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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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!

The 2017 Ringing Report

2017 Ringing Report

I have just finished preparing a ringing report for SML for 2017, partly because Natural England have sent me a copy of their rules relating to bird ringing on SSSI’s, which says a report should be submitted to them annually, but principally because I think that data is of no value unless it is in the public domain. Copies have been sent to Natural England and to Devon Birds for the Harrier.

Chris Townend’s assessment of the bird reserves owned or managed by Devon Birds in 2015 recommended that: “All reserves should have realistic, species specific targets for birds breeding, wintering or on passage. Measuring the success of such targets can only be carried out through regular and accurate monitoring.” The current SML management plan also highlights areas where contemporary data on the flora and fauna of the reserve are inadequate or lacking and the need to address this shortcoming before future changes and the impact of habitat improvements can be assessed. With this lack of data in mind, ringing continued throughout the breeding season in 2017.

Historically the principal focus at SML has been on ringing migrant birds during spring and autumn passage but, as the migratory routes of most of the species there are already well understood, the focus has now shifted to more demographic based studies. For the first time, in recent years, ringing took place in every month and continued throughout the summer. This will enable changes in population, survival and productivity rates between years to be monitored in the future at SML.

Overall it was a productive year with significant improvements to the ringing infrastructure leading to a total of 2,137 birds processed, including nearly 1,200 warblers, and the data collected will form the baseline for future comparisons. You can read the full report here: Annual Ringing Reports

Sunday 8th April 2018

Arum sp

A windless morning with a thin layer of high cloud saw me back at SML just after dawn. It was a little bit warmer and a little bit busier today, although still best described as slow and steady. 32 birds were trapped of which 21 were new including 14 Chiffchaff, 5 Blackcap and 3 Willow Warbler. The Spotted Crake remained on site, calling just twice at 07:30 and 09:15. It has been completely elusive, despite the best efforts of numbers of hopeful observers, and isn’t responding to tape lures any more. I did get good views of a Water Rail in the same area of reedbed though as a consolation. The whole reserve remains exceptionally wet and the fact there are still rails present and they have ceased calling and gone into stealth mode reinforces my belief that there may be several pairs attempting to breed this year.

On a non-bird note, I was tipped off by a visitor last Sunday that there was an unusual flower growing in the upper Ley. Risking life and limb and nearly parting company with my wellies in the process, I managed wade through a particularly wet and overgrown swamp to secure the photo above, which I think is Arum italicum, based on the colour of the spadix and the lack of purple around the margin of the cowl. Separation from the native Lords-and-ladies or Cuckoo Pint, Arum maculatum is not easy for a non-botanist with limited reference books but, either way, it will be a new species for the reserve’s plant list!

Thursday 5th April 2018

After another unproductive session on the 26th March, which certainly wasn’t worth blogging about, with just three new Chiffchaffs ringed, and with a forecast of a clear skies and no wind I was anticipating a decent day at SML and it started well. Arriving at 07:00, there was still a thin layer of frost on the ground and on the mist net poles, and I made my way to Marsh Ride to erect the nets when I was amazed to hear the unmistakeable whiplash call of a Spotted Crake just a few metres away from me. Despite my best efforts I couldn’t see the bird although it responded well to my attempts to imitate its call. It called again briefly a couple of hours later and that was it. I am reliably informed that this is the first spring record for the area.

On the ringing side, things weren’t exactly hectic with 19 birds trapped of which 12 were new including 4 Chiffchaff, 3 Willow Warbler and 1 Goldcrest. Re-traps included a male Cetti’s Warbler of unknown origin and female ringed as a 1st year bird at SML in 2016. This is good news as Cetti’s have been very quiet here for the last couple of years and it’s nice to know that a pair is present at the start of the breeding season.

Tuesday 13th March 2018

Crest Ride 1

Crest Ride, March 2018

A brief ridge of high pressure gave me a weather window to get some nets up after what seems like an endless procession of wind, rain and snow so far this year. In the event, it was hardly worth the effort with just six new birds and three recaptures. All of the wintering Chiffchaffs and Crests have either departed or perished during the snow and sub-zero temperatures at the beginning of month. I have already received details of a Goldcrest found dead at the neighbouring Mill Farm on 27th February, when overnight temperatures fell to -4oC and I’m sure many others will have succumbed in the days that followed when the South Hams was covered in snow.

On the brighter side, one of the recaptures was a Chiffchaff returning for the breeding season. Originally ringed in April 2016, this is the first returning Chiff to be caught this year. At least three other males were singing strongly in the hedgerows around the ringing area. Unusually, at least four Water Rails were calling between the sewage treatment plant and Marsh Ride. Wintering birds have normally departed by now and I am speculating whether this year’s unusually high water table has encouraged some birds to stay to breed. Water Rails have only been proven to breed at SML on one occasion (1989) but the species is occasionally heard during the spring and summer months. Whether these are breeding birds or summering non-breeders is unknown. Water Rails normally start incubating during the last week of March in the south of England so I’ll be keeping a lookout for any sign of breeding activity.

Friday 26th January 2018

JPA984 tristis

The first of three Siberian Chiffchaffs trapped on 26th January 2018

At last, a dry day with winds, which were low enough to get some nets up. In fact, at times in mid-morning it felt positively balmy. The sunny periods were enough to produce swarms of midges, whirling about in mating dances on the leeward sides of taller trees and a north-westerly breeze drifted them towards the net ride beside the sewage treatment plant. Things were looking good for decent numbers of Chiffchaffs. These midges are a major component of their winter diet, often turning their droppings black, when the midges are swarming. When the sun goes in the midges disappear and the warblers disperse making them harder to trap.

JPA971 tristis

The second Siberian Chiffchaff

In the event, the morning’s tally of 47 birds included 30 Chiffchaffs, 4 Firecrests and 2 Goldcrests. Three of the Chiffchaffs showed all of the characteristics of tristis and two of them obligingly gave the characteristic short “peep” call when released.JPA 978 tristis

 

Wednesday 10th January 2018

A lovely day but not many birds.  Just 14 new birds were ringed including: 5 Chiffchaff, 3 Firecrest, 2 Goldcrest and 1 Reed Bunting.

Also on site: another 20+ Chiffchaff, 1 Siberian Chiffchaff, 2 Redwing, 5 Water Rail, 1 Sparrowhawk, 1 Tawny Owl and 1 Great Spotted Woodpecker. There were 3 Hares in the middle of the field to the south of the reedbed and a weasel ran across the footpath by the sewage treatment works.