Stormies on the move

Last month saw us able to mist net Storm Petrels down at Porthgwarra on two nights, catching a total of 119 birds. Of these, 113 were unringed, three were ringed by us in previous years and three were already wearing rings from elsewhere:

• ringed on Great Saltee Island (Co Wexford) three days earlier
• ringed on Little Saltee Island (Co Wexford) in July 2022
• ringed at Torre de Hercules in northern Spain in July 2015, although since then it had managed to lose a foot, a surprisingly regular phenomenon in Storm Petrels!

Two birds we ringed on the same night were also recaught 21 days later on Bardsey, also on the same night! Another was then recaught on Lundy Island 29 days later, alongside birds we'd ringed here in July 2016, June 2017 and August 2020, which may well now be recruited as breeding birds on the island.

Hopefully more Stormies to come next week, with a public ringing session likely to be on Monday or Tuesday, so see here for details.

Four nights, four Stormies to Alderney

Over the years we've shared a few Storm Petrels with the Channel Islands and in total 19 Cornish-ringed birds have been recaught there and seven ringed on the islands have been recaught in Cornwall. In fact, just 56 BTO-ringed birds have ever been found on the Channel Islands, so Cornwall provides a fair proportion of these.

This week we received a rush of reports from Burhou, Alderney though, with four of our birds recaught there on consecutive days:

• 15th July - bird originally ringed at Porthgwarra in June 2021
• 16th July - bird ringed at Lizard in July 2012
  
• 17th July - bird ringed at Lizard in June 2016
  
• 18th July - bird ringed at Lizard in June 2019

Whilst some of these may be wandering non-breeding birds, it's interesting to see birds from 2012 and 2016 which are now breeding age birds. Presumably these are nesting on Burhou, which is in fact the only site that Storm Petrels breed on the islands.

Busy seabird weekend

This long weekend has been a busy one, with various group members (and even a visitor from up-country) heading out to all parts of West Cornwall in search of (mostly) seabirds.

We started off with our annual gull-ringing trip over to Mullion Island, which was always going to be an unknown as we were too busy colour-ringing Cormorant chicks on our last visit to count the Great Black-backed Gull nests. We headed over in two kayaks and a dinghy, landing in a quiet cove and heading onto the top of the island. Working our way round we ringed just 10 chicks, but at least another 10 were too big to try to catch. Whilst there, we were also able to photgraph a couple of ringed adults, both of which had been ringed as chicks in 2016 but are now breeding on the island. Interestingly, one (L:CN5) had been ringed as a chick on Looe Island, but has been seen a few times around Lizard and Coverack since.

Next stop was a tour of Barn Owl sites around the Lizard, ringing chicks at 10 sites in total. Several of these later broods had just two chicks, in contrast to those earlier in the season that had three or even four chicks.

Back on the seabird theme, the next day found us Kittiwake ringing at Trewavas Head. Half of the team paddled round from Porthleven while the other half walked in with a ladder from Rinsey. We all reconvened at the cliffs to scramble down and kayak round to the main Kittiwake site. With very few birds successfully breeding, we only colour-ringed eight chicks, but at least this is better than the zero of the last two years. We also took the opportunity to read various colour rings at Trequean zawn and also managed to get photographs of two metal-ringed birds. One of these (ET44236) was ringed on the Isles of Scilly in 1999 and had been seen by us at the engine houses colony in 2018 as well, so is a healthy 22 years old now. The other rewmains a mystery at the moment, with the BTO team looking at the possible options for us of what might be a very old bird!

After an extra couple of owl boxes, we then headed down to Porthgwarra for dusk to set nets for Storm Petrels. This is often the busiest month for Stormies and true to form the first net round before midnight saw 45 birds in the nets, so it was a busy session for everyone. In total we ringed 95 birds, with recaptures of a French-ringed bird and others ringed on the Calf of Man (in August 2020), St David's, Pembrokeshire (in July 2020) and one of our own from Lizard (ringed in July 2020). Talking of Stormies, we also heard from the BTO that a bird we ringed at Lizard in August 2020 was recaught on Alderney, Channel Islands on 10th July.

So al in all a very productiove weekend of seabird ringing, contributing to our ongoing colour-ringing projects for some of these species.

Celtic connection

Lots of Cornwall's seabirds are very connected to our Celtic neighbours, with our gulls, Kittiwakes and Storm Petrels regularly commuting across the Celtic Sea and English Channel. We share a lot of colour-ringed Kittiwakes with the two important breeding sites at Pointe du Raz and Pointe du Van on the Brittany peninsula (a few French birds shown below) and several of our supposedly-urban gulls have been seen on French estuaries and ports.

We had news from BTO British Trust for Ornithology this morning that two of our Storm Petrels ringed in July 2020 at Gwennap Head, Porthgwarra were recaught at Banneg in the Molène archipelago the next night. Banneq is the largest Storm Petrel colony in France, with as many as 1,000 breeding pairs. At 187km, this is probably only a short trip for a Stormie, but it still always amazes me what these tiny birds get up to!

23-hour ringing day!

You know it's summer when you're up before 5am to be out ringing gull chicks and then back home at 4am having been ringing Storm Petrels all night!

This last week has seen various small teams out on rooftops around Falmouth ringing gull chicks, all part of the ever-growing project looking at the behaviour and movements of urban Herring Gulls. So far we've ringed 25 birds on St Mary's School, 20 on Tregnoniggie Industrial Estate, 65 on the university campus roofs in Penryn and various other smaller groups.

Ringing chicks on the roof of Wilko in Falmouth

It's was also full moon last night and perfect weather for some Storm Petrel ringing, so a small team headed down to Gwennap Head, Porthgwarra. As the wind dropped the birds started arriving at the nets and we were set for a busy night!

The final tally was 114 new birds ringed and six birds retrapped that weer already ringed. Three of these were birds we'd ringed previously, one just a month ago at Lizard. Another was a bird we ringed at Porthgwarra in July 2018 that was recaught in North Wales just a week later. Another has a slightly more interesting history. It was ringed at Porthgwarra in June 2015, then recaught on Skokholm Island in July 2015 and in Ceredigion 10 days later. In an almost identical occurence it was recaught again on Skokholm Island in August 2018 and in North Wales nine days later!

Other ringed birds came from Co Mayo (ringed in 2008, so a good age), Skokholm Island in 2018 and also a Spanish-ringed bird. This is only the seventh Spanish-ringed Storm Petrel to be found in the UK, but the fourth at Gwennap Head (after birds in 2008, 2009 and 2017)! Others have been caught at Pendeen (in 2005), Tyne & Wear (in 1992) and two in Scotland.

Welsh Stormies and Falmouth gulls

It's been a while since I've got round to blogging, but then it seems of late we've just been looking at colour-ringed gulls and not much else! But we did receive some interesting reports from BTO recently, involving Storm Petrels recaught at Skokholm Island in south Wales earlier in the year.

The Bird Observatory recaught no fewer than 11 birds ringed by us, including four on just one night (22nd July, when 142 were caught on the island). Of these 11, six had been ringed in 2015 and 2017 at Hot Point, Lizard, with the other six all ringed on 15th July at Gwennap Head, Porthgwarra. This further highlights the link between sites in the English Channel and Irish Sea.

As part of a PhD application for one group member we've also been looking at some of our gull data from Falmouth, so thought we'd share. So across all of our gull sites we've colour-ringed 276 birds, including 199 chicks. Just in Falmouth the figure is 140 birds colour-ringed, of which 85 were chicks. These Falmouth birds have then generated 509 sightings, with 63 of the 140 being seen at least once after ringing. Some of these have only been seen once, but our most reported bird has been seen 60 times now.

Number of resightings of individual birds colour-ringed in Falmouth

Obviously the more sightings we receive the better we understand their behaviours and movements, so if you are a local birder then please keep an eye out for our blue-ringed birds.

Cracking Stormie night and more French Kittiwakes

Same old, same old it seems at this time of year, but when the 'same old' is ringing Barn Owls, Kittiwakes and Storm Petrels then it's not so bad! With over half of our second visits to owl boxes now completed, it looks like the good start to the year hasn't quite come to fruition. Out of the clutches of five or six eggs we were seeing, we seem to be down to broods of just two or three chicks now, which perhaps isn't surprising considering the weather. It might be glorious out there, but the lack of rain means a lack of grass growth and a lack of rodents, so not good for demanding owlets! It's not all been bad news though and we have still seen a few broods of four or five chicks.

Sometimes the adults are just all very relaxed at nest visits,
watching from a handy perch!

Aside from owls, we had our first big Storm Petrel catch of the year at Gwennap Head, Porthgwarra at the weekend. A long busy night saw us ringing 159 birds, also catching six BTO-ringed birds from sites as diverse as Calf of Man, Cape Clear and Hartland Point, Devon. We also caught one French-ringed bird which I have a feeling is an old one, so it'll be interesting to see when that was ringed.

Last but not least, we caught up on some Kittiwake ringing and resighting recently and managed to ring 24 chicks at Trewavas Head. It's a real pity here that most nests are out of reach of a double ladder, but I guess they need to be safe from the Cornish swell! A quick look at Cornish resightings so far in 2018 shows that we've now seen 26 different French-ringed birds this year; eight at Trewavas Head, eight 'loafers' at Lizard, six at Ralph's Cupboard, Portreath and three at Rinsey. This is even more impressive when you consider that to the end of 2016 there had only been 92 reports of French-ringed Kittiwakes in the UK outside of Cornwall! We're sure there are many more out there, so we'll be out again in the week to check...

Busy week of Barn Owls, Kittiwakes and Stormies

We've spent lot of the last week catching up on monitoring and ringing of some of our breeding birds. This has mostly involved Barn Owl boxes and Kittiwakes, but also some new-moon Storm Petrel and urban gull ringing.

So far this year we've ringed 16 adult and 30 nestling Barn Owls, and recaught 10 adults already with rings (including this bird from Suffolk). The birds at Windmill Farm reserve on the Lizard always offer a surprise and this year was no exception. Last year we saw one of the palest chicks we'd ever seen in the brood there and again this year we ringed one very pale chick. But of more interest was the unusual patterning on the wing, with the outer three primaries very different to the rest!

Amongst the other boxes visited was this brood of four chicks which chose not to use the whole of the box, but simply all bundle up on top of each other!

Aside from monitoring the Kittiwakes at Portreath from the cliff-tops, we continued our colour-ringing project at Trewavas Head at the weekend. While two group members kayaked round from Portleven, one climbed in bringing along a ladder to help reach some of the more lofty ledges. It's a good sign when a lot of the birds in the colonies here are already ringed, so we only managed to add another nine adults to our colour-marked population.

OWM-RNN (hatched in France in 2007) with a chick at Trewavas Head, the first time we've seen it breeding. It's been seen at Trewavas Head every year since 2012 but this is its first breeding attempt.

As for Storm Petrels, despite the light wind and early date, we managed to catch an impressive 81 birds at Lizard on one night, including three birds that were already ringed. One of these was from the Channel Islands, with the others both being ringed in 2016 in west Wales. One was ringed on Skokholm Island on 26th July and the other at nearby St David's four days later, providing further proof of the Celtic links of our Stormies.

Injured Peregrines, Portland Stormies and a super-fat Sedge Warbler

We recently received details of some of our ringed birds that had been found elsewhere, both recaptured alive and found dead.

The saddest was the finding of two injured Peregrines, both ringed as chicks in the same nest near Botallack in May. One was found grounded with a broken metacarpal near Helston on 15th August and a second was found the next day near St Just, with a broken humerus and ulna. Both are now receiving veterinary care and we hope they'll recover enough to be released again.

Another interesting set of movements involved three Storm Petrels, all moving between Hot Point, Lizard and Portland Bird Observatory in Dorset (just over 200km). Over the summer we caught two birds originally ringed at Portland Bill (2699028 and 2699030) and have just heard that a bird we ringed on 5th July was recaught there on 19th July. These are the first movements of Stormies between us and Portland, so to have three in a summer is rather coincidental!

Last but not least was a more expected recapture of one of our Reed Warblers on the Isles of Scilly. D791823 was ringed at Marazion Marsh on 8th August 2015 and recaught at Porthellick, St Mary's on 10th June 2016.

Movements of the Peregrines (red), Storm Petrels (blue) and Reed Warbler (green)

On the ringing front, we've been battling the wind and Cornish mizzle to fit in some mist-netting sessions, but have only really managed a couple of Swallow roost catches (totalling 144 birds (and one Sand Martin)) and a couple of mornings in the reedbed, ringing 70 warblers and Reed Buntings. You know migration is well underway though when you catch a Sedge Warbler completely covered in fat. The bird below (excuse the rubbish photo) felt like a tube of butter, being completely covered in stored fat. Considering the fat-free weight of a Sedge Warble can be as little as 9.5g, this bird weighed in at 19.8g!

Not often you get four controls in one net

Last night our numbers were swollen by visitors from up-country, allowing us to us divide our time between nocturnal netting sites on the Lizard. First stop was Gunwalloe where we netted the Swallow roost for the first time, starting off well catching a decent number of warblers and a couple of Reed Buntings (very much lacking in recent years). Numbers of Swallows soon increased, but the roost was rather disrupted by a pack of Starlings also choosing to roost close to the nets, of which we caught a small number. But once these were cleared, Swallows dropped back in and we ended the night with 50 Swallows (along with nine Reed and eight Sedge Warblers).

With most of the team staying to process Swallows, two decamped to Hot Point, Lizard to set nets for Storm Petrels. In amongst a very eerie sea fret, we netted through to 3am, catching 60 birds. The highlight though was one net round which produced five ringed birds (in the same net)! These included birds from Portland Bill (Dorset), Dingle peninsula (Co Kerry), a recapture of a bird we ringed in July 2015 and incredibly two birds carrying rings from the Channel Islands Ringing Scheme.

These birds will almost certainly have been ringed on the small island of Burhou, but we'll have to wait for confirmation. This is rather exceptional though, as to the end of 2015 only 12 Channel Islands ringed Storm Petrels had been recaptured in Britain & Ireland (four of which have unsurprisingly been in Cornwall).

Just for a brief distraction we also caught a bat, which we think was a Pipistrelle... ***UPDATE*** It was apparently a Whiskered Bat!

Full day of seabirds (and some cannibalism)

You know it's seabird time of year when you're heading out ringing for the day and your roof rack looks like this! Add to that a back seat full of paddles, buoyancy aids, drybag, VHF radio and an assortment of rings and colour rings and we were in for a long day...

First port of call was to take two boats over to Mullion Island to try to track down some of the 203 Great Black-backed Gull chicks/eggs we'd counted earlier in the year. Very few birds make it to a ringable size though, but with a record count this year hopes were high. The vegetation was, as ever, challenging and wading through the mallow and sea kale looking for chicks is a laborious job.

Even large chicks are remarkably good at hiding in low vegetation

True to form we found very few birds, which is always a bit depressing; a full sweep of the island found just 13 birds! These were all a good size to ring and colour ring, so it'll be interesting to see where these birds go wandering.

Some birds aren't quite so good at hide-and-seek though

Part of the reason so few birds survive to this stage was evident all around the island though, with at least 16 relatively freshly-dead chicks found. Some of these were pretty well-grown so it does look like predation (or more accurately cannibalism) remains a driver of the low productivity on the island. We're not sure how commonplace this is, but it doesn't seem to be the best strategy for a colonial-nesting bird!

Once we were back over from Mullion, we headed straight round to Praa Sands for the long paddle round to Trewavas Head to the second of our Kittiwake sites (only accessible by kayak). Unfortunately, the swell was way higher than forecast, so it wasn't safe to land and in any case the tide was really high which would have made accessing nest sites rather treacherous! This isn't the easiest of jobs at the best of times, as kayaking round the headlands with a double-ladder strapped to the side of your kayak is tiring to say the least. Makes landing interesting as well and I must admit we did get barrelled by a wave coming back in to Praa Sands.

Last job of the day (after an impromptu ringing group BBQ in the evening sun) was to make the most of a calm, new moon night to get nets up for Storm Petrels. The first net round before midnight produced over 25 birds so we knew we were in for a busy night, but sadly the Cornish mizzle came in at 1am and we had to beat a hasty retreat before the rocks got too slippy. But although we'd not made it to the busiest time of the night the total of 55 new birds was pretty good. It was a bit surprising to find these were all new birds, so we'll just have to go out again on Tuesday night and hope to recatch some ringed birds...

New moon Stormies

The first summer new moon coincided with a period of nice still weather so we had the chance to do some nocturnal netting for Storm Petrels. We headed to Hot Point, Lizard on the last two nights, netting a total of 52 birds. This is more than we've caught so early in the year before so worth the missed sleep!

Close up you can see where these 'tubenoses' get their name from

Most of these were new birds, but we did recatch birds we'd ringed there in June and July last year which is interesting and also a single French-ringed bird. Cornwall really does get the lion's share of French birds with 2/6 birds caught in the UK in 2015 being caught in Cornwall.

We sometimes catch birds with parts of feet or legs missing and the last couple of nights saw a bird missing a whole leg and one just missing the end of its foot. This doesn't seem to hinder them too much though which is lucky!

This is as drastic an amputation as we've seen!

Another Stormie falls prey to a French cat

The weather continues to put a damper on any real mist-netting plans, but there's stil the occasional interesting bird to keep us happy. We were glad to hear last week that a Short-eared Owl that had been picked up in November with a badly-injured wing was almost ready for release, having been cared for by the guys at the Screech Owl Sanctuary. So this female was ringed before release, along with a Barn Owl and two Tawny Owls, so here's hoping we meet them again in happier circumstances!

We also received news today of a couple of our Lizard-ringed Storm Petrels that had been found in France. A bird we ringed on 17th June 2015 was recaught by French ringers just two days later on Ile de Bannec, 173km from Cornwall. Sadly though, a bird ringed in August 2013 was killed by a cat on Ile de Molene, which lies very close to Ile de Bannec. This is the third of our Storm Petrels killed by a cat on the island, so it is rather worrying to think how many other birds are being killed!

We asked Bernard Cadiou in France for some extra info on the problem and he replied: "In 1999 only 18 corpses have been found, but predation increase since 2007 with less than 100 birds killed per year, and since 2013 with about 300 birds killed per year!

The total is now around 1500 petrels killed by cats, mainly wandering prebreeders.

A first campaign of cat control with sterilization was launched in 2011 by the Iroise Natural Marine Park, but unfortunately nothing else was done since then."

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...

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!

Rush of French Stormies

After the success of Storm Petrel ringing the previous night, we headed out to Hot Point again last night, this time in perfect still conditions. With just two of us out, we managed a very respectable 65 birds, but the make up of these made for one of the best nights we've had!

We often deliberate over the ageing of Stormies, so this bird with a single
recently-moulted inner greater covert made us scratch our heads!

64 of these birds were, unsurprisingly, Storm Petrels, which compares well to the 40-50 we normally ring in the whole of June... but what was interesting was some of the recaptures of ringed birds. No less than four of these were French-ringed birds, all ringed above the 'knee'. The latest BTO Online Ringing Report (for 2013) shows just three French-ringed Storm Petrels recaptured in Britain and Ireland, so four on one night is quite notable!

We also recaptured two birds ringed on the Isles of Scilly (in 2011 and 2014) and one of our own birds ringed last year which is interesting. The fact that one of the Scilly birds was ringed as an adult in 2011 contradicts the commonly-held belief that tape-luring only draws in young non-breeding birds...

A final hoorah for the night though was a very smart Manx Shearwater that blundered into one of the nets. We'd had one bounce out of a net the previous evening, but this one flopped in whilst we were extracting Stormies, so managed to get to it before it too bounced. Whilst half-hoping to find it was a ringed bird from one of the west coast breeding sites, it was an interesting training event fitting the overlapped and ellipsed ring!