Bird Ringing at South Milton Ley

This is a blog which concentrates on the day-to-day bird ringing activities at South Milton Ley Nature Reserve, a 16 hectare reedbed in south Devon. The title reflects the fact that it takes me about an hour to drive to the site from my home and a further hour to set up all of the nets. This makes for some very early starts, particularly in the summer months!

If you stumbled across this website whilst looking for up to date information about the birds recorded here, at South Huish Reserve, South Efford Marsh, Thurlestone Bay or simply in the general area I recommend visiting Mike Passman’s excellent website: Thurlestone Bay Birds

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5th and 11th July 2018

The exceptional warm and dry spell continues with little sign of change in the immediate future. I’ve been getting the nets opened for 06:00 as it’s cooler then and the birds are more active. By midday it’s just too hot! At least the paths around the Ley have finally been mown. Trudging through knee high grass between the net rides and the ringing station for the last two months was no fun either. Nick Townsend and a colleague arrived at 09:00 to erect new signage to reflect the new, more-relaxed access policy implemented by Devon Birds. Unfortunately, the ground probably couldn’t be harder than it is at the moment so I don’t know how they got on trying to hammer in posts to attach the signs to.

The ringing on both days was steady and is now dominated by the offspring of local breeders. The grand total for the two days was 88 new birds: 2 Blackbird, 11 Blackcap, 3 Blue Tit, 1 Bullfinch, 13 Chiffchaff, 8 Dunnock, 3 Great Tit, 1 Reed Bunting, 23 Reed Warbler, 4 Robin, 6 Sedge Warbler, 3 Song Thrush, 1 Whitethroat and 9 Wren.

Objective 7

Prasocuris phellandrii

Prasocuris phellandrii © Geoff Foale

It’s not all about the birds at SML. Objective 7 of the current management plan seeks to fill gaps in our knowledge of the flora, fauna, hydrography and chemistry of the reserve. To that end, members of the Devon Moth and Devon Fly Groups have visited in the last couple of years and Dr Martin Luff is currently working on beetles there. Together, they have produced an arthropod list, which now stands at an impressive 712 species. No individual has added more to the list than Geoff Foale from Salcombe and he continues to turn up new species at almost every visit. Coupled with the fact that these are usually documented by high quality photographs, I will use this blog to publicise his efforts.

Actually, the beetle in the header photo, Prasocuris phellandrii, was identified independently by both Geoff and Martin. It normally feeds on Marsh Marigold (Caltha palustris) and Geoff reports that “they are uncommon in this part of the country with only 3 previous records for the whole of the south west area on NBN”. The latest discovery, the Alder Signal Moth (Stathmopoda pedella) could be one of the first records west of Bristol.

Stathmopoda pedella

Alder Signal Moth (Stathmopoda pedella) © Geoff Foale

22nd and 29th June 2018

Treecreeper

June is never the most exciting month at South Milton with the ringing dominated by local breeders so there is little of interest to put in the blog. I have pooled together my last two visits, both completed during the current prolonged spell of good weather. Even then, there were a couple of surprises with an adult female Yellowhammer being the last bird trapped on 22nd and a young Treecreeper finding its way into a net on the 29th. Neither of these species is annual at SML.

In total 67 birds were caught of which 11 were recaptures: 3 Blackbird, 7 Blackcap, 11 Blue Tit, 2 Chiffchaff, 2 Dunnock, 3 Greenfinch, 3 Great Tit, 1 Great Spotted Woodpecker, 1 Reed Bunting, 16 Reed Warbler, 4 Robin, 6 Sedge Warbler, 1 Treecreeper, 1 Whitethroat, 5 Wren and 1 Yellowhammer. One of the re-trap Reed Warblers was first ringed as a juvenile way back in 2011.

Wednesday 13th June 2018

SML Horswell Ditch 13-06-2018 1

Horswell Ditch – nine months after excavation

With the weather forecast to deteriorate tonight, I squeezed in a ringing session this morning. Not the most exciting of days but pretty typical for the middle of June. Just 27 birds of which 7 were recaptures and one a control Reed Warbler. This has probably come from Slapton Ley. Wrens and Blue Tits made up the bulk of the new birds but these also included the first juvenile Chiffchaff and Sedge Warbler of the year.

Things were so quiet at one point that I strolled across to look at the new ditch. The water level has dropped recently, exposing muddy banks but vegetation is already re-establishing after last year’s excavations. There were four species of damselfly and dragonfly present and I spotted a young frog close to the sluice. This is the first amphibian I have ever seen at SML so it looks as though the hoped-for increase in biodiversity has already started!

Wednesday 6th June 2018

Another fine day tempted me out again today to complete clearing the net rides. Ringing produced 21 new birds: 1 Blackcap, 1 Blue Tit, 2 Long-tailed Tit, 8 Reed Warbler, 7 Robin, and 2 Sedge Warbler. 16 re-traps included a further 10 Reed Warbler and 2 more Sedge Warbler. There were plenty of juveniles of the resident species knocking about and the first juvenile reed warbler of the year was ringed.

Saturday 2nd June 2018

It’s been a while since my last blog entry, partly because of a week off waiting for my stitches to come out but mostly because I was struck down with a particularly nasty intestinal bug, which showed no sign of improving. Tests followed, then more tests, followed by bloods and x-rays before a diagnosis was reached two weeks later. Turns out I had picked up Giardia, a water-borne parasitic flagellate, which attacks the lower intestine, most probably caught whilst splashing through the mud and water at South Milton when clearing the net rides on my last visit. It turns out that David Walliams caught the same bug during his charity swim down the Thames.

Fortunately, things improved rapidly after a course of antibiotics although I’m not 100% even after three and a half weeks. Nevertheless, I felt fit enough to get to SML on 2nd June and face up to the task of clearing the net rides again. I started at the seaward end. These rides had been under a metre of water during the late winter but were accessible now and the soft young reeds only took about thirty minutes to clear. The net rides by the sewage treatment works were more problematic and were at risk of being swamped by hemlock water dropwort. It still amazes me how much bramble and willow can grow in a few weeks as well.

Anyway, I carried on clearing vegetation until my batteries ran out then set up a few nets at about 9am. This turned out to be surprisingly productive, with 68 birds caught and a reasonable variety: 3 Blackbird, 4 Blackcap, 4 Blue Tit, 4 Chiffchaff, 4 Dunnock, 1 Garden Warbler, 1 Goldfinch, 2 Greenfinch, 1 Great Tit, 23 Reed Warbler, 4 Robin, 11 Sedge Warbler, 3 Whitethroat and 3 Wren.

Conversion: From Corvids to Cuckoos

CuckooDuring the years with my former trainers, I used to ring regularly throughout the breeding season at several sites on Dartmoor where Cuckoos were often present. To increase our changes of trapping these difficult birds, I set about making a series of lures using plastic Magpie decoys. In the end I produced three, a male, a female and a hepatic female, which covered all the options and proved reasonably successful in attracting the birds to the netting areas, when used together with a tape.  When I changed trainers at the start of 2017, I left the decoys behind, as it has been some years since Cuckoos last parasitized Reed Warblers in Devon’s reedbeds and they would have been little use to me at South Milton.

When we returned from Crete, I received an email from a colleague, who operates a CES on Goss Moor in Cornwall, asking to borrow a decoy. Unfortunately, I couldn’t help but I’ve just had a skin cancer removed from my face and although the area affected was relatively small it’s left a big hole, which needed sixteen stitches to patch it up. Consequently, I’m not allowed to do much as the surgeon has forbidden me from ringing until the stitches come out in a week’s time. Apparently, she considers the mud, stagnant water, sewage outfall and rat and bird faeces at South Milton to be an infection risk! Anyway, to keep things brief, I used the time to make a new decoy – a standard female. Let’s hope it proves effective!

Cuckoo conversion

Before and after

Thursday 4th May 2018

My first visit to SML for three and a half weeks and, as expected, the vegetation in the net rides had flourished in my absence. Young reeds are easily dealt with using my rechargeable hedge trimmer but the hemlock water dropwort, which has proliferated in the nutrient rich spoil used to create the paths around the perimeter of the reserve, is a tougher proposition. If left unchecked, the stems of this poisonous plant can reach a diameter of 6cm and once mature, the dry, umbrella-shaped seed heads are a nightmare to remove from a mist net on a windy day. Luckily, almost all the emerging plants were young and tender enough to be dispatched by the hedge trimmer. It will be a constant battle to keep the greenery at bay and the net rides open throughout the summer though.

I had anticipated the vegetation issues and arrived early at 05:30. The main rides were defoliated and six nets erected by 06:30. I cleared another 66m in Crake and Crest rides at the end of the session. On the bird front, things were quiet, with little sign of visible migration other than 19 Whimbrel together with a lone Bar-tailed Godwit in an adjacent stubble field. Clear skies and favourable winds the previous night had given nocturnal migrants no reason to stop. Despite this, 28 birds were trapped including 3 Blackcap, 4 Chiffchaff, 9 Reed Warbler, 8 Sedge Warbler and 1 Reed Bunting. Of the warblers, the majority were males, presumably arriving before the females to establish territories. One of the Chiffchaffs though was clearly female with a fully developed brood patch, indicating that breeding was well underway.

Blackcap S277860

Blackcap S277860 map

The ringing recovery referred to in my previous post relates to a 1st year, male Blackcap, ringed at South Milton Ley on 16th September 2017 and controlled at Puente de Celemín, Benalup de Sidonia, Cádiz, Spain on 22nd November 2017, a distance of 1,554km almost due south of SML.

No great surprise in the location, slap bang in the middle of the normal wintering area for British-ringed birds in the western Mediterranean but, as this is the first ever foreign control of a Blackcap in nearly 50 years of ringing at SML, I think I am entitled to a moment of smug self-satisfaction!

 

Blackcap recoveries map

The map above, cropped from the BTO’s Birdfacts webpages, depicts foreign ringing and recovery locations of Blackcaps encountered in Britain or Ireland. Purple dots indicate locations where birds that have been ringed in Britain or Ireland have been found and Yellow dots indicate ringing locations of birds subsequently found in Britain or Ireland.

An encounter in Spain

I’ve just returned home, after two weeks in sunnier climes, to find a BTO – Ringing Recovery Report sitting in my Inbox. The bird in question was a Blackcap, ringed at SML and controlled in southern Spain. The use of the word “Recovery” started me thinking about the nomenclature employed by British ringers and use of the terms Control, Recovery and Encounter in particular.

My personal view is that a Control is a ringed bird, which has been caught elsewhere by another ringer subsequently and released unharmed to go on its merry way. In the darker reaches of my head I tend to think of a Recovery as relating a bird, which has met either a natural or untimely death and ironically, the one thing it won’t be doing is recovering any time soon!

However, in BTO-speak, a Recovery is a subsequent encounter with a ring, irrespective of whether its owner was alive or dead, re-captured by a ringer, found under a window, brought in by the cat or whether the number was read through a telescope. Note the use of the word Encounter in the previous sentence. This now replaces both Control and Recovery in the latest, on-line version of the BTO’s ringing software – DemOn, where all contacts with a ring from the date of ringing onwards are referred to as Encounters. Grudgingly, I think this makes sense as it encompasses all possibilities by which a ring number could be recorded, and I cannot think of a more suitable alternative, despite scouring a thesaurus.

I’m struggling with the demise of the Control though. It still seems the most appropriate term when a ringed bird is subsequently recaptured elsewhere. There are checks involved. It is a form of control where the ring number, identity, age and sex of a bird are recorded and is not dissimilar from the process at UK airports. I suspect it will be some time before I return from holiday overseas via Passport Encounters or the nice man from Building Encounters comes around to check I have used the correct size beams in my new extension!