Dave Dawson’s natural history notes for 19th July 2018:-
In the exceptionally hot, dry weather, the park is standing up remarkably well. The grasses have died back, awaiting revival in the rains when they come, but deep-rooted perennials remain green and so are conspicuous against the background of bleached grass. The lack of mowing has allowed some species in grassy areas to flower and provide a bit of colour where there’s normally none. The flocks of moulting geese were on or close to the lake, leaving the dry grassland of the public park to a flock of 80 Jackdaws. The graph Jackdaw shows the remarkable increase in Jackdaws in the last five years. Before then there were just a few birds overflying. There were 80 moulting Canada geese, which is a little lower than in recent years. The Egyptian and Greylag geese rival the Canadas with counts of 30 and 50 respectively. The Watersports team have been cutting and hauling out the Small pondweed and there is now little left except debris. Diatoms have taken advantage of this, leading to murky water, which is a risk to fish and human health. Despite a freshly dead Carp, others were alive and jumping, and the Grey herons, Great-crested grebes and a single Common tern show that there are still fish to be had. The Mute swan and Coot numbers were little changed from last month, insufficient it seems to help with the waterweed. There were no House martins and only two Swifts. Swifts have declined by around 20% since peak numbers in 2005. We should see more of these two species once the migration begins. The drought has led to the lowest lake level since I began measurements four years ago. It’s 12 cm (5 inches) below the top of the weir, so the brook is a trickle, fed by water seeping through the boards of the weir and supplemented by a little from the waterfall. As the first thunderstorms came on the 27th the waterfall was dry and the water level had gone down a further 4 cm to 6 inches below the top of the weir. The most prominent flowers were in the Glade, where there’s yellow Ragwort and Prickly ox-tongue and purple Spear thistle and Burdock, and there’s still much Watercress and Water mint in the brook. The yellow flowers of Autumnal hawkbit were prominent on the slopes east of the tennis courts. There were no new species found in the Glade. The hybrid hawthorn in Horse Close Wood is half dead, perhaps a casualty of the drought, or maybe just being shaded out by taller trees.