeds, cliffs, buildings and industrial structures are also used. During the day, however, they form daytime roosts at exposed places such as treetops, where the birds have good all-round visibility.” This flexibility over where to roost could be a factor in the way starlings have managed to flourish across the globe, far from their native range.

Most research on starlings has been conducted by agencies that want to find out of how to get rid of them because, where they have been introduced in America, New Zealand, South Africa and Australia, their populations have soared. Over here in the UK there's a different story. Our starling population has fallen by over 80% since 1979. In the last ten years we have lost over 30% of them, meaning they are now on the critical list of UK birds most at risk, not because they are rare, but because of the alarming and rapid decline in numbers. The decline in our (UK) breeding population is believed to be due to the loss of permanent pasture, increased use of farm chemicals and a shortage of food and nesting sites in many parts of the UK. It’s the same in Europe, so there are far less continental starlings coming to visit us in winter than in the ‘80s and ‘90s. Given this decline in the overall population, it is not surprising that many traditional winter roosts have disappeared altogether. I just hope ours is not one of them!

If all this makes you want to grab your camera and head out at dawn to capture the birds leaving again, think twice and don't bother. The birds leave a few at a time as they wake up. Some of them are still half asleep and groggy so head-on collisions are quite common in the mornings. They almost never happen at dusk.