Friday 11 December 2020

November 2020 notes




When sampling the waterweed with a grab on the 20th I brought up a recently dead coot with fishing line tangled around its tongue and blocking its throat. Although our anglers follow best practice, illicit anglers may not, and I often bring in discarded line.

Leaf fall was in full swing and blowing them off paths was a major maintenance activity in November. As in previous years, however, they were blown across the part of Ashen Grove Wood beside the large children's play area into a heap beside the golf course fence. Quite unnecessary, because fallen leaves are part of the autumn experinece of woodland. Once fallen, there isn't enough wind in the woodland to move the leaves onto the adjacent path. The natural disposal of woodland leaf litter is done by deep burrowing earthworms which take these leaves underground over the winter months and blackbirds toss the leaves to one side to take the worms.
 
Only a few plants flower in November, but there was a great display of Mahonia beside the Revelstoke Road entrance. 
 
On my monthly bird count on the 18th, I noticed that I failed yet again to find any Dunnocks. This year, I've found only one, back in May. Since around 1990 Dunnocks have declined greatly. The first graph below shows the local trend. This species has declined nationally as well, attributed to changing farming practices, as with many other species. This is shown in the second graph below. At first sight it might seem we are just following this national trend. However, The national statistics cover a longer period, and that great national decline was essentially over by 1986, the year my study began. Since 1986, Dunnock national counts have increased slightly, quite the opposite to our local trend. The same is true for London in the national figures. I cannot account for this great difference, but it seems to be something peculiar to our locality.











Still wondering about the effect of the goose trapping on the golf course, I looked at the numbers. Neither the 30 Egyptian geese nor the 95 Canada geese were fewer than expected, so any depletion is small, but the absence of any Greylags in my count suggests that this native species may be suffering. Others who observe the area have seen a decline. The golf club haven't told us the numbers culled. As with all wild birds, Greylag geese are protected. Whilst control of wild birds can be undertaken by licence, Natural England tell us that a successful applicant must clearly demonstrate – with supporting evidence – that:

  • actual damage or a problem is occurring;
  • the species is actually causing the damage or problem;
  • other reasonable and practical non-lethal alternatives have been considered and tried (such as scaring, trapping or proofing);
  • the action is proportionate;
  • and the conservation status of the species will not be negatively affected.

Nuisance is not a reason for licenced control so, typically, applicants put forward risk to human health. Such arguments may be facile where other species that present the same theoretical health risks are not subject to control. In my view, any control of Greylags on the golf course does not meet the evidence test of Natural England. Although the Greylag is native, some have argued in the past that the English populations have resulted from escaped or released birds and so are not natural, but the official advice suggests that this distinction, if it was ever real, has broken down: June 2013: Advice produced by Natural England’s Landscape & Biodiversity Team.

At leaf-fall in previous years, dense smoke has drifted across the lake when the golf club burnt damp leaves in Owl Copse. This year, they have finally stopped this unhealthy nuisance, a most welcome change.

The Mahonia by Revelstoke Road