June 2023

Last month we had a comment on the blog, wondering whether the decline of the waterweed could account for the decline of Coots and Tufted Ducks. I did my lake water sampling on the 14th, when I found some scraps of Small Pondweed and Fennel Pondweed struggling to grow, despite the blue-green bacterial bloom. By the 22nd, however, the watersports people were dragging pondweed out of the lake and disposing of in in rotting heaps on the boundary between the stadium and the golf course. The good news is that the pondweeds have begun to grow, and the bad news is that dragging the weed out disturbs the sediment on the lake bottom, releasing pollutants into the lake water. As for those two wetland birds, there is a link between Coot numbers and pondweed. The numbers of Coots had increased gradually, doubling between 1986 and 2013. Then in 2014, in response to a great growth of Rigid Hornwort which is a floating waterweed, numbers doubled immediately (see the first graph). As the waterweeds decreased again over the subsequent years Coots declined back to the numbers seen before the waterweed flourished. The trend is not so obvious for the Tufted Duck, which had peak numbers in 2006 before the waterweed recovery. It was declining before 2014 and its increase then was not so pronounced, but it too has been declining since 2014 (see the second graph). According to the British Trust for Ornithology, the Coot is largely herbivorous in its diet, and a bottom feeder, seizing plant material and returning to the surface to eat it, whereas the Tufted Duck prefers aquatic invertebrates and bivalve molluscs. The difference in diet seems to explain the much bigger response of the Coot to waterweed abundance. On the 22nd several Coots were incubating eggs on nests readily visible from the lakeside promenade

This month there was mixed news on wetland birds. Although two or three Grey Herons remain at the lake, there was no longer one of them at the nest on the island. I fear that a predator has got to the nest. The risk of this may be great, as these herons are likely to be youngsters without much breeding experience. One item of good news, however, was a good number of Swifts, some 30 or 40 of which were hawking over the lake on the 22nd and others were seen on their commuting flights between this feeding area and their distant nests. Clearly the lake remains a vital food source for Swifts. Swift counts are very variable, but this tally is amongst the top four in the 36-year study. The other bit of good news was a Reed Warbler singing in the reedbed near the south-west corner of the athletics stadium. This species was last heard on my standard walk in 2018, so it's good to know that they are still breeding here. Sadly, the place where they were singing is schedluled to be trashed when AELTC's boardwalk is constructed here, should they get planning permission for their intensive lawn tennis development.

Summer flowers were beginning to show: Watercress in the brook, Black Horehound around the edges, Yellow Flag Iris around the Lake (another attraction threatened by the AELTC development proposals),

The 45 Canada Geese was a low number, but these were beyond the island and some may have remained out of sight there. In contrast, the 115 Greylags were mainly just south of the athletics stadium and readily counted, there were several goslings intermingled with the adults. Both species are flightless for around a month in late June and early July when they are susceptible to predation, so they undertake a moult migration to safe places. Sadly, they see our lake as a safe place, which was not so when the Golf Club used them for target practice in July 2010, and AELTC also don't want them because they may enjoy the planned grass courts. These two species can be killed under licence, but only if they are a health and safety risk. They are easily culled when flightless, as they can be driven into an enclosure and dispatched humanely by a vet. As licence applications don't have to be advertised, there's a continued risk that these birds will be killed for no good reason and the many people who feed the birds from the lakeside will not be too happy.

The bund by the Revelstoke Road car park has been spreyed with "roundup" and seeded with a cornfield annual seed mix. The seems to be doing much better than the long-standing "wildflower" patches beside the perimeder of the Great Field. It's notable, however, that the roundup did not eliminate pre-existing plants of Hedge Mustard, Perennial Ryegrass, Ragwort, Hybrid Dock, Ox-eye Daisy and Yarrow.

A native plant has been increasing in the park in recent years. This plant has the unfortunate common name "Stinking Iris", because some people find the smell of its leaves unpleasant when crushed or bruised, an odour that has been described as "beefy". It favours dry soils in woodland and has colonised naturally in tree planting areas beside Horse Close Wood and the nearby car park. There are also a few beside the path leading to the Lofthouse Glade from the perimeter path. I spotted a new plant in the depths of the Wood this month as well. Thinking it would be suitable for the growing conditions under the veteran oak, I scattered some seed in the enclosure two years ago, where it has established and was flowering for the first time this month.

The vegetation of the veteran tree enclosure is under discussion and ideas are welcome. The main purpose of the enclosure is to deter access to the veteran oak, which was threatened by careless actions, such as BBQ disposal. It's remarkable that some 130 species of plant have colonised the enclosure over the last four years. The vegetation has developed by natural colonisation and serves as a barrier to encroachment. We don't want too much woody vegetation, which would compete with the veteran. It also provides colour and valuable habitat and nectaring for insects, but it appears that some regard it as untidy, or in the way. This led to the removal of several Buddleia bushes that were growing beside the pathways, a loss of colour, wildlife habitat and a barrier to encroachment. Leave a comment with your views on this matter. Have we got enough protection from encroachment? What management does it need? 

The park gates were opened at 06:20 on the 22nd, a welcome move for all those who want to run or walk the dog early in the day. Less welcome was a pile of rubble on top of the tree planting beside the tennis courts, some garden waste tipped over the Dog's Mercury at the edge of Horse Close Wood car park and a set of Christmas lights in the same area. Work was under way spreading topsoil into the deep ruts caused by the pub in the park. Without any sign of decompressing the compacted soil, this treatment is expensive cosmetic work, covering fundamental problems and it was being done too late for the AELTC car parking.

The golf course is now wholly closed and can be viewed from the sourrounding land only. Even at this distance, however, a good variety of meadow grasses can be seen, most of which were missed in the "expert" surveys that underpin the greening proposals in the planning application. Failure to look properly has allowed the place to be undervalued.