Today was the last CES session at Lower Moor Farm for 2022. I have a big decision to make: is it actually the final CES session at this site? Today we caught a measly 19 birds. Admittedly it was a freak, but on the 20th August 2014, my fourth visit to the site, I felt like a quiet session, so I just set the three 18m nets that now comprise ride 2 of my constant effort site, known as the Heronry Ride by the Trust.
In that session I actually caught 157 birds from 15 species. Today that ride delivered 12 birds from 7 species. It was the best return of any of the rides. Why the difference? I suppose the first thing to say is that the huge catch was a freak: and I have never got close to that since. 90 of those birds were migrant warblers. The second thing to say is that the structure has changed significantly. Although the path is still there and open, at the time the foliage that forms the barrier between the Heronry Ride and the adjacent path to the third hide on the site, was thinner and much lower. Between the path and the stream that forms the boundary between Wiltshire & Gloucestershire the willows were interspersed with massed banks of bramble, and I am certain it was the fruits of that which pulled them in.
In the following years the Trust became somewhat enamoured of creating scallops along rides, as a way of improving the habitat for butterflies and other insects. However, that required the removal of most of the bramble, the idea being that they would be replaced by wildflowers / plants that were more attractive to the insect world. Two things: the wildflower planting never happened, and the open spaces need continual maintenance to keep them open, which has also not happened. Since then, the stream-side woodland has closed in, and the open spaces have become completely occupied by nettles. I have nothing against nettles, but I don’t think they are particularly attractive to pollinators, whilst being a wonderful food plant for the offspring of so many insect species. The simple fact is, though, that what attracts the birds into that ride in the autumn is the crop of blackberries that now no longer exists.
Up until 2020, the small area adjacent to ride 2, known boringly as ride 1, was a single 12m net in the only patch of true woodland within the CES site. It was never a great catching net, but it did catch the odd excellent bird: Green Woodpecker and Kingfisher for two. In 2020 two of the trees collapsed, blocking the ride and the Trust decided on a new policy for the area. The Heronry Ride was put out of bounds to the general public, and the plan is to rewet the woodland area. I love the idea, even if I did lose one of the rides from the CES. As part of the programme, quite a lot of thinning happened along the stream side (I know, because I had to remove quite a lot of cut wood from the ride path prior to my next CES session!) but not on the opposite side. This thinned area has, once again, been colonised by nettles.
Then we move on to ride 4. Ride 4 runs from the gate into the wildlife refuge for a length of 2 x 18m nets. What started as a line of mature trees along the stream side, and a few low trees and scrub between the ride and Mallard Lake, has now grown up, and the numbers of birds have also dropped significantly. It will take a considerable amount of thinning work to turn that around. I think that is enough doom and gloom. The following table shows exactly what has happened. It is as if 2019 marked the high-water mark and 2020 destroyed the integrity of the CES site:
There is a lot of effort that goes into a CES. Twelve sessions between May and the end of August, roughly 10 days apart, and I would work mine for 5.5 hours at a time. If I am going to be processing fewer than 30 birds per session, i.e., less than 6 birds per hour, that is not a good use of my time, nor is it providing much by way of training for my team – and there is only so much coffee one can drink in a session. If the Trust allows me to thin out rides 2 and 4 over this winter, then I will try it out for another year.
Anyway, the results from this last session were: Blue Tit 1; Great Tit 2(1); Wren 1(1); Dunnock (2); Robin 1(2); Blackbird 4; Blackcap 2; Chiffchaff 1; Bullfinch 1. Totals: 13 birds ringed from 8 species and 6 birds retrapped from 4 species, making 19 birds processed from 9 species. All birds processed were birds fledged this year.
The total catch for the CES this year was: Sparrowhawk ; Green Woodpecker 1(1); Treecreeper 1(5); Blue Tit 2(7); Great Tit (5); Long-tailed Tit 1(6); Wren 3(7); Dunnock 1(14); Robin 2(13); Song Thrush 2; Blackbird 3(8); Cetti’s Warbler 1(5); Blackcap 6(20); Garden Warbler 5(3); Whitethroat 2; Chiffchaff 2(13); Willow Warbler ; Chaffinch ; Bullfinch 1(1); Reed Bunting . Totals: 33 adults ringed from 15 species, 215 juveniles ringed from 19 species and 108 birds retrapped from 14 species, making 356 birds processed from 20 species.
It is still a lovely site, and I have every intention of continuing to work there, but I feel that I need to explore other areas of the site, mainly within the wildlife refuge.