I feel like I have been practicing self-isolation for the last five weeks in anticipation of the inevitable spread of Coronavirus. Record breaking rainfall totals and high winds made ringing impossible and led to a gap of 40 days between visits to the reserve, the longest since I started ringing there. On the bright side, at least I have valid reason now to ask visitors to keep their distance rather than try to hold a conversation while I’m trying to concentrate on processing and releasing birds!
Personal hygiene has been a priority for me whilst ringing, ever since contracting Giardia at SML a couple of years ago. A particularly unpleasant gastric parasite, associated with faecal material, it proved beyond the testing and diagnosis capabilities of the NHS and my degree in applied and environmental microbiology was my saviour in that, after three weeks of discomfort and pain, I was able to self-diagnose and arrange private tests and appropriate antibiotics rather than waiting another ten days for the NHS to conduct yet more tests. Just two days after starting the antibiotics things started to improve!
One fortunate consequence of the parasite was that I stocked up on medical-grade, alcohol-based hand gel at a budget price – surplus stock from the Canadian health system, which was originally procured during fears of a SARS outbreak. I now have six litres of the stuff at home, probably enough to last my entire ringing career. I’ll be selling it on street corners as the current outbreak progresses!
Not much need for it today though. All the wintering Chiffchaffs and Crests have departed, leaving behind just resident species and the first few, returning male, breeding Chiffchaffs, some of which were adorned with the pollen of eucalypts, presumably picked up as they crossed N Africa or Iberia. At least three Cetti’s Warblers were singing at various points around the perimeter of the reedbed and three Water Rails appeared to be holding separate territories. Bird of the day was a beautiful Barn Owl, which sat briefly on a pole in the sunshine beside marsh ride before flying to cover.
Ringing was slow, with just 14 birds trapped, and only three between 9 and 12am, when I packed up: 3 Cetti’s Warbler, 6 Chiffchaff, 1 Reed Bunting, 1 Robin and 3 Wren. Things can only get better!
Ringing at this stage of the winter is often unproductive as most wintering birds are already ringed and many are starting to move on. The increasingly mild winters have also significantly reduced the numbers of wintering thrushes, finches and buntings so I wasn’t expecting a great deal today. My expectations were realised with just 16 new birds processed together with 36 re-traps. Totals included 24 Chiffchaff, 7 Goldcrest, 5 Firecrest and a solitary Reed Bunting.
I took advantage of the low workload to put the finishing touches to the bridge to Marsh Ride. It’s now covered with wire mesh to provide grip and sufficiently clear of the water to prevent the mesh from trapping floating vegetation in the future.
I also walked around to Horswell Ditch to check on the stability of the bank I rebuilt at the weekend. It’s still there at the moment! Only time will tell if I have done enough but the water level has risen to the top of the sluice and was pouring merrily over the top, which is a good sign.
The winter reed cuts at South Milton have always reminded me a bit of ‘Dad’s Army’, with a team of, not exclusively but largely, elderly volunteers and somewhat unreliable equipment. This impression was reinforced this morning when, after a night of heavy rain, the reserve manager gave a fantastic imitation of Private Frazer (you have to imagine a dour Scottish accent here!) – “We’re all doomed – nay body will turn up – the reeds will nay burn – you should have cancelled!”
These fears proved unfounded and 27 volunteers made short work of clearing the last of the area we started two weeks ago. It was damp underfoot but the reedbed remains alarmingly dry considering the rainfall we have received in the last few months. Around a hectare was cut in the end, fully meeting our stewardship obligations.
I contributed very little on the day but concentrated on fixing a major leak beside the sluice on Horswell Ditch. Despite repairs by our contractor last autumn, the pressure of retained water had once gain punched a hole through the soil beside the sluice, partially draining the ditch. Vic and I managed to reduce the flow by jumping up and down on the earth above to compact it. I then spent the morning digging out and carrying shovel loads of clay to consolidate the bank, trying to build up a sufficiently robust buttress of soil upstream of the sluice. I finished off by topping the repair with turf in the hope that plant roots will help to reinforce and stabilise the bank.
Two of my extra duties during the reed cut on Sunday, initially car park attendant and later a dash to a filling station for fuel for the cutting machines, enabled me to keep an eye on the Chiffchaffs around the sewage works. Numbers gradually rose as the morning progressed and peaked around midday and there were plenty around when the sun was at its highest. The current area of high pressure has led to sharp frosts, but the associated dry weather and light NE breeze are the perfect conditions for trapping beside the sewage works as both insects and birds drift towards the net rides.
Consequently, together with my wife Nikki, we deliberately arrived a little later than usual and set up the maximum number of nets possible downwind of the works. Numbers did not disappoint, and 53 birds were trapped in around four hours. Just over half of these were re-traps, which is normal here for this stage of the winter, but the total included 23 Chiffchaffs, 7 Firecrests and 4 Goldcrests. In fact, except for one female Bullfinch, all of the birds caught were insectivores highlighting the importance of the midge population breeding in the sewage works.
My long-suffering wife has always been supportive of my ringing and frequently accompanied me during my training, visiting Icklesham and even sleeping in a bird hide in Portugal for two weeks but she’s definitely not a fan of the early mornings! Today’s later start persuaded her to accompany me. I had forgotten how much easier it is to erect the nets with two people and how having someone else to scribe speeds up the ringing process so, although tiring, the day was much more relaxed than it might otherwise have been!
The first stable area of high pressure since last September produced a beautiful sunny day for the first reed cut of the winter. Although cold, the physical efforts of the 20 or so volunteers and the subsequent burning of the cut reeds kept everyone warm. Unfortunately, the Devon Birds’ reed cutting machine suffered a major breakdown for the third successive year, which reduced the area cut. However, thanks to the personal efforts of Rory Sanders, who had purchased a second machine for parts we were able to continue and cut and burn around 5,500m2.
None of this would have been possible without the sterling efforts of Nick Townsend, who had dug down through the compacted sandbar at South Milton Sands, allowing the water impounded within the Ley to drain in time for the cut.
More of my and James Day’s photos can be seen in the following gallery.
The first calm and sunny day of 2020 drew me to SML like a moth to a flame. After two weeks of dull, wet and windy weather confining me to home, I was starting to get cabin fever and, although bright conditions make the nets more visible and can reduce catches, knowing that the forecast for the next week is grim saw me slopping through the mud at 8am. In the not too distant past decent numbers of Reed Buntings roosted in the reedbed in winter and up to nine birds could be found together in the same net. However, these have declined significantly in recent years and, apart from the odd Cetti’s Warbler, the reedbed nets are not very productive in mid-winter. Consequently, I decided to try Crest ride at the wooded, eastern end of the reserve as an alternative, which provided a quarter of the birds trapped.
Catches in previous Januarys have ranged between 12 and 73 birds, depending partially on weather conditions and the number of visits, but principally on the presence or absence of chironomid midge swarms. Midges were few and far between today and the number of birds trapped reflected this with a final total of 28 of which just 14 were new. Five of the re-traps were Firecrests, a bird which manages to brighten even the dullest of days. Birds processed: 3 Blue Tit, 1 Bullfinch, 8 Chiffchaff, 1 Dunnock, 5 Firecrest, 4 Goldcrest, 2 Great Tit, 1 Robin, 1 Song Thrush and 2 Wren.
Given the continuing overcast weather, combined with other commitments over the festive period, I decided to make a start on revising some of the other pages on this blog. I’ve been working on a paper detailing the population dynamics of Chiffchaffs wintering at South Milton Ley. British Birds sent the first draft out to five reviewers and it returned with a lot of comments. Fortunately, these were almost entirely constructive and I have recently resubmitted a significantly revised second draft. When (or if) this is eventually published, I intent to expand the section on wintering Chiffchaffs in the blog considerably. However, in the meantime I have updated and sorted all the photos of Siberian Chiffchaffs ringed at SML since December 2014 into a thumbnail gallery, which can be accessed here:
Firstly, a happy and productive New Year to my handful of regular readers. My last day’s ringing at SML for 2019 turned out to be the least productive session ever with just one new bird and six re-traps caught in four hours with 90 metres of net erected. A minor consolation came in the form of a UK control Chiffchaff but everything was hard work. The weather was particularly gloomy with enough moisture in the air to condense on the nets requiring more frequent rounds than usual. The wind, although light, was from the southwest, the least favourable direction for trapping around the sewage works in winter and the ground was saturated making progress between and along the net rides slow and hazardous. Even my lightweight Daihatsu 4×4 with the diff-lock on struggled to find enough grip to get me and the ringing gear on-site.
I tend not to visit on days like this as experience has shown that most Chiffs are present when it’s calm and sunny, which encourages chironomid midges to swarm around the sewage works. It does make me wonder where the birds go when the weather is less favourable. Perhaps they feed in woodland and large private gardens further up the valley on days like this. Ringing in previous winters has shown the minimum population at SML to be around 90 birds with estimates, made using capture/recapture models, suggesting that the true figure could lie between 188 and 227. That’s a lot of disappearing birds!
Crops of photos taken recently at South Milton Ley by Richie Moore, published on the Devon Birds’ website and reproduced here, clearly show the importance of chironomid swarms to wintering insectivores when the sun is out. Reassuringly, all the birds have rings on!
A forecast for a brief period of benign weather and a much-improved back injury encouraged me to visit SML today. I had gone principally to work on the bridge to Marsh Ride as the water levels in South Milton Stream have overtopped the bridge a couple of times this winter, flipping it and moving it a few metres downstream. The resistance to the flow, caused by the boards, had also forced water up onto the banks at either end, softening them and causing the bridge to slowly sink. If left unresolved the whole lot could have been washed away or fallen into the stream during the next heavy downpour.
I had been racking my brain for an easy solution and came up with the idea of cutting and reconfiguring the steel bases from an old sofa and armchair we have just replaced to make support structures for both banks. These were hammered into a depth of c.50cm leaving the boards 20cm clear of the surface and any future overtopping of the stream. All at no cost as the metal was destined for the recycling centre!
The boards are like a skating rink as the chicken wire had collected a load of floating vegetation and eventually partially ripped off leaving a slippery wooden surface. Replacement wire mesh is on order! Despite not being finished, it already feels more stable and secure than I can remember. As a bonus, I have used the two, heavy, original boards together with two beams salvaged from the boardwalk bridge to extend the walking boards along the whole length of the net ride for the first time.
In between periods of construction, I had six nets (90 metres) up. Those beside the sewage works were particularly productive. These can only be erected on its SW perimeter and, in winter, the prevailing wind frequently concentrates insects and birds on the opposite, leeward side of the site, often resulting in frustratingly low rates of capture and recapture. The numbers trapped increase on calm days or when the wind has a northerly or easterly direction. Today, both of these criteria were met resulting in 58 birds being processed: 1 Blackbird, 8 Blue Tit, 28 Chiffchaff, 3 Dunnock, 4 Firecrest, 4 Goldcrest, 1 Great Tit, 1 Long-tailed Tit, 1 Reed Bunting, 1 Robin and 6 Wren.
A second back injury in 10 months has kept me virtually confined to the house for the last couple of weeks. All very frustrating as a couple of perfect ringing days passed by and other birders phoned up to tell me the Ley was “awash with Chiffchaffs” with possible sightings of Yellow-browed Warbler and Siberian Chiffchaff as well. With today looking like the only opportunity to ring for the next week, I bit the bullet and made my way to South Milton. In the event, I only erected the three nets closest to the ringing station as every step to the reed bed rides sent a jolt up my spine and the recent high water levels have stripped away some of the chicken wire on the bridge rendering the boards extremely slippery.
Consequently, numbers ringed were lower than usual with 30 birds processed: 1 Blackbird, 5 Blue Tit, 1 Bullfinch, 14 Chiffchaff, 4 Firecrest, 3 Goldcrest, 1 Redwing and 1 Wren. The Redwing was the first of the winter and was lured into a net using a tape known in ringing circles as “The Latvian love song”, which seems to have some sort of fatal attraction for the species.