Bird count adds to nature watching entertainment

THERE is an old joke when it comes to assessing numbers of wading birds in vast congregations that pose a headache for those engaged in population surveys.

Simply count the legs and divide by two.

When it comes to something as mobile as birds, tallying totals is far from easy.

And if they won’t keep still, how do you know you haven’t recorded the same individual twice?

This weekend, people across the UK are being asked to tot up birds in their back gardens. If you have never taken part in the Big Garden Birdwatch then it is well worth a go – if only to take time out from the mobile, computer and TV screens or various chores and simply sit and watch nature on your doorstep.

Although the numbers won’t be on the scale of great flocks of estuary birds or swirling murmurations of starlings, there is a straightforward, if rough and ready, method of counting to make sure you get your ducks in a row, as it were.

In short, you count the maximum number of a species seen at one time, rather than adding them together in a running total as you go along. So if you spot two chaffinches at the bird feeder, a bit later one on its own, then later three visiting at once, you record three as the maximum total – as you can be sure you haven’t double-counted those three seen together. Hopefully that makes sense!

Taking part, one can be surprised by the variety and number of birds visiting one’s back garden – especially if you regularly feed them, which is why the RSPB holds its Big Garden Birdwatch survey at this time of year. And the ‘citizen science’ survey, run annually since 1979, is invaluable in shedding light on the changing fortunes of our most common feathered friends.

Some widespread species have declined in number – including the song thrush – while others have fared better over the years and become garden regulars, including the long-tailed tit and siskin.

Last January nearly half a million people took part in the annual citizen science survey, counting almost eight million birds, and the top ten species recorded were the house sparrow, starling, blue tit, woodpigeon, blackbird, goldfinch, great tit, robin, longtailed tit and magpie.

Other common garden visitors and inhabitants include the coal tit, nuthatch, collared dove, wren, chaffinch, greenfinch, jackdaw, carrion crow and dunnock. But there are plenty of other birds that may pay a flying visit.

Given lockdown restrictions limit what one can do at the weekend, why not visit the RSPB website and take part in surveying garden species. Our birdlife is counting on you.