Barn Owl 2022 update

It's been a strange summer for lots of our regular projects, with freak weather, bird flu and remnants of Covid still making life difficult. Some of our birds have fared particularly badly, with Kittiwake reduced to just one successful sitre across Cornwall, a crying shame.

Our Barn Owl monitoring continued pretty much unaffected though and despite the drought, birds actually seemed to do OK. The project continued to grow and we personally visited over 100 boxes for the first time, which is no mean feat. Despite clutch sizes being nothing special, birds survived quite well and were about average.

	2012	2013	2014	2015	2016	2017	2018	2019	2020	2021	2022
Sites visited	34	32	44	41	47	64	85	87	106	93	112
Unoccupied	7	12	11	11	12	23	34	36	43	35	34
Occupied, no breeding	2	7	7	7	8	5	4	3	4	5	4
Average clutch size (where observed)	4.1	3.6	4.6	4.6	4.6	5.3	5.2	4.7	4.6	4.5	4.5
Average brood size (where observed)	3.1	2.4	3.5	3.5	2.8	3.0	3.3	3.0	3.2	2.8	3.1
Chicks ringed	46	20	63	70	47	90	132	119	177	133	189
Adults ringed/recaught	11/9	3/4	9/13	17/8	14/9	21/14	18/14	16/15	22/17	19/17	20/22

It did seem that pairs along the north coast fared the best though (average brood size of 3.7), followed by Lizard and Penwith (3.4), central Cornwall (3.0), whilst those in the east of the county suffered most in the dry weather (just 2.3).

We continued our run of bizarre movements as well, with a non-breeding male (with a regular female) in an established site in Penwith having been ringed as a chick in 2017 in Northumberland. This is our furthest movement to date (at 587km) and it'll be interesting to see if it stays to breed now.

We sadly also received three reports of ringed birds dead on the A30 during the year, all on the open dual carriageway between Carland Cross and Fraddon. Along with a bird that had to be put to sleep after becoming tangled in a barrbed wire fence, this was a poor year for our chicks.

Portreath Kittiwakes

With spring migrants back in earnest and everything singing and nest-buiilding, it was a good time to have another look at the Portreath Kittiwakes.

Probably only 75% of the birds were back on ledges, with plenty of space left to fill, so hopefully birds just aren't settled yet. Despite the sun, a bit of hazy sea fret made life a bit difficult ring-reading but we still managed to pick up three of our regular French-ringed birds.

OBM-WLN was ringed as a chick at Pointe du Raz in 2011
and has been seen regularly at Portreath ever since

RYM-ROO is a 2014 chick, first seen at Porthmissen (near Padstow)
in June 2018, then at Portreath in July 2018 and regularly since

The third bird avoided being photographed, but NRL-ROM was a 2015 chick and has been at Portreath since 2018. All useful information of course on how our birds roam around the Channel between breeding sites, so fingers crossed this will be the start of a productive season.

So the breeding season starts

With the run of fine weather this week, it's the perfect chance to have a first look at some of our breeding seabirds. First stop yesterday was Mullion Island, where a few photographs from the cliffs revealed that the Cormorants were well into the breeding season, with some nests even having half-grown chicks exercising their wings. A scan of the photos revealed at least 69 nests, which is on a par with last year's record 73 nests.

We then sat on the cliffs overlooking Rinsey zawn and waited patiently for sitting Shags to shuffle and show us what they're up to. In total there were 11 occupied nests, but of these just one had laid, with three eggs present. This compares to well to previous years, with first eggs noted (from 2013-19) on 8th March, 22nd April, 13th March, 1st April, 22nd March, 9th April and 25th March.

Storm Eunice delivers a lost swan

Storm Eunice brought a fair amount of destruction to the southwest, but there was one arrival that was a rather unexpected. When going out onto their farm near Lelant, one family were surprised to find an exhausted young swan in one of their fields. They picked it up and found that it was ringed, with both a metal ring and a yellow colour ring: CDBH.

CDBH recovering on a Cornish farm (Selena Richards)

With a bit of detective work, it was found to be a bird ringed as a cygnet in a park in Dublin in September 2021. It was quite happily seen in the park over the winter, last seen on 4th January, but then perhaps got caught up in the storm and ended up in a Cornish field on 24th February. The Dublin project has ringed 800 Mute Swans since 2015 but have never before had a sightings in England. The 353km this bird travelled (wind-asssited) is also a record for the project.

This is the first record of an Irish Mute Swan in Cornwall and in fact there have been very few ringing records of Irish Mute Swans making the Irish Sea crossing at all. There have previously been eight records in England (strangely mostly in and around the West Midlands), five in wales and two in Scotland.

Many thanks to Selena Richards and family for finding and reporting CDBH, Mark Whittaker for tracking it down and Graham Prole from the Irish Midland Ringing Group for the quick reply with the details.

Our ninth Herring Gull visits France

Perhaps it's the fact that the weather is so wet and windy in Cornwall at the moment that another of our juvenile gulls has made the trip across the Channel to France. On Friday, W:377 was seen on the southern coast of Brittany near Sarzeau, loafing on a raft (for terns) with other juvenile gulls.

W:377 at Marais de Suscinio

Ringed as a chick in Falmouth in 2020 it hasn't been far before, last seen at Stithians Reservoir in August last year. See below it's short history, very helpfully prduced by the app created for us by Stephen Vickers, which you can use to report gulls to us here.

This is the ninth of our colour-ringed birds to have been seen in France, so it'll be interesting to see if it returns in the spring. Many thanks to Catherine and Michel Marcaultfor reporting W:377 and also for the photos.

W:377 at Stithians Reservoir in August 2021

Sibe Chiff overload at the sewage works

The middle of January 2022 saw the first spell of cold, calm weather, perfect to start our winter ringing at our local sewage treatment works (STWs). These sites are a haven for insects in the cold weather and where there are insects there are always going to be birds. In winter, the resident wagtails, Wrens and Robins are joined by large numnbers of Chiffchaffs, including Siberian 'tristis' Chiffchaffs, possibly from as far east as the Urals. Once considered a rarity in the UK, it's now become more apparent how frequent they are, especially in the far southwest.

Over the week of cold weather we managed to ring at four of our regular sites, all of which produced plenty of birds. We've ringed at these sites for several years, so recatching birds from previous winters is always interesting and it's rare to see a bird ringed at one site moving to a different one in a subsequent winter. In fact one of the birds recaught at Constantine had been ringed there five years previously, in January 2017! We do also catch birds from elsewhere which again gives us an insight into where these winter birds come from.

The table below shows the total number of Chiffs caught at the sites over the week, including new birds and those already ringed:

	Chiffchaff	Siberian Chiffchaff
Gwennap STW	44	7
Brew STW	39	12
Ponsanooth STW	31	2
Constantine STW	21	-
TOTAL	135	21

 

It's fascinating to see how the proportion of 'tristis' birds varies across the sites, with almost a quarter of birds caught at Brew, down to none at Constantine. This may be due to the surrounding habitat to some degree, as Constantine is very much an inland wooded valley, whereas Brew sits right down near Lands End on a scrubby hill. What's also interesting at Brew STW is that it sits at the top of the Nanjizal valley, where large numbers of Chiffs are ringed on autumn migration. Some of these stay for the winter, so it's interesting to look at when these birds first arrived in the valley. The Nanjizal Chiffs recaught at Brew this week were ringed in February 2020, October 2020, November 2020, and from 2021, on 22nd September (a surprisingly early date), 10th October, 5th and 11th November. As for the 'tristis' Chiffs, they were all ringed much later in the autumn in November 2021, on 18th, 20th and 24th. Some Nanjizal-ringed birds do also move through and winter elsewhere, with birds ringed on 25th October and 11th November recaught at Ponsanooth (44km), and a bird ringed on 6th November recaught at Gwennap (43km).

 

As for birds from further afield, we saw just one of these, with a Chiff ringed on Hartlepool Headland on 19th October recaught at Gwennap, 565km as the Chiff flies.

We're back to mild, wet weather now so fingers crossed for some more cold settled weather and we can get back to the works and see what we missed this week!

Eight colour-ringed gull species from eight countries!

We recently received details from BTO of some colour-ringed gulls reported to us over the last cpouple of weeks and it's quite an amazing selection! In total we received details of eight different species from eight different countries:

• Common Gull from Norway on the Asda roof in Penryn
• Yellow-legged Gull from Switzerland on Hayle estuary
• Caspian Gull from Poland at Coverack
• Mediterranean Gull from Belgium at Swanpool, Falmouth
• Black-headed Gull from Denmark at Helston boating lake
  
• Herring Gull from Wales at Coverack
• Lesser Black-backed Gull from Portugal on Hayle estuary
  
• Great Black-backed Gull from Loee Island in Newlyn harbour

This again goes to show a) how important Cornwall is to wintering birds from right across Europe and b) how important colour-ringing is in showing this.

It also shows that these birds can turn up pretty much anywhere, all seen by local birders with a decent 'scope or camera. So if you're out birding over the winter do keep an eye out for anything out there sporting a shiny colour ring and get reporting.