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.

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!

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...