May 2021 – An update

Despite appearances and the best part of a month of rain and high winds, I have managed a couple of ringing sessions at SML. They were so unproductive that I struggled to motivate myself to update the blog. Five hours on the 7th May resulted in just 12 birds, only four of which were new and another five hours yesterday, (27th May), was only slightly better, producing seven new birds and fifteen re-traps.

A high proportion of re-traps is to be expected during the breeding season, especially as the spring migration seems to have come to an end. The best of these was a Reed Warbler first ringed as a juvenile on 9 August 2014 and, even better, a second Reed Warbler, originally ringed as a juvenile on 7 August 2010, almost 10 years and nine months ago, meaning that the bird has made an astonishing twenty-two trips between the UK and Africa. There is still some way to go to beat the BTO record age for the species of 12 years 11 months 21 days.

In between net rounds, I continued to gather evidence to support my case against the excessive dredging of the drainage ditch on the northern side of the reserve. Historically, an increase in the area of reed at the eastern end of the Ley was much publicised, although this was actually the direct result of fencing the perimeter and the exclusion of livestock and grazing rather than management of the water levels. The loss of almost 14,000m2 of reed, since the year 2,000, due to drying out of the reedbed has, understandably, generated no publicity at all from the reserve manager. One result of the lowering of the water table has been the uncontrolled spread of Hemlock Water Dropwort at the expense of reed. The photo below compares the middle Ley in 2010, with about 50% reed, with the situation yesterday and clearly illustrates the total loss of reed in the area. The yellow line of reed in the right-hand picture marks the demarcation zone between the dry eastern part of the reserve and the wettest part of the central Ley, (at about 650m from the eastern boundary.

Looking SW across the Ley in 2015 (left) and 2021 (right)

If I’m honest, after the photos have been scaled to fit on the screen, it requires a bit of imagination to see the difference between the two images. However, thanks to Google Earth, the following aerial shot better illustrates the point I am trying to make. Taken on 30th May 2020, a time of year when the Hemlock Water Dropwort has already reached between 1-1.5m in height and is starting to produce flower buds, whilst the reeds have only reached about 30cm, the paler, silvery green areas show the extent of the dropwort in the dryest region between the public footpath and Marsh Ride, rapidly decreasing in density to the west as it reaches those areas, which are regularly inundated during flooding events. Unsurprisingly, it is particularly abundant along both sides of South Milton Stream, where the elevated and drier banks produced during path construction, together with the spreading of nutrient-rich spoil and fragmentation of its tubers during ditching operations has allowed the species to proliferate.

The extent of Hemlock Water Dropwort (paler green areas) on May 30th 2020 (Image from Google Earth)

In recent years, in collaboration with English Nature, we have been allowing the western end of the drainage ditch to silt up naturally and there has been some improvement, particularly in the central 500m. Exceptional rainfall and a persistent high sandbar in has enabled sediment to deposit in the lower reaches, where the flow is impeded by water impounded behind the sandbar.

The reserve manager has always had a free hand at SML and his work proposals have often been approved without question. Whilst his experience as a groundsman has been useful in managing the grassland and hedgerows around the perimeter of the reserve, his lack of understanding of the principals of hydrology and a preference for “big” engineering projects has meant that almost every intervention involving drainage has had a negative effect on the water table and impacted on the quality and extent of the reedbed. As Nick Baker commented, in his Sept 2019, BBC Inside Out program featuring SML, Hemlock Water Dropwort has been able to outcompete reed over much of the central reserve. Stands of Greater Reedmace have also disappeared as the water table has fallen. The previous dredging was both unnecessary and excessive but the manager seems unwilling to accept this or that there have been adverse impacts.

I am concerned that, once again, the reserve manager is proposing to dredge this channel later this year and I have been lobbying Devon Birds’ Council to ensure this doesn’t happen. The figures below show the surface elevation along the length of the reserve from Mill Lane in the east to the footbridge on the South West Coastal Path in the west. The shaded pink area in the first figure illustrates just how much the water table was lowered following dredging in 1994.

The height of the water table at SML relative to the surface, pre and post dredging in 1994

However, the shaded brown area in the second figure shows the depth of the ditch as measured this month, following a gradual, slow improvement over the last couple of years. The steeper gradient at c. 800m coincides with the location of the boardwalk across the reedbed and marks the point where the flow downstream meets water impounded when the sandbar is intact, allowing sediment to build up. It is likely that the gradient below this point is actually shallower than illustrated but the boundary path deviates to about 15m away from the ditch below the boardwalk and I considered it unsafe to attempt to measure the depth when operating on my own.

Realistically, it is unlikely that there will be much improvement upstream of the public footpath at 400m as dredging along the eastern length of ditch caused a fourfold increase in gradient and the consequent higher flow rate prevents sedimentation from occurring.

The height of the water table at SML relative to the surface in May 2021

Not dredging the ditch will allow sedimentation to continue and the shallowing stream should restore the natural floodplain in the centre of the reserve at the expense of Hemlock Water Dropwort and to the benefit of the reedbed and its associated ecosystem. At the very least, doing nothing and allowing nature to take its course, costs nothing and, if it all goes pear-shaped, can easily be reversed by a man in a hi-vis jacket and a very big digger!

Tuesday 27th April 2021

After a completely clear, windless night with a full moon I wasn’t expecting much in the way of grounded migrants this morning and I wasn’t disappointed! Nevertheless, despite the lack of numbers, there was a reasonable selection including eight species of warbler and the first Reed Bunting, Garden Warblers and Whitethroat of the year. A French ringed Sedge warbler provided the icing on the cake, although this is known to be a local breeder, ringed as a 1st year at Trunvel, Treogat, Finistère, France on 6th August 2018 during its first southwards migration. Now returning to South Milton to breed for the third successive year.

Once again, my time was most profitably spent, between net rounds, clearing more grass from the boards in Marsh Ride. With 42 metres of board now fully exposed, just six remain to be cleared during my next visit.

Final totals were: 1 Blackbird, 5 Blackcap, 2 Blue Tit, 1 Cetti’s Warbler, 3 Chiffchaff, 2 Garden Warbler, 1 Reed Bunting, 1 Reed Warbler, 1 Robin, 6 Sedge Warbler, 1 Whitethroat and 1 Wilow Warbler.

South Milton Ley Biodiversity

One of the major shortcomings at South Milton Ley, identified in the last management plan, was the lack of comprehensive, contemporary information on the flora and fauna of the reserve and the complete absence of monitoring both before or after major projects, which may have affected species distributions and diversity. Since 2015, I have made considerable efforts to encourage specialist teams to visit the reserve and the fruits of their collective efforts have been considerable.

Whilst this blog primarily concentrates on bird ringing at SML, Devon Bird’s current lack of an archivist causes me concern that, in the event of my sudden demise or that of my pc, many records could be lost. Consequently, I have sent copies of species lists to Natural England, who oversee the SSSI, and made the decision to post copies on this blog as well.

My own contribution to today’s lists is minor when compared to the efforts of visiting specialists and, whilst I have made every effort not to omit anyone, it was safer to name the parent groups rather than individuals and I apologise in advance if anybody feels overlooked.

In summary, since the current management plan was written in 2015:

The number of plant species identified has increased from 95 to 208 thanks to surveys by John Day.

The number of arachnid species identified within the reserve has increased from 10 to 26, thanks to Geoff Foale from Salcombe. Insect species have increased from 130 to 877, thanks principally to the efforts of Geoff Foale and members of the Devon Fly Group. Barry Henwood and members of the Devon Moth Group have increased the number of moths from 6 to 174, whilst Dr Martin Luff has increased the number of beetles from 15 to 192.

In terms of vertebrates the number of amphibians and reptiles remains the same at three and four respectively. One additional fish species has been identified, taking the total up to a majestic three and a comprehensive bird list has been compiled with the assistance of Mike Passman, Bob Burridge and Vic Tucker. Only species recorded either within or flying over the reserve have been included and several rarities, shearwaters, divers, auks and waders, recorded either in the bay, on the beach or at South Huish are now omitted. The current avian total stands at 202 species.

Finally, local resident John Ward has recorded fourteen species of bat adjacent to the reserve and Jess Smallcombe and Ellie Knott of the Devon Biodiversity Records Centre have just provided conclusive proof of the presence of both Water Voles and Otters, taking the mammal total up from 22 to 32 species. Species lists for all of these groups can be accessed here: South Milton Ley Species Lists

Monday 19th April 2021 – Avian lockdown?

Another cold and frosty start greeted me this morning and, for the second time in a row, conditions were almost perfect for ringing with just a gentle NE breeze and clear skies. However, the persistent blocking area of high pressure over the UK seems to have stopped migration in its tracks with birds being held up in N Africa and S Europe. It was as if they were observing their own lockdown! An all-time spring low of 18 were trapped in a five-hour session with just six new birds amongst them. The first Sedge and Reed Warblers of the year and three passage swallows provided a glimmer of hope but my time was more profitably spent continuing to clear grass from between the boards in Marsh Ride using hand shears.

Final totals were: 1 Blackbird, 3 Blackcap, 2 Cetti’s Warbler, 5 Chiffchaff, 1 Reed Warbler, 2 Robin, 1 Sedge Warbler and 3 Wren.

Friday 9th April 2021 – A little bit of quality

Adult male Cirl Bunting

I’m not keen on cold mornings and was not exactly overjoyed whilst clearing ice from the mist net poles and ringing table at 06:30 today. However, despite the low temperature, conditions were almost perfect for ringing with virtually no wind at all first thing. Unfortunately, there were virtually no birds either! Just 24 were trapped in a six-hour session and fourteen of these were re-traps. There was little evidence of passage of any kind apart from a solitary Grasshopper Warbler reeling away somewhere in the reedbed and a lone swallow which moved through later in the morning.

It wasn’t all bad though. Two of the re-traps were resident male Cetti’s Warblers and another four were local Chiffchaffs returning to their breeding site for the second or third year in succession. Of the new birds, the highlights were an adult male Cirl Bunting and a late Siberian Chiffchaff, both of which were trapped in nets beside the STW. There cannot be many places in the country where a ringer can trap Cetti’s Warblers, Cirl Bunting and Siberian Chiffchaff in the same ringing session.

Siberian Chiffchaff Phylloscopus collybita tristis

The lack of birds gave me the opportunity to start spring cleaning the boards across Marsh Ride. These gradually disappear under a thatch of grass if left untended, which makes it all too easy to misjudge where their edges are. In the interests of my personal health and safety, I like to cut away the grass to expose the boards. This is a slow process, using edging shears to slice through the matted roots along both sides of the net ride, a total distance of 96 metres. Once completed, the cut material must be raked to one end of the ride for disposal. It’s surprising just how heavy wet, matted turf is! All that remains now is for me to repeat the exercise, using hand shears, and cut the remaining 48 metres between the boards along the middle of the ride. This will enable me to set the bottom of the net a little lower in future, rather than having to avoid birds in the bottom shelf potentially encountering cold damp vegetation. Final totals were: 2 Blackcap, 3 Blue Tit, 2 Cetti’s Warbler, 8 Chiffchaff, 1 Cirl Bunting, 2 Long-tailed Tit and 6 Wren.

Tuesday 30th March 2021. Back in business!

The first stage of the easing of the current lockdown restrictions on travel came into force yesterday and, armed with a copy of an email from the BTO making it clear that voluntary work and environmental monitoring are both exempt from the covid 19 restrictions, I left the boundaries of Plymouth for the first time in four months and made my way to SML.

The bridge at Marsh Ride prior to being dragged back across the two metre gap

I wasn’t sure what was going to greet me, knowing that the bridge to Marsh Ride had been swept off its mountings by floodwater back in December and half-expecting some of the rides to be blocked with fallen branches and vegetation. In the event, things weren’t too bad. Unlike the first lockdown, there had been little plant growth during the winter and nets were quickly erected beside the sewage works and in Blaca Ride. Accessing Marsh Ride was more problematic but I had come equipped and managed to haul the heavy wooden bridge back across the two metre wide ditch and onto its mountings about thirty minutes later. With hindsight, it was lucky that the bridge hadn’t been swept away completely and Nick Townsend and I will hammer in posts to secure it and prevent a recurrence.

Back on its mountings!

From the ringing point of view, things were less than perfect. The north-easterly breeze, blowing down the valley, was stronger than forecast and there was no evidence of visible migration. Despite this, a pair of Reed Buntings, Chiffchaffs and the odd Blackcap were singing in the reserve and two male Cirl Buntings were vocal just outside the boundaries. Twenty nine birds were trapped, just over half of which were new, including 9 Chiffchaff and a Willow Warbler. The re-traps were dominated by Dunnocks and Wrens but also included 2 Cetti’s Warblers, and 2 returning Chiffs, a Willow warbler and a Blackcap. Final totals were: 3 Blackbird, 1 Blackcap, 2 Cetti’s Warbler, 11 Chiffchaff, 4 Dunnock, 1 Long-tailed Tit, 1 Robin, 1 Willow warbler and 5 Wren.

Tuesday 1st December 2020

Sunrise at South Milton Ley

Today’s weather forecast was too good to ignore, with a light northerly breeze expected. Any wind direction between NW and NE is ideal for trapping Chiffchaffs by the sewage works at SML as the midges (and birds) concentrate on the leeward side of the plant where I have 30m of nets. Unfortunately, the prevailing SW wind usually means that the birds gather frustratingly on the other site of the works. Nothing is ever perfect though and the bright sunshine made the nets a little too obvious resulting in a lower catch than last Thursday, although another 19 Chiffs were processed, including the first Siberian Chiffchaff of the winter.

Siberian Chiffchaff

The other highlight was a 1st year male Sparrowhawk, caught in the bottom of Blaca net by just one leg. I approached it cautiously, not wishing to fall foul of its flailing talons or bill but, in the event, it was extracted quickly and without any blood spilled. I wasn’t so lucky when I processed it. A momentary lapse of concentration enabled it to latch the talons of its right foot onto the end of my right index finger. This is not the first time this has happened and I have had to be extricated from the grasp of a particularly aggressive Kestrel chick in the past. However, with no one else to assist and the bird increasing its grip every time I tried to free my hand, I had to use some initiative or let the bird go without weighing it. Fortunately, I was able to hold my pen in my mouth and use the tip to gently prise the hind claw off my finger whereupon the bird let go!

1st year male Sparrowhawk

Final totals were 36 birds with 28 new: 1 Blue Tit, 1 Cetti’s Warbler, 18 Chiffchaff, 1 Dunnock, 1 Siberian Chiffchaff, 1 Firecrest, 1 Goldcrest, 1 Reed Bunting, 3 Robin, 1 Sparrowhawk and 5 Wren

Friday 27th November 2020

Firecrest

Unlike some other ringers in the South Hams, I had decided that, although permitted, travelling to my ringing site during the Covid crisis constituted an unnecessary journey and I have been twiddling my thumbs at home for the last few weeks. However, given a welcome break in the weather and the knowledge that other visitors to the site are few and far between, I finally succumbed to temptation and travelled to South Milton for a dawn start today. Unfortunately, the forecast of an overnight frost and low winds turned out to be woefully inaccurate with a steady force 4 NE breeze blowing down the valley, which is at the upper limit for such an exposed site. On a positive note, the wind had prevented a frost and overcast skies made the nets less obvious.

Birds waiting to be processed – different colours = different nets!

As is usual at this time of year, things started off slowly and gradually picked up as the morning progressed. Chiffchaffs dominated the catch, with two Firecrests providing the highlight. The last bird trapped was a female Great Spotted Woodpecker, which got its revenge for the indignity by drilling my knuckles as I extracted it.

Woodpecker damage!

Final totals were 56 birds of which 46 were new: 5 Blue Tit, 1 Chaffinch, 33 Chiffchaff, 2 Firecrest, 2 Goldcrest, 1 Great spotted Woodpecker, 6 Long-tailed Tit and 6 Wren.

Wednesday 4th November 2020

After two weeks of seemingly endless gales and rain, I managed to squeeze in a morning’s ringing before the next national lockdown starts tomorrow. It was a cold start with the first frost of the autumn and the mist net poles were covered in ice when I arrived, but things gradually warmed up despite a northerly breeze blowing down the valley. Ringing was steady but not very exciting. Crests seem to be thin on the ground this year but at least there were a few Chiffchaffs about, including 3 returning wintering birds – two from 2019 and 1 from 2018. The highlight was five Cetti’s Warblers, four of which were new birds. This brings the year’s total so far up to 22 individuals, which may be a record for SML. I’ll have to check!

A couple of Sparrowhawks, which appeared to be hunting as a pair close to Marsh Ride, kept me on my toes, as did a sighting of a stoat scuttling across one of the paths in the same area but my presence kept them away from the nets. Woodpigeons were much in evidence as well with at least a thousand heading south during the morning, together with about 20 Skylark and a couple of Siskins. Final totals were 46 birds of which 29 were new: 1 Blackbird, 4 Blue Tit, 5 Cetti’s Warbler, 15 Chiffchaff, 3 Dunnock, 4 Goldcrest, 2 Great Tit, 1 Great spotted Woodpecker, 2 Long-tailed Tit, 2 Robin, 1 Song Thrush and 6 Wren.

Friday 16th October 2020

Lesser Redpoll

With a scattering of transatlantic and eastern vagrants in western Europe and high numbers of Yellow-browed Warblers reported from Shetland to Land’s End, I was cautiously optimistic this morning. Unfounded optimism as it turned out. Crests and YBW being conspicuous by their absence. There were good numbers of Chiffchaffs though, including the first returning bird of the winter, and today’s highlight was the first Lesser Redpoll I have ringed at SML. Six Redwing and a single Fieldfare were feeding on berries in the hedgerows but were extremely mobile and avoided the nets. In the end I reached a respectable total of 52 birds of 13 species, 47 of which were new: 1 Blackbird, 1 Blackcap, 4 Blue Tit, 1 Cetti’s Warbler, 31 Chiffchaff, 1 Dunnock, 1 Goldcrest, 3 Great Tit, 1 Great spotted Woodpecker, 1 Lesser Redpoll, 3 Meadow Pipit, 1 Song Thrush and 3 Wren.