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.

Reedbed roost and ruins

With a small break in the weather we finally managed to fit in a CES session at Guwalloe Marsh on Saturday, so while we were there we did a Swallow roost in the reedbed the night before. With well over a thousand Swallows gathering, the birds looked good, the weather looked good and we had our first big Swallow catch of the autumn.

After a long night processing, we ended up with 174 Swallows (inc 14 adults), four Sand Martins and some odds and sods, so a good (if late) start to the hirundine season.

Swallows ready to be processed and put to bed in our roost box

Poor night-time pic, but nice comparison of adult and juvenile Sand Martin

And an even worse photo of them going in the morning!

We followed the roost up by sleeping over by the marsh and then getting up for CES in the morning. The weather was kind for a change and with an extra net the final total of 89 birds was pretty acceptable, including 32 Sedge Warblers and 14 Reed Warblers. Only 69 of these were from standard nets, but this total is our highest ever for Visit 10.

What was apparent was that birds were already fattening up for migration, with several Sedge Warblers carrying lots of fuel: compare the Fat 0 bird weighing 9.1g to the Fat 7 bird weighing 16.7g and you'll get the idea. It was also interesting that it was the adult birds that were the fattest, with the average juvenile weight being 10.8g compared to 13.1g for adults.

Yet another dire photo, this time of a Fat 7 Sedge Warbler

Just to add a bit of culture to the day, we also stopped off to have a nose round the ongoing archaeological dig on the clifftop. The site is a mediaeval settlement and would have been the largest in the Kerrier area, so a bit of a change from the single farm and holiday shop here now! But with some fascinating archaeology on show it was a rather interesting aside...

Apparently these are two walls of an old iron age building

Interrupted Barn Owl brood

A couple of days ago we ringed the last of our first-brood Barn Owls, this time out at a National Trust farm in Penwith. This is a great example of the value of monitoring, with the male of this pair being a first-year bird ringed a few miles up the coast at another National Trust farm. As a young breeding pair, they had a faltering start... Their first nesting attempt was just three eggs, two of which looked like they were never incubated, with the female sitting on a single egg at the front of the box. They soon decided to start over, moving to another box on the farm, laying three eggs in quick succession but then waiting a week to lay a further two! It was presumably these late two that never made it beyond hatching, but three did survive big enough to look like fledging (below being ringed).

With all the first broods now ringed, we can tally up the year and see how it compares to the last few...

	2011	2012	2013	2014	2015
Sites visited	32	34	32	44	40
Unoccupied	2	7	12	12	12
Occupied but no breeding	13	2	7	8	4
Occupied but no breeding	13	2	7	8	4
Failures	0	0	3	0	4
Average brood size (where observed)	3.1	3.1	2.4	3.5	3.5
Number of chicks ringed	33	46	19	63	70

So whilst we checked fewer sites than last year, we saw good rates of occupation and similar clutch and brood sizes to 2014, but managed to ring more chicks than any other year. What was different this year was the high number of failed attempts. Of these, two failed at the egg stage (the young pair above and another where the female was found dead mid-incubation) and two at the chicks stage.

One of the failures saw five large chicks found decapitated in the box. We've seen this once before and presumed it was predation by a Stoat, but we've since heard that adults under stress can sometimes kill their own chicks in this manner, so it was perhaps food stress that caused this particular loss. This happened overnight, being a grisly find for the barn owners when they turned on their nestbox camera in the morning.

But with more boxes being put up and monitored, we hope to have more interesting and enlightening stories to share over the coming years. Thanks as ever to the many landowners who let us into their barns and houses to monitor these birds and in particular to Shaun Boyns at the National Trust for coordinating all of the monitoring in Penwith.

More Storm Petrel news from France

Last month we blogged about the 'rush' of four French-ringed Storm Petrels we caught on one night (see the post here), but we had no such luck in July, but our catch of 75 birds on one night was a bit of a Lizard record! But we've also heard a bit more about the Storm Petrel ringing in France, courtesy of Bernard Cadiou.

He confirmed that the four birds we caught last month were all ringed in 2014 on the Molene archipelago, where he's been running the ringing programme since 1997. In that time he's ringed over 18,000 birds and on just three nights last month they caught 688 birds - all in two nets without a tape-lure! But these are breeding birds and he was able to confirm that most of the birds we are catching in Cornwall are wandering non-breeders, which once settled at a colony will rarely wander far from it. One good example is 2683074, ringed at Lizard on 8th July 2013 and recaught on Banneg in the Molene archipelago just three nights later. Interestingly, it was then caught incubating an egg on the nearby colony of Enez Kreiz in 2014 and was also recaught there by Bernard just yesterday, this time incubating a small chick!

The Molene archipelago lies off the French coast and is home to France's largest breeding population of Storm Petrels. The three main islands are shown below, with the density of breeding birds shown by the coloured grids (or kernel maps for the two right-hand maps).

 

Many thanks to Bernard for the update on their ringing programme on the islands and it certainly inspires us to ring more birds here!

Foreign gulls and legless gulls

The blog has been a bit quiet recently, but that's mainly due to a long overdue holiday in Turkey! But I came back to a bit of a flurry of gull reports, all of which were quite interesting...

The first two were a bit sad, as Herring Gull W:062 appears to have lost a leg! It was seen with both legs intact in amongst the thousand other gulls in Cadgwith Bay in January, so has obviously suffered a mishap since then. It was reported from Swanpool, having been ringed locally in Falmouth in 2014.

We also heard that W:197 from St Ives had been found with a broken wing and broken leg in St Ives, so had to be euthanased by a local vet. Better news came in the form of W:060, originally ringed on Falmouth High Street, which is now also on it's holidays, being seen in France. This is the first foreign sighting of one of our Herring Gulls, so was great news!

We've also only ever had one previous foreign sighting of one of our Great Black-backed Gulls, so receiving two in a week was a surprise. Our only other foreign sighting was L:BF8, ringed in Falmouth and seen in France in October 2014, and it apparently liked France as it was reported from a different site again at the start of May (delayed as reported by letter). Also heading south was L:BJ3, ringed on Mullion Island in 2014 and seen at Lizard Point twice in August 2014. It was seen on Chouet Landfill, Guernsey on 13th July and it's about time one of our birds made it to the Channel Islands.

Apart from this, since the last blog update we've been doing some ringing, so below are a few highlights in the form of pretty pics!

It was another year of low productivity for our Great Black-backed Gulls on Mullion Island, with just nine chicks making it to an old enough age to colour-ringed

Our Kittiwakes have been doing slightly better, with 25 chicks and 15 adults now ringed at Trewavas Head

It's not been such a good year for resightings of French-ringed birds though, with just five birds seen. This bird was ringed at Ponte du Raz, France in 2002 and has been seen at Trewavas Head in 2012 and 2015.

This is also a French bird, ringed as a chick in 2007 and seen for the first time at Trewavas Head this year. Caught inadvertently, we noticed that the colour rings (in particular yellow) were starting to fade so we replaced them with one of our numbered rings.

Away from seabirds, we are also continuing to ring rehabilitated owls at the Screech Owl Sanctuary, these being some of the eight young Tawny Owls ringed recently.