Start of the winter Chiffs

It's not often we start our winter sewage works ringing in December, but a couple of weekends of cold weather recently gave us the chance to venture out to a couple of sites.

Gwennap is often our most productive site and a few hours last weekend saw us catch 101 birds, including 59 Chiffchaffs. Of these, just four were birds ringed in previous winters, predictably all at the site. The highlight though was a smart Grey Wagtail which was already carrying a ring, but not one of ours. It had actually been ringed as one of three chicks in a nest in Budock Water in April, 9km from Gwennap.

The Grey Wagtails in the nest (Sam Pitt Miller)

This last weekend we were then able to get into Brew sewage works, near Sennen, right down in the far west. It needs a calm day to net this exposed site, so we have to make the most of the chance. A short morning produced 61 birds, of which 45 were Chiffchaffs. Being so close to the autumn ringing site at Nanjizal, several of these were already ringed, which gives a nice insight into the arrival timing of wintering birds (more on that later). Most were from this same autumn, but four were ringed at Nanjizal in autumn 2022, so were returning birds.

Brew is also our best site for Siberian Chiffchaffs (tristis race) of which we caught two, both of which were quite subtle birds (as below), not the cold grey birds we sometimes see.

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.

New Year, new Chiffs

It's been a long time since we've blogged, but what better time to change that than New Year. Today was a rare calm day and despite not being very cold we decided to have a couple of hours at Gwennap Sewage Works anyway. The vagaries of ringing at sewage works is that we often only use the smallest size rings (AA) and today was no exception. In the two hours (and just three nets) we ringed 28 Chiffchaffs, including this very smart tristis Siberian Chiffchaff. Unfortunately we didn't recatch any ringed birds from last winter (when we ringed 44 Chiffchaff here), but once the colder weather arrives I'm sure we'll be catching more.

There were well over 40 Chiffchaff on site (and two Yellow-browed Warblers), so plenty more to keep us occupied on the next calm day. The bycatch wasn't too bad either: Firecrest, two Long-tailed Tits and the obligatory Wren.
 

Zilpzalp at Gwennap

In the UK most Chiffchaffs will be summer visitors, spending the winter to the south and west of us, neatly shown by the online ring recoveries map, showing most recoveries in France and Iberia:

But the wintering birds we see here in Cornwall come from points north and east, a fact confirmed today with the capture of a bird at Gwennap Sewage Works that was wearing a ring from the Hiddensee scheme in Germany!

There have been just 12 reports of German-ringed Chiichaffs in the UK so this was a pretty special bird! This was pretty lucky as we only caught three Chiffchaffs, compared to 23 at the previous attempt when it was colder.

First Chiffchaffs of the winter

Mist-netting has been a bit slow of late, but with the weather finally turning cold and the wind amazingly light we took the opportunity to make our first visit to the local sewage works. First stop was Gwennap, where as many as 65 Chiffchaffs were feeding in low hedges and bushes around the site, so with just two nets we were able to catch 35 birds, including a single 'tristis' bird and also two birds ringed last winter (both on 5th January). We only caught five adults, so two ringed was a reasonable ratio!

Next stop was Carnon Downs, where there were fewer Chiffchaffs (perhaps just 25), but they were all now in the tops of the trees in the warmer afternoon, so we only caught a single bird. But we did see another 'tristis' bird and also a ringed bird, so we'll be back again as soon as the wind and weather are favourable.

Apologies for the lack of photos, but we were a bit busy ringing birds to take photos...

Parisienne chic at the sewage works

It only seems right that our first ringing session of 2017 should be rather similar to our last ringing session of 2016, so it was off to the sewage works this morning. In two nets we managed to catch a non-too-shabby 67 birds, which included no fewer than 31 Chiffchaffs.

The only slightly shabby thing about the morning was the state of the forehead of the bird below, as it seemed to be moulting in new head feathers. But it may just be Parisienne chic, as it was already wearing a French ring, so it'll be fascinating to see where it's from!

 

There are just 26 records of French-ringed Chiffchaffs being found in the UK, with two of these being in Cornwall, including one we recaught at Carnon Downs sewage works back in February 2012.

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.

Commuting Storm Petrels and warblers

We recently received some interesting recoveries from the BTO, mostly of some pretty fascinating Storm Petrel movements. In the past we've traded quite a few birds with Ile Banneg, home to France's largest breeding population of Storm Petrels, but these reports were notable.

Over summer 2013 at Hot Point, Lizard, we only caught one French-ringed Storm Petrel (compared to four in 2012), but we've just heard that we had a great run of records of birds going the other way. In total five birds ringed at Hot Point in 2013 were recaught on Banneg later in the year, with a further bird ringed in 2012 unfortunately found predated there. This compares with just one going that way in 2012.

But what was interesting was when these birds were caught, with some making very quick movements over the 178km to Banneg. Birds ringed in June were recaught 35 days, 32 days and four days later, whilst a bird ringed in July was recaught three days later and one ringed in August was recaught the next day! I'm sure birds regularly commute backwards and forwards across the English Channel, but in theory non-breeding birds are more attracted to tape lures, but I bet these movements are of breeding birds...

We also just received details of a few movements from last autumn, including a Sedge Warbler ringed at Marazion and recaught in France five days later (but it did weigh 11g when ringed so was obviously getting ready for the off), a Spanish-ringed Reed Warbler recaught at Gunwalloe was ringed on spring migration (the first to be found in Cornwall), and a Chiffchaff we caught in November had been ringed in North Yorkshire a month earlier. This bird had come over 500km and was presumably on migration through the country when ringed.

The map below shows where these birds were ringed/recaught: Storm Petrels (red), Sedge Warbler (green), Reed Warbler (blue) and Chiffchaff (yellow). 

Chiffchaffs getting ready for the off

Finally the weather improved for long enough on Wednesday to get out and put up some nets! With winter fast coming to an end we took the opportunity to make a late visit to one of our sewage works sites at Ponsanooth. We ended up with 21 new birds and 13 retraps, including the typical sewage works fare of two Grey Wagtails, a Siberian Chiffchaff and several 'normal' Chiffchaffs. Highlight though was a net round of three Firecrest (including the two males below) and a Treecreeper, the latter being the first one ever caught by the group!

What was more interesting though was the weight changes in some of the retrap Chiffchaffs. EKT783 weighed 7.9g when ringed on 17th December, up to 9.9g now. EKT753 weighed 7.8g when ringed on 26th November, then 7.6g on 12th December and 7.9g on 29th January, now weighing 8.4g. Finally one of our controls (a bird ringed elsewhere), DYP947, weighed 8.3g when caught on 29th January now weighs 9.7g.

These birds were also fat, scoring 3 or 4 (on a scale of 0-8), compared to earlier in the winter when the carry little or no fat (score 0 or 1). These are both sure signs that spring is on its way and birds are preparing to move back north...

Interesting Sibe Chiff at Carnon Downs

The forecast cold weather didn't really materialise, but we were out anyway and with a few birds in the treetops at Carnon Downs sewage works (at least 15 Chiffchaff and two Siberian Chiffchaff) we decided to chance our arm. First bird caught was an unexpected adult Magpie; a new bird for Terry.

Second net round was even better, with the same net producing another adult Magpie and a Grey Wagtail; ANOTHER new bird for a now very chuffed Terry. Amazing what a random 40' net can produce! Interestingly, this second Magpie had a very old retained secondary, looking to be from a good couple of years ago.

Happy faces extracting Magpie and Grey Wagtail

Retained secondary, but from how many years ago?

It was a bit quiet first thing, but as the flies got moving things picked up. We ended up with 40 birds, including 10 Chiffchaffs, two Firecrest (always nice), Grey and Pied Wagtail and a very smart Siberian Chiffchaff. Although the photo doesn't really show it, this was one of the rather grey Bonelli's Warbler lookalikes, which are actually rather uncommon down here. Characteristically for these birds it showed the very long, broad supercilium.

 

Compare this bird with these other two Sibe Chiffs caught in the last couple of weeks. The bird on the left (at Gwithian) shows more green and yellow tones with an obvious, but not overly long, supercilium with a yellow hue in front of the eye, whilst the cold bird on the right (at Ponsanooth) shows no green tones and has a very much reduced supercilium in both width and length.

First Siberian Chiff of the winter?

With a hint of cold weather it was time to start poking round sewage works again and this morning we tried a new site for us, Gwithian, where it's nice and easy to net. Six nets in an open rectangle nicely cover the small site and although we only caught 18 birds, 10 of these were Chiffchaffs.

Of the 10 Chiffs, most were rather normal-looking, but one bird did look rather eastern... It's possible this is just a rather bright tristis Siberian Chiffchaff and it certainly called like one when released. But it does have quite a lot of green tones on the mantle and flight feathers, so not the most straightforward.

In comparison, all of the other birds looked more like the one below which was interestingly already ringed. We won't get the details on this bird for a while, but the ring was issued to East Dales Ringing Group in North Yorkshire, so a nice green collybita it is. Supposedly a photograph never lies, but check the difference in plumage tones in these two pics of the same bird: top a fancy DSLR and bottom my iPhone. Not surprisingly the DSLR looks to be a truer reflection of what the bird should look like!