June 4th, 2010. Late evening, on the third consecutive blue-sky summer’s day. I take a short walk around the southern outskirts of the village, stopping at three or four favourite sitting-spots by the brook. Nothing disturbs the dark, still water, and I put up only a pair of mallard – the male takes wing first with much splashing and remonstrating, then five seconds later the female, equally vociferous. Their ducklings are hidden out of sight.
There are just four small patches of wetland in this district of 12 square miles (not counting the brooks and ditches, and the forbidden lake on the airfield), all of them the beds of former ponds or pools in an advanced state of succession, little bogs really, spongy and dank in the midst of remnant coppices, surrounded by fallen trunks and boughs. They hold water in winter. In one damp bottom, hard by the brook from Histon, arched over by great willows many of which are almost horizontal, is a patch of yellow iris or yellow flag, bright in the gloom, each with three down-curving buttercup-yellow petals as bold as any tropical flower. John Clare calls them water skegg or flags. On one is a small, round, part yellow – part green spider, as if it was in the process of changing colour to match the emerging flowers. I look out over the parkland below Westwick House, loud with sheep. On the ground are rooks, and a green woodpecker, staring. It has a nest somewhere in this coppice of old willows. It flies low over the meadow, in undulating flight, then makes a steep vertical ascent upwards to clamp onto a trunk 20 feet above the ground. A pair of rich brown and dark grey moorhen, with red face-shields nodding and white undertail bobbbing, stray far from the water into the grass. Green legs in green grass. These birds are exquisitely coloured. We forget how beautiful some of our common birds are. Next time you see a moorhen, take a closer look.
Below the bridge that carries the guided busway over the brook, I scan the water for life. It’s not long before I spot a freshwater mussel, and then another and another. If Rose had not pointed them out to me further up the stream on a previous encounter, I would not have seen them at all. They have been right in front of my nose all the time. They are the colour of the greenish mud on the stream bed, in which they’re half-buried, and it is only their smooth oval shape that gives them away. They are dispersed here and there in this part of the brook, many half-open. I retrieve two from the mud, both open and empty. Presumably they have been eaten. By water vole, or heron, perhaps. Freshwater mussels are generally considered to be unpalatable, though the native peoples in North America utilized them extensively. Impossibly, they smell of the sea.