Bird’s plumage
Over the last three weeks I have been watching a regular visitor to our seed-feeder, a male siskin. These neat little olive and yellow finches used to be winter visitors to our area, flying north to breed. They were definitely birds of the countryside, but if you walked along the Washburn Valley or through Timble Ings, you could be pretty sure to come across a flock of siskins feeding among the alder and birches there: a winter treat. Harsh weather brought them into gardens where they rapidly learned to take advantage of seed feeders, and in really tough weather, I could enjoy seeing them in numbers. Now some of them even stay to breed locally. What’s fascinated me about this year’s visitor is how, over the weeks, I’ve seen his rather drab mottled grey cap and shadowy bib darkening towards glossy black, enhancing the bright yellow of his wing bars and rump – all ready to dazzle a prospective mate.
It’s set me reflecting on birds’ plumage and how species differ in the ways they use colour. A pair of robins, also garden regulars, look exactly the same: I can’t tell one sex from the other – though no doubt they can – and they look much as they did in mid-winter. The various species of tits also have little difference between male and female – though in great and blue tits the males’ colours are a little stronger and bolder. We all know about the more striking differences – as in pheasants and, of course, peacocks and, in some of our woodland birds like redstarts and pied flycatchers, and the ready explanation that cock birds need to show off and hen birds to sit tight and be discreet!
It took me weeks of watching to see the changes in my siskin visitor. Then my stepson sent me a photo, taken in his local park, of black-headed gulls. They are striking birds with their grey and white feathers and red legs and bills – and, in summer, both sexes have chocolate brown hoods. In winter these disappear leaving only a dark smudgy mark behind each eye like a beauty spot. Acquiring their dark heads again takes time but Rob’s photo included individuals at each stage of the process. Black-headed gulls loaf about near the Riverside Gardens in Ilkley and you could see the same range there at the moment, but not so neatly lined up as in Rob’s picture!
Jenny Dixon
