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| From Summer to Autumn |
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Page 1 of 6 Jean Lawman describes some seasonal changes in the natural world. A field of half ripe barley, wind-whipped and green gold in the evening sun, stretched to the horizon like a rippled sea. Normally, such a field of conventionally grown barley holds little interest for the naturalist, but here, over the bent, softly feathered heads, now fattening with seed, slipped a squadron of dark scimitar bodies, here and there flashing pale burnished brown in the strong light. Described as black or dark brown in most literature, colour is not finite; it depends on angle of sun, colour of background etc., as any wildlife artist knows. .jpg) Common Knapweed. Picture by David Chapman. The speed of the birds was such that your eye could barely follow them; they flew into the wind, not with it, as you might think, before climbing and sweeping right round and down again to follow the same rough path. They left an impression of lines, a tracery of neatly executed curves, steeply rising contours and tight loops, dark on light – the flight paths of individuals. The Swifts were down. Sometime a bird stalled on a turn above, allowing moments when I thought it possible to see individual wing feathers slide over one another, altering wing shape and thereby enabling the bird to perform another seemingly impossible manoeuvre. This subtle mechanism, perfect after millions of years of evolutionary trial and error, is the subject of recent research for possible use in aircraft technology. The mind boggles! I never convinced myself that I saw it, of course I didn’t, it was happening too fast, although one thing was certain, they made much use of their tails; these changed shape quickly and often during the flight: they were pointed, broadly wedged or deeply forked. Tiny feet, long curved wings and a streamlined shape mean they are superb aerodynamically, and can glide for long periods using little energy. |
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