Williamson's Weekly Nature Notes January 21 2009

They are all divers of course, so they can get away from a wandering greater black-back gull. But only for a minute. Then they have to pop back up and face the enemy.

Just look how these three species solved the problem millions of years ago. I took my pictures at the Arundel Wildfowl and Wetlands Trust, which is open every day of the year except Christmas Day. Though two of the three are mainly marine species they are quite happy to live on those clean freshwater ponds fed by chalk springs.

First the pair of long-tailed ducks: he in evening dress, she in a goldy-brown gown. These ducks are often mistakenly called pintails because of the long tail feathers also sported by the pintail drake. See how his black patches copy the shadows in water ripples. Very confusing for the enemy with everything blending and sliding continually into new shapes.

In summer when he leaves us for the high Arctic, he changes that evening dress for a ball gown like his wife's. He is, after all, going to have to live in tundra pools in which small reeds and grass grow. Though she will moult she stays brown, and her head becomes sooty-brown.

I have always found it odd that in winter she does not take his advice in dress code and adopt the colours of the ocean with their white spray and black wavelet shadows.

Still, she survives. Long-tails are very rare now in Sussex. One or two are seen each winter off Pagham, but only 30 years ago 20 were seen each year, and a century ago small flocks. The old Sussex name for them was 'sea pheasant'.

The other two ducks I saw at Arundel are a goldeneye (top) and a tufted duck (below). Both are drakes. At present there are half a dozen goldeneyes in Fishbourne channel and some more in Nutbourne channel. But they could be anywhere in the harbour until mid March.

Tufted ducks are here winter and summer but mainly on the gravel pits, hammer ponds and lakes throughout the county. Here again, tufted females dress in brown and tend to keep to the margins of lakes more than the drakes.

Goldeneye females split the difference and are dull grey. But of course camouflage is not the only thing on the mind of a male duck. Showing off to other males and their wives with an impeccable white shirt comes into this complicated dress code as well.