Boardwalk removals

Yesterday we finally managed to get a few people together to start the process of getting some boardwalk into the CES net rides at Gunwalloe. These are sections that were replaced by South West Lake trust at College Reservoir, so we'd offered to 'remove them' for the trust. The down side being that these 4m sections are pretty heavy and cumbersome and required a few strong arms and a trolley for the day.

But finally we managed to get a total of 13 long sections and three short sections out to the road, so part two of the plan will be to borrow a low-loader to get them down to Gunwalloe and then out into the reedbed. Hopefully by next CES season we won't be wading around up to our thighs in thick mud...

A catch up with some colour-ringed regulars

With the weather once again too windy for mist-netting, it was a good time to get out and catch up with a few old colour-ringed friends. One of the most interesting birds is 23D8, which we've blogged about several times before (here and here)! It had been seen yet again coming through the Camel estuary earlier in the autumn, but we hadn't managed to see it yet at Helston Boating Lake. But all in good time, it reappeared this week (22nd), back on its usual rail.

The gulls at the boating lake are always very obliging,
lining up on the railings to have their legs checked
(23D8 is actually the closest bird)

It was then on to Men-aver beach, where there's always a good selection of Med Gulls to look through. But with neap tides refusing to drop, there were only 40 birds here. Three of these had just metal rings, and only one colour-ringed bird. Red PLP2 is a Polish-ringed bird, ringed as a chick in June 2012, and has been seen in March 2013 and March 2014 at Pett Level, Sussex, and later at Ferrybridge, Dorset, in January 2015. This is the first time it's been reported from Cornwall though, so it'll be interesting to see if it stays.

Last but not least, a brief high-tide stop at Devoran produced one of our regular Curlews, again one we've blogged about before (here). 'SA was ringed in The Netherlands in June 2013 and is a regular wintering bird on the estuary.

So if we get the chance, get out and look for some colour-ringed birds of your won, as their histories can get rather addictive!

Busy Nanjizal week and more Skylarks

The last five days have seen daily ringing at Nanjizal, with 493 birds ringed, including 171 Blackcap, 74 Chiffchaff, 22 Firecrest (60 ringed so far this autumn), three more Yellow-browed Warblers (15 so far this month!) and a Little Bunting (one of two present). Also of note were late Reed Warbler, Garden Warbler and the six Siskin (unusual for the site).

Away from the Penwith valley, the rest of us headed out to Predannack (National Trust farm near Mullion) this morning to try for our first Skylarks of the winter. The fields were pretty quiet, so it's perhaps a bit early in the season, and pre-dawn drag-netting saw three birds slip under the net. We were slightly more successful mist-netting, though nine nets did still only produce four birds!

A rather grainy dawn photo, but the colour difference in these birds is hopefully still apparent,
with two rather grey birds (left)

While we were there we took the opportunity to turn the 'Skylark H' into a 'mipit triangle', but the presence of various raptors kept the majority of birds away from the nets. Some hedgerow nets did catch a single Linnet, in amongst a plethora of Dunnocks...

This bird was an interesting aside though, as it had hints of pinky-colour coming through on the breast (suggesting a male), but an incredibly dull, grey head. So we might presume that this was a winter-plumage male, but the moulting wing, and in particular the worn state of the unmoulted inner secondaries (and very dull head), suggested this was an adult part-way through moult. So quite why an adult male Linnet would look quite so shabby is a mystery, but we presume this is a second-year bird, having had a dull first-summer plumage and, so far, a delayed moult of its head feathers.

Note the newly-growing outer primary and the wear on the unmoulted inner secondaries

Lincolnshire-ringed Yellow-browed Warbler

With Yellow-browed Warblers seemingly flooding into the north and east of the country, it was only a matter of time before they made it down to Cornwall in numbers. The last week has seen Yellow-broweds in seemingly every valley and Nanjizal has been no exception. This morning's catch of seven was rather notable though, especially as it included a bird that was already ringed, and not by the group.

One of the seven Yellow-browed Warblers caught at Nanjizal this morning

HPY702 had actually been ringed just seven days previously at Gibraltar Point Bird Observatory in Lincolnshire (over 530km distant). That day there were five ringed at the bird observatory (with an obs record count of 11 in the recording area!). Interestingly, this bird weighed 5.5g when first ringed and a week later it had actually increased in weight to 6.1g.

More Mipits on the marsh

With the forecast suggesting no wind today, we took the opportunity to get the triangle out and catch some more Meadow Pipits at Gunwalloe. Unfortunately it wasn't quite as calm as predicted, but we still managed a respectable 61 pipits, along with a scattering of other species.

Highlight for some was a rather fine adult Moorhen, sexed as a female on biometrics.

Meadow Pipit legs and a Poldark encounter

With the wind dropping for a couple of days we took the opportunity to get the Meadow Pipit triangle up for the first time this autumn. We decided on Gunwalloe, as we could ring in the reedbed at the same time, hoping for some late warbler interest.

Over yesterday and today, we handled 134 birds (123 new and 11 retrap) of which 81 were Meadow Pipits. Not too shabby for so early in the autumn, but there were lots of birds passing, but most chose to settle just outside and around the triangle! But it was a good chance for new recruits to get to grips with a nice species with a useful moult pattern.

If you're lucky, you can see the difference in shape of the primary coverts between this adult bird (top)
and a first-year bird (bottom), with the latter being more pointed at the tip.

We also saw a bewildering aray of colours in these birds, with most typically quite bright olive green, but we also saw some rather brown birds, a very grey bird and also one with very distinct orangey flanks and upper breast (but still just Mipits!). It was unusual that these paler birds also had very pink legs and feet, compared to yellow on the greener birds. More on these later in the autumn...

The reedbed nets also produced a few late warblers (two Sedge, four Reed and five Cettis's, including one ringed as an adult in 2011), Stonechat and a smart Kingfisher. A single extra net also did us proud with a Garden Warbler (first ever caught at Gunwalloe) and two Firecrest (also the first caught here!).

We're not used to sharing the overflow car park at Gunwalloe with anyone, especially not at 6 in the morning, so it was a surprise to find it full of vans, lorries and 30+ cars. A quick chat with the security guards later and we found out this was in fact a day of filming for Poldark. We did invite the main man to grab his scythe and clear a new ride, but he declined...

Online ringing report released

The BTO has recently released the 2014 online ringing report which, for the first time, includes information on nest recording totals and also timing of breeding for many species. The report is freely available on the BTO website and is well worth a look.

Looking just at the figures for Cornwall, the contribution the five-year-old ringing group has made, to nest recording in particular, is clear from the annual totals. Obviously the totals are due to the efforts of many different recorders, but I think group members can take some worthy credit.

The online report also details some of the more interesting movements of ringed birds reported in 2014, and some of the highlights involving Cornwall include:

• Brent Goose from Iceland that stages on Strangford Lough every autumn before wintering at Torpoint

• Storm Petrel ringed in Portugal in June 2013 and recaught at The Lizard in June 2014
• German-ringed Spoonbill seen on Amble Marshes
• Red Kite ringed in the nest in Shropshire in 2013 and seen at Towednack in June 2014
• From Norway, a Kestrel was found dead in Perranporth in November and a colour-ringed Curlew Sandpiper was seen on the Camel estuary in September, just two weeks after ringing
• Woodcock ringed near Coverack in February 2013 was shot in Russia in April 2014

• Black-tailed Godwit colour-ringed in Iceland in July 2010 and seen at Devoran in December 2010, then on the Ouse Washes (Norfolk) in February 2011 and back at Devoran in December 2011, December 2012 and November 2014
• Curlews from Germany (x2) and The Netherlands seen in the county
• Swedish-ringed Turnstone seen in Penzance harbour 

• Colour-ringed Black-headed Gulls seen originating from Poland (4), Denmark (2), The Netherlands and Belgium
• Colour-ringed Mediterranean Gulls seen originating from France (18), Hungary (9), Poland (8), The Netherlands (2), Denmark, Germany and Belgium
• Guillemot ringed on Skomer Island in 1989 and found dead near Bude 25 years later (the national longevity record is 36 years old!)
• Britain's first ever foreign movement of a Chough involved a French-ringed bird seen in Devon in January 2014, Cornwall in February and on the Isles of Scilly in March
• Firecrest ringed in Norfolk in December 2013 and recaught a year later in Penryn and a bird ringed at Stithians in December 2012 recaught in Southampton in October 2014 (recaptures of Firecrest more than a year after ringing are unusual) 

• Sand Martin ringed at Nanjizal in July 2014 was recaught in France a month later (the first movement abroad of a Cornish-ringed bird)
• Unusual autumn movement of a Blackcap ringed at Nanjzal in September 2014 and recaught the next day on Lundy Island, 144km distant
• Danish-ringed Reed Warbler recaught at Nanjizal a month after ringing (only the sixth to be found in the UK) and a Danish-ringed Dunnock died hitting a window in Truro (the first foreign movement ever involving Cornwall and the first Danish-ringed Dunnock found in the UK)
• Chaffinch ringed at the Stithians feeding station in December 2011 and recaught in Norway over two years later in March 2014

Up-country warblers and a lesson in coverts

We recently received details from the BTO of two warblers caught on our penultimate CES ringing session at Gunwalloe on 16th August, both originating from up-country. Reed Warbler D992026 was ringed at Squire's Down, Dorset, on 11th August so had made the take just five days to make the 230km trip down to Cornwall. It almost certainly did it in one go though, and had also had time to put on some pre-migration weight, fattening from 11.2g to 12.4g in those five days.

An altogether different bird was Sedge Warbler Y941821, ringed at Icklesham, Sussex, on 6th August 2013. You then wonder if this bird chose different autumn migration routes as a juvenile and adult, now coming further west, or was this just coincidence.

The only other ringing of late has been a bit of garden ringing for new trainees, but it's always good to catch some instructive birds. The Blue Tit below very nicely shows the contrast between retained juvenile coverts (dull greeny-blue) and moulted adult-type coverts (blue). This bird had moulted all bar one of its greater coverts, the carpal covert and just the smallest alula feather, so see if you can identify them all in the pic!

Think we'll be able to identify this Dunnock without recatching it!

As an aside, I also dropped into Devoran before high-tide in the evening to check the roosting Curlews, to find two colour-ringed birds. We think the below might be a Scottish bird (the single yellow ring was coded BI) and the other bird looked German, but refused to stand on more than one leg in all the time I was sat watching!

Tent-roosting Swallows

Instead of using our large wooden roosting box, last night we used a pop-up tent to roost some Swallows caught in the reedbed at Gunwalloe. The video below shows them being released at dawn, with all birds successfully dry and safe in the roomy tent.

Although the birds came in to roost very late, of the 350 birds present we caught 76, including a recapture of a bird we ringed in the Gunwalloe roost in July 2014 and also a bird ringed on the Isles of Scilly on 20th August, so heading completely the wrong way in autumn! What was equally surprising was that 24 out of the 76 birds caught were adults (32%), compared to 27 out of 284 (10%) ringed at roost earlier this year.

Blyth's Reed Warbler at Nanjizal - a first for Cornwall

In what didn't look like overly-promising weather, the regular autumn mist-netting at Nanjizal continued this morning, producing 93 birds, including five Reed Warblers, four Grasshopper Warblers, three Garden Warblers and what must surely be one of the birds of the autumn in the county! Blyth's Reed Warbler is a long-overdue bird for Cornwall (with a single record from Devon eclipsed by five in Dorset and no fewer than five on the Isles of Scilly), but this didn't detract from the excitement of finding one in a mist-net!

So here are just a few photos and details of the bird, with no doubt more to follow...

Blyth's Reed Warbler will always be a difficult bird to identify in the field, but the rounded wing,
with very short primary projection, can be seen in this bird. Also note the indistinct supercilium,
broad-based bill and the forehead peaking behind the eye.

The identification clincher can be seen in the open wing, with both P3 and P4 (primaries) emarginated:
the narrowing of the outer web of the feather towards the tip of the wing.
On other 'reed' warblers this emargination is only seen on P3.

As if we need to plug the site even more, but any visiting ringers wanting to join the ringing group at Nanjizal can find out more details elsewhere on the blog.

Final CES of the year

This morning finally saw the end of the CES season at Gunwalloe. With the rides getting wetter and wetter, we're not overly sad to see this last session done! The total of 30 birds seems low but was the highest visit 12 total yet and did include a Kingfisher: only the second ever caught at Gunwalloe.

Whilst we missed three visits mid-season due to poor weather, it was still a very productive year, with more birds caught on visits 10, 11 and 12 than any year since we started in 2011. In fact the year total of 366 birds (315 individuals) was the highest since the outstanding 676 in the first year we ran the site.

Catch totals by visit in the five years of CES at Gunwalloe, with 2015 in red

The change in the annual total is primarily driven by catches of Sedge and Reed Warbler, but the table below also shows interesting changes in some species, in particular the crash in Reed Bunting numbers.

	2011	2012	2013	2014	2015
Sedge Warbler	30/85	33/36	13/64	19/41	35/79
Reed Warbler	88/96	60/48	52/63	43/65	42/61
Blue Tit	23/22	14/8	2/16	4/17	13/30
Wren	5/14	0/9	6/4	5/5	7/14
Cetti's Warbler	3/12	3/0	0/1	1/2	2/1
Reed Bunting	8/13	8/3	2/15	3/3	1/1

The fact that just two Reed Buntings were caught on CES this year seems incredible given the double-figure numbers in every other year.

The most notable recaptures this year included two Blackbirds and a Cetti's Warbler ringed in 2011, and two Wrens and a Dunnock ringed in 2013. For the migrants, we retrapped two Sedge Warblers originally ringed in 2013, but the recapture (and presumably survival) rate of Reed Warblers seems higher, with captures of two Reed Warblers ringed in 2011, one ringed in 2012 and nine ringed in 2013.

St Ives Herring Gulls back on the TV

For anyone that missed the original airing of the programme, some of our gull-tracking work that featured on the BBC is available again on iPlayer for the next couple of weeks. The programme 'Nature's Boldest Thieves' looked at the food-snatching behaviour of birds in St Ives and included some work on birds that we colour-ringed and also tracked using GPS data-loggers.

The programme can be viewed on iPlayer here, or just click on the image below.

The bits to look out for on our work are at 14:30, 32:15 and 41:50. The work is still ongoing, so if anyone comes across any of our blue-ringed gulls then do let us know (details on the contacts page).

Why so many adult Sedge Warblers?

We've noticed this month that we seem to have been catching more adult Sedge Warbles than normal, so we thought we'd have a look back through our data from previous years and see if this is correct... So we compared the percentage of adults in our reedbed catches at Marazion/Gunwalloe and also at the migration site at Nanjizal.

We couldn't find a photo of adult/juvenile Sedge Warblers side by side,
so this wing shot of will have to suffice,
but the difference in wear on the flight feathers is obvious,
hence these birds are easy to age

 So the August percentages look like this (with total number of birds caught in brackets)...

	Gunwalloe/Marazion	Nanjizal
2011	10% (375)
2012	16% (125)
2013	8% (198)	7% (215)
2014	12% (87)	8% (657)
2015	24% (128)	15% (907)

From this cursory glance at the data it looks like we were in fact correct, with a much higher percentage of adults in our catch this autumn. Why this might be is a bit of a mystery and it'll be interesting to see how this compares to other sites in the southwest and beyond.

Alderney Stormies and our first foreign Cormorant sighting

In the past we've only shared a single Storm Petrel with the Channel Islands; a bird ringed on Burhou, Alderney in June 2008 that we recaught at The Lizard in August 2013. So it was a pleasant surprise to receive news from the BTO two of our birds from The Lizard had been recaught on Burhou in July. One of these had been ringed in July 2012 and the other was ringed on 16th July this year, recaught there just two nights later.

This got me thinking about the differences between the birds we caught at Porthgwarra in 2011 and the birds we now catch at Lizard (2012-15). The pattern of movements always struck me as being a bit different between the two sites, but is there really anything in it? In 2011 we ringed 190 birds at Porthgwarra (with 6 controls) and since then we've ringed 565 birds at Lizard (with 20 controls). The movements these sessions have generated re shown below:

	From Lizard	To Lizard	From Porthgwarra	To Porthgwarra
France	9	5	4	1
Wales	13	1
Channel Islands	2	1
Ireland			2	1
Isles of Scilly		3		2
Scotland	1			1
Dorset				1
Isle of Man			1
Portugal		1

Some of the differences are interesting, with numerous movements between Porthgwarra and Ireland (Counties Wexford, Sligo and Mayo), but none to/from Lizard. But our ringing at Lizard has shared many birds with Welsh sites, whereas we never traded a Porthgwarra bird with Wales. The obvious explanation for the Welsh movements is the increased ringing activity on the Welsh Islands in recent years, in particular on Skokholm. The table below shows the national ringing totals from the BTO's online ringing report and the big increase in effort in Wales is pretty obvious! But there's no real change in effort in Ireland (the figures here are for the Republic of Ireland), so the fact that none of our Lizard birds have been found there is unusual.

	Wales	Ireland	Scotland	England (non-Cornwall)
2010	87	2144	3997	114
2011	78	1896	5090	170
2012	140	1255	5602	146
2013	553	2682	4312	73

Whilst I was looking at all these recoveries, I thought I'd also look at the length of time between ringing and finding. It is generally thought that birds attracted to 'tapes' are non-breeding, prospecting birds in the first few years of life. This fits with our captures, with most birds being recaught in the next summer or sooner. Obviously there are some very quick movements between sites (we've had one day movement to/from both south Wales and France), but recaptures after more than two years are unusual. In fact, the longest time elapsed was the Burhou-ringed bird mentioned right at the start, recaught five years after ringing.

1 week	5
1 month	10
Same year	9
1 year	16
2 years	5
3 years	2
4 years	1
5 years	1

So whilst a quick look at the data doesn't really answer many questions, it certainly poses a few more questions and we'll just have to keep ringing birds to find the answers!

In other news, we have also just received a sighting of one of our Cormorants in France: our first foreign movement! TBD was ringed on Mullion Island in May (see blog post here) and was seen yesterday on Banneg in the Molene archipelago.

Thanks to Helen Maheo for the photo of TBD on Banneg

Interestingly, this isn't the first Mullion Island Cormorant to be found in France, as there appears to be an old record of a chick ringed on the island in 1969 that was found dead in Loire-Atlantique in 1971. We're not sure who would have ringed this bird, but watch this space for further details...

Early autumn at Nanjizal

August is always an interesting and busy time at Nanjizal, with the first big push of migrant warblers coming through. Where other Cornish sites are catching <100 birds in a session, the valley at Nanjizal regularly produces catches three times this number. Just over the last week, morning catches of 341 and 281 have been dominated by Sedge Warblers (201 on one morning alone), but in amongst them have been a few more interesting species.

Wednesday morning produced an early Melodious Warbler (above) and also Nightingale (below),
actually a much rarer species in the county!

Anyone still stuck for an autumn ringing trip away might want to consider a trip down to Cornwall, so check out some extra info here.