3 May 2021

More Mullion Cormorants

We've never had the chance to make two Cormorat ringing trips over to Mullion Island, but the spacing of the colony this summer allowed us to get over safely again at the weekend. Thanks again to Lizard Adventure we took a few kayaks over and landed both side of the island so that we could corral the young birds in the Sea Mallow.

Some of the larger birds we let waddle off onto the top of the island so we could concentrate on the medium-sized chicks. With an efficient team, we were able to ring 25 chicks, 23 of which we also gave a coded orange ring which can be read at distance. We strictly limit our time on the island (to no more than an hour), so had to leave another dozen chicks unringed. But with a record number of nests this year (at least 73) this was always going to be a productive year. We sadly also didn't have time to count the Great Black-backed Gull nests on the island either, but with plenty of birds sat on eggs (and even a left-over Manx Shearwater meal) we hope they too will have a good year.

Across the two visits we colour-ringed 44 chicks this year which is by far the most we've ever ringed, so it'll be fascinating to see how these birds get on and where they end up. Thanks again to Lizard Adventure for the loan of their kayaks (and guide) and wehope to be working with them again soon when it's time to ring gull chicks.

17 April 2021

Trewavas Kittiwake in Wales

We were recently contacted by Josie Hewitt, who's spending the summer monitoring seabirds on Skomer Island in south Wales. As part of their regular monitoring, Josie photographed a colour-ringed Kittiwake in the week which wasn't local, so got in touch as she thought it might be one of our Cornish birds.

It turns out that Black N5 was indeed one of our Trewavas Head birds, ringed as an adult in June 2018 and interestingly not seen since. In our experience, adults present in the colony early in the season are often wanderers, but the fact this bird was ringed in June (as a breeding bird) is a bit confusing! But considering the main Trewavas colony has failed in the last two years, maybe this adult has moved on, so it'll be interesting to see if it remains over the summer.

This also isn't as unprecedented as it might seem, as our other monitored colony at Portreath has a regular breeding bird that was ringed as a breeding season adult in the breeding season north Wales!

8 April 2021

First Mullion Island trip of 2021

With the easing of restrictions coming at the perfect time, we took the chance of some flat clam seas this morning to make our first trip over to Mullion Island as part of our annual seabird monitoring. Earlier in the season we'd photographed the island from the clifftop and estimated 63 occupied nests, which is the most we've seen on the island since we started monitoring nests in 2013.

With enough big chicks to make a ringing trip worthwhile, with the help of Lizard Adventure we kayaked over and realised that we'd underestimated the number of nests, with the colony spreading deep into the Mallow, hence not visible from the mainland. We need to review the revised estimate, but at over 70 nests this is quite significant.

With three small ringing teams, we managed to ring 21 chicks, with 20 also large enough to take an orange colour ring to allow us to better track movements.

Many thanks to the ringing team and we were on and off the island in under 45 minutes, so minimising disturbance as much as possible. It'll be fascinating to see how this cohort of chicks fare and there may be more to ring yet as many nests still had unhatched eggs!

28 January 2021

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!

2 January 2021

New Year, old Chiffs

It seems to be New Year tradition now that the Cornish weather turns cold enough and calm enough to warrant a visit to the local sewage works. Today was no exception and thankfully the hail showers stayed away long enough to allow a couple of hours mist-netting at Gwennap Sewage Works. There were a LOT of Chiffchaffs around, picking insects off the tanks and from the bushes and small trees surrounding them. My estimate of 80 birds was probably rather conservative.

It only took two nets around a settling tank to keep me pretty busy, catching 81 birds! Of these, an impressive 56 were Chiffchaffs, including seven ringed in previous winters. Four had been ringed on 1st January 2020, with others ringed on 19th January 2020, 4th January 2019 and 5th January 2017. The latter bird (HHB667) was caught again in December 2017 but not since, so in its fourth winter at the site is remarkably site faithful. The national longevity record for Chiffchaff is only 7 years 7 months, so HHB667 is quite exceptional for a wintering bird.

In amongst the 'nornal' Chiffchaffs were several paler, eastern Siberian Chiffchaffs (tristis race) and I was lucky enough to catch four, including an exceptionally pale frosty bird. These eastern visitors normally make up 10% of our wintering birds, so the four caught is about the norm.

Some of the 'bycatch' was interesting as well, including Firecrest, three Grey Wagtails, Pied Wagtail, three Bullfinch and Meadow Pipit. With the weather set to stay cold and calm next week, we'll hopefully have more to report soon.

21 November 2020

Cornwall is a colourful place (for rings)

Over the years various members of the group and local birders have reported a wide variety of colour-ringed birds in the county. As we run a long-term urban gull project, not surprisingly our most-reported species is Herring Gull, but what about other species? A quick look at the numbers from the BTO's DemOn (Demography Online) database gives us records of over 4,500 colour ring reads of 26 different species, summarised by year here:

As expected, other gull species feature right at the top, followed by species that we run RAS (Retrapping Adults for Survival) projects on: Kittiwake, Jackdaw and House Sparrow. We don't ring any smaller gulls ourselves, so all of the records of Mediterranean and Black-headed Gull resightings come from other schemes, often abroad. In fact a lot of the larger gulls are from abroad as well, with French Great Black-backed Gulls topping the table, closely followed by Belgian and French Mediterranean Gulls.

Polish-ringed Black-headed Gull at Swanpool, Falmouth (Mark Grantham)

French-ringed Great Black-backed Gull at Southerly Point, Lizard (Terry Thirlaway)

Belgian-ringed Mediterranean Gull at Coverack (Mark Grantham)

Irish-ringed Lesser Black-backed Gull on Copperhouse Creek, Hayle estuary (Mark Grantham)

Lower down the list are some more unusual species, details of which we've blogged about before, including:

Some of the other more unusual resightings include these smart birds:

Green A61 was seen at Lizard Lighthouse in March 2018 before being seen back on
Skokholm Island where it was ringed just nine days later (Terry Thirlaway)

This Dutch-ringed Sanderling was a regular on Marazion beach in winter 2016-17
and also once in January 2018, but was also regularly seen on
autumn passage in The Netherlands (Ben Porter)

This Dutch-ringed Sandwich Tern at Sennen Cove had been seen
three weeks previously in Tyne and Wear (Clive Richards)

We're always keen to receive new sightings though and can help in tracing birds with the different coordinators, so if you're lucky enough to see any colour-ringed birds then drop us an email with details - westcornwallringinggroup@gmail.com

3 October 2020

Ageing gulls

I don't mean ageing as in the dark art of knowing if that dappled Herring Gull is a third or fourth calendar year bird, but more some of the interesting changes in plumage and bare parts we see as our colour-ringed Herring Gulls grow up.

W:245 was ringed as a chick on the University of Exeter campus in July 2018 and has been seen just seven times at various sites local to Falmouth since. It's interesting to look at how its bill colour has changed this year though, seen in the montage below.

It's also interesting to see how moult progresses through the year as birds rapidly change appearance. W:178 was also a chick ringed in 2018, this time in the middle of Falmouth town, and has been seen eight times since. Both photos below show W:178 at Stithians Lake, in June and September, but note how quickly it has grown through new flight feathers (with 'mirrors' on the tips) and also adult-type wing coverts.

W:178 on 29th June

W:178 on 25th September

Some birds really do change appearance in a matter of months as well. W:249 was also a 2018 campus chick and has been seen eight times in the local area. Below are a few photos of W:249 just from this year and the change is striking, although photos can be deceiving as the bird looks to have taken a step backwards in its moult in September!




21 September 2020

Colour-ringed Ospreys galore

It's been a good autumn so far for Ospreys in Cornwall, with sightings being reported from numerous sites across the county. Interestingly, several of these birds have been photographed with colour rings and they tell some interesting stories.

Earlier in the monnth, one of two birds at Devoran was seen to be ringed and with a bit of persistence was read by photographer Andy Wilson as KC7, aka 'Tywi'. This male was ringed as a chick in Wales earlier this year at the Dyfi Osprey Project and was last seen there on 25th August.

Blue KC7 at Devoran (Andy Wilson)
Remarkably, a few days later another Osprey was photographed at Devoran but with a different ring! Blue JF1 was ringed as a chick in Scotland in 2017 and even more remarkably had been seen at Devoran that autumn, as detailed on the blog here. With KC7 also still present, it's amazing tho think that two known individuals from different countries were feeding together on the same stretch of river.

Blue JF1 at Devoran in 2020 (John St Ledger)
One other bird we've yet to receive details of is Blue 260, which was on the Gannel estuary, Newquay at the start of September. We presume it's a Scottish bird but will wait and see.

Blue 092 (or 260) on the Gannel estuary (Rhys Ellis-Davies)
This again just goes to show how useful colour-ringing is in tracking birds and the increase in value it gives to bird recording.

15 August 2020

Interesting moulting gulls

Since the end of last year we've been collating photographs of as many of our colour-ringed birds as possible, hoping to document plumage changes of known individuals. This has come up trumps recently with some quite interesting moult recorded. Here are two of the more interesting birds which might be interesting to gull enthusiasts.

W:249 was ringed as a chick in July 2018. The photos below show the bird as a second-winter bird then moulting into second-summer plumage.

January 2020

February 2020
August 2020  

W:369 was ringed as a juvenile in August 2019. It became very worn into its first-summer, but looks to have fitted in quite an extensive moult in a few weeks in its first autumn.

February 2020

June 2020
1st July 2020

14th August 2020

We're not sure how much work has been done on moult progression in large gulls, but it'll be interesting to follow this in the future.

30 July 2020

2020 Barn Owl update

With the first Barn Owl broods now all ringed and boxes monitored, it's a good time to take stock and see how the season has gone. Averaging out the numbers in the table below, we can see that the project continues to grow and for the first time we have data from over 100 boxes which is a greeat achievement. The occupancy rate contineus to be relatively low, but we hope that previously unoccupied boxes will be taken up by new pairs as the years go by. Of the boxes monitored, clutch sizes appeared to be slightly down on previous years, but the subsequent brood sizes didn't necessarily reflect this. The figure of 3.2 hides a much more complicated story though.

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Sites visited 32 34 32 44 41 47 64 85 87 106
Unoccupied 2 7 12 11 11 12 23 34 36 43
Occupied but no breeding 13 2 7 7 7 8 5 4 3 4
Average clutch size
(where observed)
4.8 4.1 3.6 4.6 4.6 4.6 5.3 5.2 4.7 4.6
Average brood size
(where observed)
3.1 3.1 2.4 3.5 3.5 2.8 3.0 3.3 3.0 3.2
Number of chicks ringed 33 46 19 63 70 47 90 126 119 170

It was apparent as the season progressed that brood sizes (and numbers of chicks ringed) was decreasing, but this is always hard to measure. But if we simply look at the number of chicks present at ringing through the season then a trend does seem to appear. The sample sizes are rather low, but we do think there's something in the data.

The much lower brood sizes later in the season we presume was due to the period of very unsettled weather, with plenty of rain. This makes feeding very difficult for adults which obviosuly has knock-on effects for chicks. We hope to be able to place cameras in numerous boxes over the winter (watch this space on that), which will give us much better data over the coming years.

18 July 2020

Kittiwakes fail AGAIN

With slightly higher hopes than last time, we paddled out to the Kittiwakes sites at Trewavas Head to check up on the c140 pairs nesting at the three sites. The first stop was Trequean Cove where there were encouragingly still good numbers of birds, but a closer look revealed just 11 nests still with chicks which was a poor return from the 40 sitting birds we found in May. There were plenty of our colour-ringed birds and so far this season we've seen 13 birds at Trequean that have previously been seen at the main colony or at the engine houses colony. This might suggest that birds are slowly moving along the coast, but why they might be doing this is unclear.

The reason for this became apparent as we paddled along to the engine shouses, where the 28 pairs we'd seen in May were down to just half a dozen forlorn birds sat on empty ledges. The main colony at Trewavas Head wasn't much better either, as despite there being plenty of birds still present (including 17 of our own colour-ringed birds and a French bird), there were just three nests with chicks, down from the 65 sitting birds in May. Why these birds have failed again so disastrously is a a mystery, but it's interesting that the nests dominated by younger pairs seem to be doing better than the established sites, so maybe change really is for the better.

To back up this move away from the main colony, we received an email from fellow Kittiwake workers in France (Professor Emmanuelle Cam from the University of West Brittany) with a report of two of our birds seen in their colonies in Brittany in recent weeks. Both of these birds are regulars at Trewavas Head:

  • EC was actually a chick ringed (metal ring only) on the Isles of Scilly in 1996, but we recaught it in 2015 and added a colour ring. It's been seen every year since as a breeding bird, last seen here on 2nd June 2020.
  • EN was ringed as an adult at Trewavas Head in May 2015 and was seen 2015-2018 but not seen in 2019. It was however seen back in the colony on 19th May 2020.

These are the first of our birds seen in your colonies, and it's great to have the coverage that produces these sightings. It'll be interesting to see what happens in the coming years and whether the colonies can recover.

26 June 2020

Mullion gull numbers

With the last of the (supposedly) calm seas for a while, we took the chance to get over to Mullion Island to ring any surviving Great Black-backed Gull chicks. At the start of the month we counted at least 59 nests with 146 eggs/chicks, but we know that survival is incredibly low to fledging, so we never know what to expect.

Worryingly the first chick we found on the island was tiny, perhaps only a week old and far too small to ring. With most chicks on Looe Island a good size now (we visited two days ago to ring them there) we wondered if Mullion birds were nesting far later and we'd struggle to find any chicks big enough to ring. The remainder of the island was a mixed bag though, with some nests still with eggs, one just in the process of hatching.

However, we did also find enough larger chicks to keep us occupied and in the end we colour-ringed 14 birds. This is still only 10% of the eggs/chicks we counted three weeks ago. but seems typical of recent years. We'll make a return trip in a couple of weeks time to see if the remaining chicks have survived, so the number may yet improve.

2013 2014 2015 2016 2017 2018 2019 2020
GBB Gull nests - 62 37 83 70 60 71 (59)
GBB Gull eggs/chicks 98 174 90 204 166 - 195 (146)
GBB Gull chicks ringed 4 17 12 13 5 3 16 14

For the first time we also saw not one but two of our own ringed birds on the island, of an age now where they're probably breeding. It was good to see the rings on these birds were still looking good, as in some cases they can wear quite rapidly, making them hard to read. See below examples from Looe Island (taken two days ago) of worn rings from 2010 and 2011.

LDA2 was ringed as a chick in 2015 and has been seen several times at Southerly Point, Lizard
and once at Coverack. It was last reported in November 2018.

With a remarkably similar history, LBH7 was ringed as a chick in 2014 and is also a frequent visitor to
Southerly Point, has also visited Coverack once and was last reported in September 2018.

Not all ring wear is even though, as the photos above and below are actually different sides of the same ring (L:AL8)

Strangely there were still also one or two Cormorant chicks in the nest which is very late, but most were long gone, leaving just their mallow-stick nests as evidence.

A sorry reminder of the times we're now living in