Reedbeds, Dippers and an interesting Barn Owl movement

With summer vaguely arriving in Cornwall, this week saw us dusting off the mist nets to start the 2015 CES (Constant Effort Site) season at Gunwalloe. This is now the fifth year we've run the scheme, adding to the BTO's national dataset monitoring the breeding performance of a range of species.

The so-called 'dry ride' at Gunwalloe

The first few visits of the season are always a bit quiet, as we are mostly targeting reedbed migrants here, yet to arrive in big numbers. Those that have arrived are busy setting up territory and not flying round the reedbed, so the catch of just 16 birds was expected. This was mostly Reed and Sedge Warblers though, including two of the former ringed in 2013. We also retrapped Reed Warbler Y101100, originally ringed as an adult at Gunwalloe in June 2011 and retrapped seven times since on site. This is even more impressive when you consider this bird has now crossed the Sahara desert at least 10 times!

We are now also just starting the main nestbox checks of the year, with the first chicks ringed this week in the form of our usual Dippers in Idless Woods. We probably missed one brood that fledged quite early, but the second box had two fat chicks (from four eggs) at the perfect size for ringing.

Two Dipper chicks tucked up in their not-so-cosy-looking nest

Last but far from least was another morning spent doing Barn Owl box checks, this time in the west of the county with National Trust ranger Shaun Boyns. Once again birds seemed to be doing pretty well down here, with two pairs already with chicks hatched! One interesting National Trust story was the male in the box at Trevean (an NT farm), which the nestbox camera had shown was ringed. We presumed it was a bird from one of our sites locally, but was in fact a bird that we'd ringed as a chick at Treveal (an NT farm) in 2014. At 8km, this isn't the longest movement we've seen, but it's great to see a bird breeding in its first year, and one we know very well indeed.

GR80993 in his new home at Trevean

GR80993 and two siblings when ringed at Treveal in 2014 (we're not sure who's who though!)

Next stop are Cormorant chicks on Mullion Island tomorrow and hopefully retrieving the remaining GPS data-loggers from our Herring Gulls in St Ives...

Early spring at Nanjizal - Little Bunting and Hoopoes (yes plural)!

Early spring has always been a bit hit and miss at Nanjizal. With the site being so exposed to the winter weather, the vegetation growth usually lags behind sites just inland, so we presume that early migrants overfly the rather wintery-looking site. Like a lot of other sites in the southwest, early spring is dominated by Willow Warbler and Chiffchaff, but constant northwesterly winds are never good news, and this year seems to be no exception. When the wind does drop, birds seem to find themselves further east; perfect for Portland Bill!

Over the last winter, the surrounding fields at Nanjizal held good numbers of Reed Bunting and the first ringing session of the season targetting them (on 5th March) saw a nice surprise in the form of a Little Bunting. It could well have been overlooked during the winter months, but was light, with little in the way of fat, so may have actually been on the move back north.

Chiffchaff numbers were very low in March and only one Willow Warbler was ringed, but things improved in April following a period of good weather. Despite there being no large numbers of Willow Warbler or Chiffchaff present, the vegetation is improving and Blackcap are finding the flowering Blackthorn to their liking, with the first Grasshopper Warbler and Whitethroat also now in.

Highlight of the spring so far came at the start of April though, with three Hoopoes frequenting rough, pony-grazed pasture next to the site. On consecutive days, a male and female were caught, giving a great opportunity to compare plumage details on these two second-year birds.

We won't necessarily tell you which is which of these two birds, but if you'd like to have a go at sexing them yourself then there's a great online resource here:

Rinsey Kittiwakes

Making the most of low tides and fine weather, two of the group clambered down to the Kittiwake colony at Trewavas Head this afternoon to have a quick check for colour-ringed birds. The rather inaccessible site had the usual 35 pairs looking to occupy nest sites and the short tidal window gave us the chance to sit and look through the birds present.

In the end we managed to read rings on four of our own colour-ringed birds (all ringed here in 2013) and two French birds.

WWN,OWM was ringed as a chick in France in 2007 and was seen at Rinsey Cliffs
three times in both 2012 and 2014, but has now moved to Trewavas Head

OWM,RNN was also ringed as a chick in France in 2007
and has been seen on and off at Trewavas Head since 2012

Interestingly, one of our own birds back at the colony today was also photographed at sea back in July 2014 - see blog post here.

CT (right) back at Trewavas Head today

CT at sea off Longstones Lighthouse in July 2014

Easter eggs

It only seems right that over Easter weekend we should post about all things egg... Whilst the season has only really just begun, we already have a few species sitting on eggs. The first to lay were Mullion Island Cormorants, closely followed by a few early Shag nests at Rinsey Cliffs, the latter site now having 12 birds sitting. Shags being Shags, some of these won't be sitting on eggs, but at least seven birds are sitting on full clutches of three eggs.

Our first nestbox birds are also on eggs as well: not surprisingly Dippers in Idless Woods. One box just contained a lined nest but the second box had a presumably as yet incomplete clutch of three eggs, nicely covered with beech leaves (I think!). This is a little later than last year, when they had a full clutch by 27th March, but earlier than 2013 when the same date say just two eggs laid.

Idless Woods Dipper nest

Mullion Island Cormorants on the move

Never good to find that the morning you're off over to your seabird island there's frost all over your kayak! But thankfully the good old Cornish sun came out and warmed the day up pretty quickly.

So three of the group paddled out to Mullion Island (with an intrepid swimmer in tow), primarily to check how the Cormorants were doing. With our first Shag egg being a month earlier than in 2014, we'd half expected the Cormorants to be hatching by now. But what greeted us was a little bit disappointing...

The same area of the island in 2014, with numerous raised nest sites

The 'usual' (for the last two years at least) site was unoccupied, which had us worried momentarily, until we noticed where the birds had moved to for the summer! A small number of birds had moved onto the east-facing cliff edge, but most birds had moved right out onto the steepest cliff-edge along the western side of the island.

The white splats are a good indication of where the colony has now moved to

So sadly it looks like our Cormorant colour-ringing will be a bit limited this year, but at least it'll be easier to round up Great Black-backed Gull chicks later in the year.

And yes, whilst it was a nice and sunny day up top, our swimmer confirmed that the sea was still rather cold...

2015 breeding season is upon us

Despite being a bit restricted in ringing activity of late, a spare sunny day seemed the ideal opportunity to nip back to Rinsey to check out the seabird situation. Following last year's late season, I was only really expecting a few early-returning Kittiwakes, but was pleasantly surprised.

Only a dozen Kittiwakes were were back on the cliffs, but these did include CA, an adult bird we ringed last summer, and also a French-ringed bird, but this headed out to sea before I could get a 'scope on it to get the full combination of colour rings.

CA (top right) back on its ledge

But more pleasing was our first Shag egg of the season, with one pair having at least one, possibly two, eggs (just about visible below). This is a full month earlier than last year, but about the same time as in 2013, so here's hoping it'll be a return to successful breeding seasons...

Gull-fest at Coverack

The last few days have seen increasing numbers of gulls following fishing boats into Coverack harbour. Whilst the highlight for many are the four (or more) Glaucous Gulls there, members of the ringing group have been focusing more on reading colour rings.

As many as a thousand gulls are in the bay at any one time

Whilst birders focus on the first-winter Glaucous Gull (left), others are more interested in colour-ringed birds, such as this yellow-ringed Great Black-backed Gull from Guernsey (right)

Over the last few days, we've managed to read rings on 18 different birds, including birds from France, Guernsey (4), Skokholm, Denny Island in the Bristol Channel, Portland, Looe Island (5) and Falmouth (5).

W047 was ringed in Falmouth and is usually seen at Helston Boating Lake. It was seen there as recently as 21st before taking up residence at Coverack from 24th.

DAC was ringed on Denny Island in the Bristol Channel in 2013. It has since been seen on the Camel Estuary (21/12/13), Cadgwith (26/1/14), Chew Valley Lake (11/8/14) and Blagdon Lake (15/10/14), before turning up at Coverack this week.

Red W:043 is from Skokholm Island in south Wales, and was seen sat close to blue W:043 which is one of our own Herring Gulls from Falmouth!

Just to keep everyone happy, here's a couple of photos of Glaucous Gulls, showing a very bleached bird and a very fresh one.

St Ives gulls on the BBC

We've blogged a bit about some of the gull work we've been involved with in St Ives (here, here and here), but the BBC show that funded this was eventually broadcast earlier this evening on BBC1. If you're quick you can catch it on iPlayer for the next few days (available here).

The programme is worth a watch, but for those pressed for time, the amusing bits to look out for are us catching a few birds from 14:40 and a hint at some of the GPS logger results from 32:20, although they gloss over the fact that since the summer we've accumulated over 35 million data points from these birds!

Dutch-ringed Chiffchaff (and 28 others)

With a carload of the group out of county cannon-netting ducks and waders with the Axe Estuary Ringing Group, I was on my own at Gwennap sewage works today. With just two nets, a couple of hours produced a very respectable 41 birds, including 29 Chiffchaffs!

The highlight was the bird below, which I thought was a British control (AAH203 - actually a Wren ringed in Cumbria in 2003) until I noticed the ring address which read 'ARNHEM HOLLAND'. Dutch-ringed Chiffchaffs aren't very regular in the UK, with fewer than 30 previous records. This isn't the first to be found in Cornwall though, as one was retrapped at Brew, near Sennen, in May 2007. Oddly this bird had been ringed just nine days previosuly in The Netherlands, so a very odd movement!

Another interesting bird was this Siberian Chiffchaff. Not the classic bird, lacking all olive and yellow tones, but a more subtle type. But it still showed very washed out plumage tones, along with a slightly flaring supercilium behind the eye and jet black legs.

Bit of sunny weather on a cold day was all it took to
bring out the insects and hence the birds

The 'bycatch' of the day wasn't too shabby either, including one of two Yellow-browed Warblers and one of three Firecrest present at the site.

Winter wanderings of a St Ives gull

We've recently been able to look at some of the data from the GPS data-loggers on the three gulls in St Ives and one of these in particular is quite interesting. Logger 4036 (colour ring Blue W:181) was a breeding male originally ringed on the roof of the Co-op in St Ives. Over November-December 2014 it took a couple of trips out to the north, visiting Lundy Island for an overnight stop on one date. A second trip then took it out to both Great and Little Saltee Islands, a brief visit to some fields near Duncormick (as far as 240km from St Ives) and then a visit to Hook Head.

What is also interesting is the time it spent at sea on its return, with a cluster of points in the Celtic Sea. It is possible that it was either following fishing boats feeding or a resting bird 'riding the tide'.

W:181 has always been a very pelagic bird, and the track below (in yellow) shows some of its movements during the breeding season, again wandering out into the Celtic Sea.

Many thanks to Peter Rock for getting to grips with the data and producing the maps here.

Reading Chiffchaff and Med Gull rings

The year seems to have started as it ended, with some pretty windy weather forecast... So looks like we won't be netting any time soon, but that doesn't stop us getting out and reading some rings. Photographer Tony Mills did incredibly well to get enough detail on a Chiffchaff ring at Sandy Cove, Newlyn, to get the whole number: HHB515. This was a bird ringed at Nanjizal, Land's End, on 20th November, so whilst only 11km away (as the Chiff flies), it's interesting to see how these birds move around during the winter.

More standard fare came from Men-aver beach on the Helford, with a good gathering of gulls producing three colour-ringed birds. These were two Mediterranean Gulls we've seen before this winter (Green RS92 from France and White 3P71 from Denmark) and one of our own Great Black-backed Gulls from Falmouth. L:BF6 was ringed as a chick on the roof of the Falmouth Marine School in 2013 and this is the first time we've seen it since. This is the second of the three siblings to be seen, following a bird in France in October.

Last few Chiffchaff of the year

Barring calm enough winds tomorrow to net a few garden birds, today saw the last mist-netting of the year for the group. A morning start at The Lizard caught a few Goldfinch, Greenfinch and House Sparrow, and we then headed on to Gwennap Sewage Works. The cold start to the day had brought reasonable numbers of birds into the works, but the afternoon sun meant the insects were up in the trees, so most of the 20 Chiffchaff and three Siberian Chiffchaff there were too high to catch. But enough were milling round the site that we still managed to ring seven collybita Chiffchaff and one tristis Siberian Chiffchaff.

The tristis Chiffchaff (left) stands out against the 'standard' bird on the right, lacking olive-green or yellow tones on the plumage. Seems odd, but tristis Chiffs always seem to fluff up...

Travelling between the two sites today, we stopped off to check a dead bird on the road for rings, but by the time we'd turned round it had miraculously recovered and was stood in the middle of the road! After narrowly being missed by a passing car, we managed to scoop up a stunned adult Water Rail and take it with us. After a short while in the bag we normally store our nets in (and a nice portion of Sardines we bought for it) it recovered and was quite feisty. So it was duly ringed and released into the more salubrious setting of the new reedbed at Gwennap.

Stithians Chaffinch in Norway and even more Welsh Stormies!

Our last blog post highlighted a few interesting recoveries received from the BTO, and with only a very slight alteration to the theme (this time "Autumn migrants going the right way and more Welsh Stormies"), this post highlights more recoveries received today. Normally the crown would be taken by the reports of three more Lizard-ringed Storm Petrels recaught in south Wales, but instead of the usual reports from Skokholm Island, these came from nearby Skomer Island. Two of these birds were ringed on The Lizard in 2013, recaught on 28th and 29th July 2014, but 2683255 was more interesting. It was ringed on The Lizard on 30th June 2014, before being recaught on Skomer Island at 23:25 on 25th July. Not satisfied with this, it was then recaught an hour and a half later (01:00 on 26th July) on Skokholm Island, 3-4km from Skomer. The chances of this must be rather slim, but it'll be fascinating to see if this bird is caught again in future years.

But this time round, the most interesting recovery was of a lowly Stithians Chaffinch, ringed as an adult way back in December 2011. We've often wondered how far these birds came to winter at Stithians and presume that they'd be local SW birds relocating, so this report from southern Norway was amazing! Y397543 was recaught near Høvåg on 25th March 2014, presumably on return migration to somewhere else in Scandinavia.

This is just the second Cornish-ringed Chaffinch to be found in Norway (following one in 1977), but four have made it to Sweden.

Last up was another northward-bound migrant, but this time a Sparrowhawk ringed in a Lizard garden on 6th September and sadly found dead on the road in Falmouth a month later.

Autumn migrants going the wrong way and more Welsh Stormies

We've just received a whole batch of reports back from the BTO detailing some movements of birds to and from the group area. There were rather a lot of local movements, but here are some of the highlights.

 

Our great run of Storm Petrel movements continues (see the first few here), with yet more movements to and from Wales. This time we received details of four birds ringed at The Lizard that were recaught in Pembrokeshire, on Skokholm Island and at Wooltack Point. Two of these were birds ringed in 2012 and 2013, but the others were quite quick same-year movements, at 38 days, 26 days and 20 days. In fact, all of these last three were ringed on the same date (30th June), the same date we also caught a Portuguese-ringed bird.

The Portuguese-ringed Stormie caught back in June

We then just had one Storm Petrel movement he other way, from Skokholm to The Lizard (194km), but in managed this in just one day! It was ringed at 00:40 on 24th July and recaught down at The Lizard at 00:30 on 25th July.

 

Two rather more unusual reports came from Nanjizal, with migrants moving north in the late summer/autumn. A Sedge Warbler ringed on 21st August was recaught 250km away in Dorset seven days later (so moving northeast) and even more bizarrely a juvenile Sand Martin ringed on 10th July was recaught nearly 500km away in West Yorkshire six days later! This again is a very quick northeasterly movement and seems most odd...

Six-day movement of Sand Martin Z118605

Lesson in fault bars

In what turned out to be a quiet morning at Predannack, I thought we'd just post up a pic of this rather obvious set of fault bars on a Chaffinch.

Fault bars are areas of weakness where growing feathers have been compromised by poor weather, food shortage etc, and are normally most obvious on tail feathers. This can happen at any age, but the key thing to remember is that juveniles grow their main flight feathers (including tail) at the same time (in the nest), whereas adults will moult them sequentially. So although birds of any age can show fault bars, the fact that on this bird the distinct pattern of fault bars is the same distance from the tip of all the tail feathers indicates these were all grown at the same time; ie this is a juvenile bird.