Out of county cannon-netting and a Dutch Curlew

With the local weather set to continue at 50mph winds and hail showers, we're not going to be doing much until the end of the year, so escaped out of county yesterday for some cannon-netting with Axe Estuary Ringing Group. Unfortunately the birds hadn't read the script and after a long (and cold!) wait we fired on the only birds that had made it across the newly-formed ice sheet in front of the cannon net: two Shelduck and a Moorhen. Just to make matters worse, the day was run as a ringing demonstration, but I hope the visitors were suitably happy with the few birds they got to see!

The assembled masses watching Greg ring his first Shelduck

The group are particularly keen to catch Shelduck as they have a long-term colour-ringing project on these birds, so catching two new birds was better than nothing. Both were juveniles, one male and one female, so it was a good opportunity to compare the sexes side-by-side.

Female Shelduck,sexed by the dull bill and pale flecking on the face

All Shelduck are also ringed with a single coded yellow ring,
remarkably similar to our own Peregrine colour rings!

On our way back we stopped off briefly outside of Truro to check a dead Barn Owl on the road and after battling through brambles (scars to prove it this morning!) and perching on top of the fence along the busy road we could see it wasn't ringed, which saved the need for a death-defying dash to retrieve the bird!

After failing to find any of our colour-ringed gulls in Falmouth, in the fading light I stopped off briefly at Devoran where a roost flock of Curlew produced this rather smart colour-ringed bird. It looks to be from The Netherlands, but we'll have to wait and see.

Thanks to Adrian Bayley for the group photos at Axe Estuary and Greg Wills for the Shelduck photos.

Good old reliable 23D8

With the wind still too gusty for much, all I could manage was a quick walk round the boating lake at Helston yesterday whilst putting off Christmas shopping. Ignoring the temptation of some very catchable Coot and Tufted Duck, the only ringed bird there was the regular 23D8.

Ringed as a chick in Berkshire in 2011, 23D8 spent its first winter on the boating lake in Helston before being seen back in Berkshire in June 2012. It then got into a pattern, being seen on the Camel estuary in early October before moving on to Helston in late October. Last seen at Helston on 1st March, 12 days later it was back in Berkshire for the summer. It made an equally sharp exit, last seen in Berkshire on 2nd July and then again on the Camel estuary 20 days later, before returning to Helston in late October.

I've now seen it several times at the boating lake, so it'll be interesting to see if it's here again all winter. So if you're passing, drop in and have a look for 23D8 and don't forget to report it!

Supermarket sparrows vs a sewage works Yellow-browed

This morning we were tasked with helping to remove a couple of House Sparrows from the back of one of Truro's largest supermarkets. They'd been stuck inside for a couple of months now, so once licences were sorted we were let loose.

It's rather surreal mist-netting in amongst pallets of toilet brush sets, washing powder and nappies, but we were based next to the alcohol section, so not all bad... But once some pallets were moved we could rig up 'Heath Robinson stylee' a single-shelf net at ceiling height, threaded through light fittings, air ducts and water pipes, and a full-height net between the shelving.

Terrible photo of our interesting morning netting site!

Remarkably, with the help of a tape-lure (well MP3-lure) we were eventually able to catch both birds darting through a small gap high up above the shelving. Both were ringed and liberated in a neighbouring garden, so let's hope this is the last we see of them.

Being so efficient at the supermarket, we used the extra couple of hours we had to stick up a few nets at Ponsanooth Sewage Works. There weren't many birds around (apart from a Siberian Chiffchaff, three Firecrest, Green Sandpiper and Woodcock), but one 40' net did catch a little group of warblers, including five Chiffchaffs (all apparently collybita) and a very smart Yellow-browed Warbler; our first of the winter.

These aren't always easy to age, but this bird showed a nice hint of a central crown stripe, which is apparently more frequent in juveniles. This, combined with a rather pointed tail (if a bit fresh-looking), suggested this was a first-winter bird.

Interesting Sibe Chiff at Carnon Downs

The forecast cold weather didn't really materialise, but we were out anyway and with a few birds in the treetops at Carnon Downs sewage works (at least 15 Chiffchaff and two Siberian Chiffchaff) we decided to chance our arm. First bird caught was an unexpected adult Magpie; a new bird for Terry.

Second net round was even better, with the same net producing another adult Magpie and a Grey Wagtail; ANOTHER new bird for a now very chuffed Terry. Amazing what a random 40' net can produce! Interestingly, this second Magpie had a very old retained secondary, looking to be from a good couple of years ago.

Happy faces extracting Magpie and Grey Wagtail

Retained secondary, but from how many years ago?

It was a bit quiet first thing, but as the flies got moving things picked up. We ended up with 40 birds, including 10 Chiffchaffs, two Firecrest (always nice), Grey and Pied Wagtail and a very smart Siberian Chiffchaff. Although the photo doesn't really show it, this was one of the rather grey Bonelli's Warbler lookalikes, which are actually rather uncommon down here. Characteristically for these birds it showed the very long, broad supercilium.

 

Compare this bird with these other two Sibe Chiffs caught in the last couple of weeks. The bird on the left (at Gwithian) shows more green and yellow tones with an obvious, but not overly long, supercilium with a yellow hue in front of the eye, whilst the cold bird on the right (at Ponsanooth) shows no green tones and has a very much reduced supercilium in both width and length.

Stithians ringing demo

After a couple of failed attempts due to poor weather, we finally managed to run a ringing demonstration yesterday morning for Cornwall Bird Watching & Preservation Society (CBWPS) at Stithians Reservoir. We ran this at the feeding station in the southern cut-off to give members a chance to see what we get up to there.

The feeding station was a bit quiet (or the gathered crowd a bit loud) so we weren't busy, but we did manage to show people Blue, Great and Long-tailed Tit, Chaffinch and Greenfinch, Wren, Dunnock, Robin, Blackbird and a few Reed Buntings. We were also able to show people the feeding station and netting area, funded by public donations and the bird watching society.

Thanks to Simon Taylor for the pics and our band of merry helpers for lending a hand.

Another sewage Sibe, and a shiny new reedbed

Another frosty morning meant another look round some sewage works; this time our more regular ones. With very few birds at Carnon Downs we headed straight to Ponsanooth, where there were at least three Siberian Chiffchaff and a mix of other things. We only caught 30 birds, but that did include two very smart Grey Wagtails (dodgy Instagram photo below), a Woodpigeon and a few Chiffs.

One of the Chiffs was a classic Siberian tristis bird and we had the chance to grab a pic along with a more local bird for comparison.

Another interesting bird was a retrap Goldcrest from last winter, so one we know was an adult. Goldcrests are aged on tail shape, with juveniles more pointed than adults, but this bird wasn't the most obvious!

As the catch dried up, we had an hour spare to drop in to Gwennap, where the very amenable guys at South West Water appear to have created us a shiny new reedbed! This is a pretty exciting prospect and it'll be interesting to see how it develops and what birds it attracts.

Even in its current state it had already drawn in two Green Sandpiper, a Snipe and a Water Rail.

Arctic Tern logger update

A while ago we reported the finding of a mystery bird with a GPS data logger (more here), and we have just solved the mystery!

The mystery data logger

The Polish manufacturers of the device were able to download the data and identify the bird as an Estonian-ringed Arctic Tern, exactly as predicted! It was originally ringed on 26th June 2013 on Sorgu island (in red below), on the same day as the bird caught on the Ythan estuary that we mentioned in the original post.

Ringing locations of the Arctic Tern (red) and the three Common Terns (green).
View Cornish terns in a larger map.

This is the first Arctic Tern recovery in Cornwall, and we don't have many of the other tern species either! There are just seven records of British-ringed Sandwich Terns in the county and records of Common Terns ringed in Strathclyde, The Netherlands and Finland (in red above).

Halimodendri, blythi and margelenica - and rare warblers galore

Below Kester writes a quick summary of a reasonable autumn in Penwith:
 
As the mornings get ever more chilly and bird numbers start to dry up, thoughts of packing up the nets at Nanjizal for the winter pop into my head. The late autumn movements of thrushes and finches didn't seem to happen this year, with very low numbers flying over in the first few hours of light. Using a Redwing recording has boosted catches in the last few weeks, but Blackbirds that are usually so numerous in November are altogether missing. Chiffchaff catches remain low, as have Goldcrest and Firecrest, but one warbler caught in higher numbers than usual, mirroring the massive UK arrival, was Yellow-browed Warbler. Up until today, 15 birds have been caught, including an impressive five on 10th November alone! Other birds of note recently were a Dusky Warbler caught on 7th November and a very good candidate for a halimodendri Lesser Whitethroat on 13th November.

Dusky Warbler

Halimodendri Lesser Whitethroat

Tailt moult such as this in first-year halimodendri is actually rather common.

Interestingly, the DNA from this Lesser Whitethroat trapped in early October at Nanijzal came back as being of the race blythi.

Blythi Lesser Whitethroat

And just to add to the mix, going back to 20th October 2000, the bird below was caught. Unfortunately, a feather for DNA analysis doesn't exist, so we may never know what it really was. However, whilst its warm upperparts may suggest blythi, this was a big bird, with a tail length of 65mm, and a very 'blunt' wing. Birds from Mongolia very much resembling this bird have been DNA-tested and identified as being of the race margelenica.

Margelenica Lesser Whitethroat?

Some interesting controls from the autumn were:

• Juvenile Chiffchaff ringed at Nanjizal on 14/7/20113, recaught at Squire's Down (Dorset) on 21/9/2013
• Young male Firecrest ringed on St Agnes (Isles of Scilly) on 21/10/2012, recaught at Nanjizal on 5/10/2013
• Young Sedge Warbler ringed at Nanjizal on 3/9/2013, found dead the next day at St Ives 

So with nets now down for the autumn, some of the notable ringing totals include a top five of:

• Chiffchaff - 701
• Blackcap - 588
• Sedge Warbler - 538
• Chaffinch - 244
• Willow Warbler - 165

impressive totals of:

• Grasshopper Warbler - 54
• Yellow-browed Warbler - 15
• Firecrest - 10

and some rarities:

• Subalpine Warbler - 2
• Wryneck
• Aquatic Warbler
• Marsh Warbler
• Dusky Warbler
• Cirl Bunting

First Siberian Chiff of the winter?

With a hint of cold weather it was time to start poking round sewage works again and this morning we tried a new site for us, Gwithian, where it's nice and easy to net. Six nets in an open rectangle nicely cover the small site and although we only caught 18 birds, 10 of these were Chiffchaffs.

Of the 10 Chiffs, most were rather normal-looking, but one bird did look rather eastern... It's possible this is just a rather bright tristis Siberian Chiffchaff and it certainly called like one when released. But it does have quite a lot of green tones on the mantle and flight feathers, so not the most straightforward.

In comparison, all of the other birds looked more like the one below which was interestingly already ringed. We won't get the details on this bird for a while, but the ring was issued to East Dales Ringing Group in North Yorkshire, so a nice green collybita it is. Supposedly a photograph never lies, but check the difference in plumage tones in these two pics of the same bird: top a fancy DSLR and bottom my iPhone. Not surprisingly the DSLR looks to be a truer reflection of what the bird should look like!

More colour-ringed gulls

The weather is looking a bit more promising for the weekend, so hopefully we'll have some ringing news of our own shortly... But in the absence of calm days, there's always the fall-back of looking at gulls! After misjudging the tide at Hayle estuary yesterday, Copperhouse Creek was my only option, and I was greeted by this rather sleepy-looking Norwegian Black-headed Gull.

J4U4 was ringed as a chick back in 1991 near Stavanger (Norway) so is a very impressive 22 years old! It has been seen at Radipole Lake (Dorset) in February 2005 and was then recaught and colour-ringed as a breeding bird in Norway in April 2012, which then guaranteed a few more sightings. It bred locally in Norway in 2012 and was then not seen until January 2013 when it was on Hayle estuary. It was seen again in February before returning again in October 2013 and still there yesterday, so it'll be interesting to see if it's a regular wintering bird in Cornwall.

J4U4 in breeding plumage in Norway in May 2012

Interestingly, most birds from this Norwegain study head to Scotland and northern England, so a regular Cornish bird is very unusual.

This map shows the finding locations of birds from the Norwegian study,
showing how exceptional J4U4 is in its choice of wintering site.

A quick stop at Stithians Reservoir then also reunited me with a bird we'd ringed in Falmouth over the summer: W:032. It had been seen at the reservoir a couple of times already, but nice to catch up with one of your own birds away from home!

Thanks to Nils Helge Lorentzen for providing the details on the Norwegian bird so quickly, but note that these can now also be reported online here, with details instantly available! Thanks also to Alf Tore Mjøs for letting me steal his photo of J4U4 in full summer attire.

Mauritania Sedge Warbler and a Cormorant caught in the act

We recently received a whole bunch of reports back from BTO of birds we'd either ringed or recaught ourselves. The map below shows the spread of these reports and gives a good overview of where the birds we're ringing/seeing are coming from and going to. The map below shows birds ringed by us found elsewhere (in red) and birds ringed elsewhere recaught/seen by us (in blue), and you can zoom in to see more detail. Clicking on a line will also give you the full details for the movement: species, dates, places...

View Recent recoveries 2013 in a larger map

The furthest movements are a Sedge Warbler ringed at Gunwalloe recaught by French ringers 2400 miles away in Mauritania and a Polish-ringed Mediterranean Gull seen on the Hayle estuary (along with a Channel Islands Herring Gull). The movement to Mauritania is expected as this is where Sedge Warblers go, but is still only thew second from Cornwall to Mauritanis, with fewer than 25 BTO-ringed birds found there!

Other long-distance movements include Storm Petrels in all directions, with two birds to Skokholm Island (expect more from here as ringing has started a fresh here) and birds recaught from the Channel Islands and Co Wexford. We've also now got all the details back on the various colour-ringed Kittiwakes now breeding in Cornwall (more info on these here). These are all from the same French colony, but the interchanges are proving pretty fascinating!

View Recent recoveries 2013 in a larger map

A bit closer to home, a couple more of our colour-ringed Herring Gulls have been seen. Another bird from Falmouth visited Stithians Reservoir and a bird from Rinsey Cliffs was seen on the beach at Marazion. These birds all have a blue ring with code W:000 to W:999 so keep an eye out for these around the coast or at any gatherings of gulls. Another of our colour-ringed birds reported was a Cormorant caught in netting whilst stealing fish from an inland fishery, but was happily untangled and released unharmed. Wonder if it's learnt its lesson??

We don't have a photo of Cormorant TAH caught at the fish farm,
but here's TAB also ringed on Mullion Island

One final interesting movement is a Sedge Warbler ringed at Nanjizal and then recaught five days later at Gunwalloe, almost directly due east. We've also had recent reports of some of our Sedge Warblers moving north in autumn, so I wonder if these are actually heading out of the country somewhere further east and not directly or through the Isles of Scilly as expected...

Welsh wanderer

Although not strictly a West Cornwall Ringing Group bird, Great Black-backed Gull L:AU8 has been seen on our patch a couple of times...

It was ringed as a chick on St George's Island, Looe, in 2011 and was first seen on Hayle estuary in October 2011. It wasn't reported again until 24th September when it was on Skokholm Island, Pembrokeshire, and then the shockingly bad iPhone-scoped photo below (mine...) came from Copperhouse Creek, Hayle, just 26 days later (10th October).

Presumably this bird won't breed for another couple of years and will continue to wander, so where will it turn up next? Hayle is a great place to look for colour-ringed gulls and if you're lucky enough to find one then details of project coordinators can be found on the cr-birding website.

Nest recording in 2013

We've been a bit late submitting our nest recording data for this year, but having finally sorted all the final outcome codes and monthly effort recording, I finally sent it all off to BTO this afternoon (see more on the BTO Nest Record Scheme here). The total of  144 nest records was pretty good, although admittedly a fair few of these were single-visit seabird records...

All our records of Great Black-backs and Cormorants are from Mullion Island

The top five species were Blue Tit (43), Cormorant (24), Shag (18), Great Black-backed Gull (16) and Barn Owl (12). Of these, where we had multiple visits at the right time of year, we found average clutch sizes of 7.2 for Blue Tit, 2.4 for Shag and 3.3 for Barn Owl (compared to 3.6 last year). Despite very low occupancy of Barn Owl sites this year, the average clutch size compared well to the 3.6 recorded last year, but the average brood size of 1.8 compared pretty badly to the 3.0 in 2012.

Also doing badly were Great Black-backed Gulls. On our first visit to Mullion Island we counted well over 100 chicks and eggs, but later visits (theoretically to colour-ring chicks) found only a handful of survivors, with perhaps as few as three or four birds fledging! What happened to the others is a worrying mystery.

Some of the mystery missing Great Black-back chicks

Conspicuous by its absence from the top five this year is Kittiwake. The Rinsey colony failed completely, with just six active nests all failing at the egg stage, which compares badly to the 44 active nests in 2012 (36% of which failed).

The full list of nest records submitted is below:

Blue Tit	43		Dipper	2
Cormorant	24		Jackdaw	2
Shag	18		Blackbird	1
Great Black-backed Gull	16		Nuthatch	1
Barn Owl	12		Stock Dove	1
Herring Gull	9		Swallow	1
Kittiwake	6		Tawny Owl	1
Great Tit	6		Wren	1

Not one of mine, but this brood of Robins in a fertiliser bag
at the Lost Gardens of Heligan couldn't be left out

And perhaps not surprisingly, this nestbox in Lizard wasn't used...

Black 27M is a French first

A good stormy Cornish day meant that the only thing to do (other than work!) was chase a few colour-ringed gulls. Having been evaded by a French-ringed Med Gull at Men-Aver beach last week I thought I'd have another look this afternoon. Just after low tide on a good day, up to 60 Med Gulls congregate on the 'reef' here, but today wasn't a good day, with a paltry three present, none of which were colour-ringed.

But the larid redeemed themselves with a Great Black-backed Gull sporting an unfamiliar black colour ring. OK, so you can't see its legs in this dodgy iPhone-scoped photo, so you'll have to believe me that it was 27M, a bird ringed as a chick in Normandy in 2013. We don't get many foreign-ringed Geebs in Cornwall, with records of just six; four from the Channel Islands and two from Norway, so this French bird is a bit of a first.

Finch frenzy and a moult muddle

The last few days has seen a continued influx of autumn migrants into The Lizard and a couple of calm mornings has allowed us to capitalise on this. In my relatively small garden (below, with the school playing field behind), with just one 30' net, we've been busy catching Goldfinches coming to nyger seed and have caught over 140 in the last two days. Add to this a few Greenfinch, Starling, Chaffinch and single Siskin and Pied Wagtail and it's been busy!

Most of the Goldfinches have been young birds (and oddly more females than males), distinctive with their pointed tails, juvenile primary coverts and unmoulted greater coverts (although most had moulted them all). A surprising number were still in their first juvenile plumage as well, which seems a bit late. Most of the (presumed) adults caught were just finishing primary moult, with just two already done. There were then the odd one or two birds where ageing wasn't quite so simple.

The bird below was just finishing primary moult, with just the outer two primaries (including the vestigial outer one) to go. But is the unmoulted primary here really old enough? If this was a moulting adult, then this primary would have been grown as part of the bird's main moult a year ago. The other option is that this is a juvenile bird (from an early brood perhaps) undergoing a complete moult, in which case this primary would have been grown in the nest a few months ago.

So how can we decide on the age of this feather? Comparing it to known juveniles is one option... The bird below is a known juvenile, with a 'good' tail and dull primary coverts, and appears to show primaries with a similar amount of wear to our mystery bird.

Another juvenile (below) shows even browner primaries though, despite the poor quality photograph - iPhones don't do macro! So if our mystery bird has a fresher unmoulted primary than this juvenile, then it too must be a juvenile right?

Note as well on this juvenile has also moulted some primaries, but not all of them. The outer three (ignoring the vestigial outer feather) appear rather brown with worn tips, whereas the inner feathers are much fresher, darker-centred, with brighter yellow outer webs and with more obvious unworn white tips.

To be sure we'd really need to compare to a known adult in active moult and see how worn the unmoulted outer primaries really are at this time of year. But this does indeed look like a juvenile undergoing a complete moult, which means that it's rather unsafe to assume that other birds finishing primary moult are adults...