Sunday, May 25, 2014

Congratulations...

...to my little sister Kate who got married yesterday. Wishing her and her husband Anthony all the best!


Saturday, May 03, 2014

Falsterbo (Lesser Whitethroats)

I've done a few things over the last few weeks but they all fit into one of two categories: not interesting enough to blog about or vaguely interesting but lacking enough time to follow them up with a thought-out post. Other than the couple of birds I handled at Portland back in March, I haven't done any ringing since I was in Sweden last year. I took advantage of the bank holiday weekend and reasonably cheap flights from Heathrow and decided to head back out to Falsterbo for a couple of days rest and relaxation (if you can call a 03:30 start resting!).

Species of the day at the lighthouse was Lesser Whitethroat, with 11 ringed (along with 11 Willow Warblers, a Blackcap, a Dunnock, a Chaffinch, a Linnet, and three Greenfinches). Ten of the Lesser Whitethroats proved to be second-years plus one adult (3+cy).


The first bird we caught, a second-year, looked at first glance to have undergone an extremely extensive pre-breeding moult with four of the secondaries on the right wing new and the entire tail fresh.


On closer inspections, it seems like the bird had lost and regrown the tail and some of the secondaries on the right wing. Just one secondary had been moulted on the left wing, and the rest of the moult in e.g. the coverts was quite normal.


The second bird was easier to age as a second-year; it had retained three juvenile greater coverts:


This bird had retained most of the tail. Actually in a damn good condition for a second-year Lesser Whitethroat!

It was nice to catch an adult (3+cy) to compare with the second-years. The wing if overall much fresher and darker, while the primary coverts have a subtle grey fringe (vs brown on second-year birds).


This second-year nicely demonstrates the rather narrow juvenile flight feathers, compared to the adults broader primaries and squarer secondaries:


The first bird in the blog post shows a fault bar across the tail, indicating simultaneous growth of the feather tract. As I've said before(!), it's often taken that this means the tail must be juvenile (since juveniles grow the entire feather tract simultaneously when they're in the nest). In the case of the first bird in this post, that's not the case since the tail has been entirely lost and regrown — it's equally as likely that that could happen to an adult as to a young bird, so it gives no worth for ageing. This second-year, however, does show a fault bar in the tail that is a result of the juvenile feathers being grown simultaneously:


More useful, and something that can be used as an ageing criteria, is the 'same' continuous fault bar across the wings. We can safely assume that this must have happened in the nest; an adult bird losing all of it's flight feathers at the same time surly can't stand much chance of survival! Beyond the fault bars, this bird shows the typical suite of plumage features associated with a second-year.


Finally, this second-year bird had its face encrusted with pollen; not from a local food source!

Sunday, March 16, 2014

Quiet(er)

If yesterday was relaxed, today was flat out on its back. Ringing totals again reached the dizzying heights of two, though today's species variety was half that of yesterday with both of this morning's birds being Common Chiffchaff.


Sightings of note included a Sand Martin whizzing north overhead and... well... pretty much as yesterday, less the Red Kite and any Wheatears. I took some time to have a look at some of the Bill's common residents include, of course, Dunnocks (of which there are plenty). I was particularly pleased with this individual: it's a 2cy male that was singing in the lighthouse garden.


I got really excited when I set the 'scope on it. You can see why, right?


Last night finished with a post-blog post Little Owl calling outside; this evening is finishing with a Red-legged Partridge calling from the obs crop field and a roast dinner.

Back to London tomorrow. Acton can offer phone signal and reliable internet, but it can't offer views like this...

Saturday, March 15, 2014

Portlandia

I've run away from London for the weekend and I'm spending a bit of time at Portland Bird Observatory in Dorset.


We started the morning with a few hours of ringing. We ringed just two birds, though they were interesting and unexpected, respectively. First bird in the net was a 2cy Song Thrush that had undergone a really extensive post-juvenile moult last year.


It had moulted all median coverts, the inner nine greater coverts, the carpal covert and A1 on both wings, plus T1 on the left and T1–2 on the right. Although I'm used to seeing birds in Scandinavia with quite limited post-juvenile moult (usually just a few greater coverts and often not even all of the median coverts moulted), this bird's moult was extensive even by British standards; it's by far the most extensive post-juvenile Song thrush moult I've seen.


Usually, I assume any replaced tail feathers in thrushes to regrowth following accidental loss. However, the new R1 on the left hand side on this bird I suspect might be part of the post-juvenile moult. It certainly fits the pattern for “normal” moult, and with the rest of the moult being so extensive it wouldn't be too surprising if it had also moulted a tail feather.


Jenni & Winkler in Moult and Ageing of European Passerines give a range of greater covert moult 0–9, with mean 3.9 and mode 3 for 1,103 Song Thrushes studied; they note that two tertials were moulted in 0.2% of 764 birds, and that no birds of 755 were found to have renewed any tail feathers. However, they do then reference several sources stating that “In England, 1[c]y with all GC and some R moulted were found exceptionally”.

The second bird was not so interesting — they undergo a complete post-juvenile moult, so what is there to look at?! — but was quite unexpected: a Skylark. Not something that's caught often down here, and even less so in the lighthouse garden. The iris was a rich brown; the two non-adult birds (and indeed the two juveniles) I've handled previously had grey-green irides. That might be age related, but without further study with known age birds there's not really a lot else we can say.


Birding was quiet but still pleasant, with a 2cy Red Kite, two Peregrines, and several Ravens passing over the obs. Joe and I took a wander late in the morning, with highlights being a couple of smart Wheatears and, nice for me after so long not having seeing any, species like Rock Pipit, Stonechat, and Fulmar.


The harbour held three dark-bellied Brent Geese and some Red-breasted Mergansers.

Sunday, March 09, 2014

Barnes

Did you think I'd forgotten you? Perhaps you hoped I had. Don't waste a breath mourning Miss Barnes. — Frank Underwood, House of Cards
So, yes, I've been gone for a while: I've been otherwise engaged with things that you really don't want to have to hear about; and yes, I'm slightly addicted to House of Cards. Or was, I should say — I finished season two a week after it was was released. I'm looking to get a wrist band, W.W.F.U.D? He's my new role model in life.

Spring arrived in London today and the world and his dog were out to enjoy the sunshine. Against my better judgement, I jumped on a bus to WWT Barnes. The place was crawling with small children. Thankfully, their little legs can't carry them as far as the wader scrape hide, and I found relative solace in there. I notched up forty species over a couple of hours on side — not bad for London, though there wasn't particularly anything of great note.


I spent most of my time taking a look at some of the dabbling ducks that were on the scrape, particularly the Shoveler. Having caught a bird last autumn and learnt a little bit about ageing the species, I was keen to see how things were now, some four months later. One question I always wonder about is when — or if — young birds moult the tail and/or tertials. It was nice to see that the 2cy birds today had retained all of their juvenile tertials. The difference between the retained juvenile tertials and the adult birds' tertials was noticeable, even at range. No birds came close enough to check the tail, although it was apparent even at distance that the belly feathers — even on some of the 2cy birds that were more advanced in other aspects of body plumage — were either retained or “immature”, being brown and scaly compared to the red-chestnut flanks.


Adult (below) and 2cy Shoveler — this 2cy was one of the more scaly immature-looking birds; on others, the body feathers were more adult-like but the tertials were nonetheless still retained.

I also had a play about with the slo-mo video function on my iPhone. I was pretty pleased with the results!

Monday, December 23, 2013

Resurfacing for Christmas

It's been a while, I know. I've either been lacking the enthusiasm or the subject matter — or both — for a good blog post over the past couple of month. In brief, I headed back from Falsterbo on 11th November, went shopping in Liverpool on my first day back and immediately caught flu, spend a few days in bed, then headed to London, which is where I am until — wind willing — tomorrow morning.

I raised a pair of binoculars yesterday for the first time in four weeks when we had an office outing to Eyebrook Reservoir, Leics. I was scope-less, so birding was a bit restricted — mind you, I only saw one other scope while I was there but plenty of oversized telephoto lenses; is that what 'birding' is these days? — but we had good views of the drake Velvet Scoter and a drake Tufted Duck x (?)Pochard added some study-interest to things.


As is not compulsory for this time of year, I used some of the footage to knock together the annual NatureGuides Christmas card video... complete with fake snow and dodgy music. Merry Christmas.

Wednesday, October 30, 2013

St Jude

It was too good an opportunity to miss on Monday night: 50 mph winds and cloudy skies. Perfect for lamping. We shied away from heading to our regular lamping spot, Skanörs Revlar, on the basis that the water levels might be too high, the waves were likely crashing right over the spit, and that the wind might actually have been a little bit too strong. Instead we headed to Knösen where we had a reasonable evening. As last time, low quantity but high quality.

The first bird I lamped was this male Shoveler:


I wasn't sure of the age of the bird at first. As I picked the bird up, the bright iris and the seemingly rather uniform blue lesser/median coverts made me think he bird was going to be an adult male coming out of eclipse; but other features didn't fit with that. The tail, for example, shows 'notches' out of the feather tips, a first-year feature.


It's hard finding photos of Shoveler to compare with but both Baker and Pyle give some criteria that should allow us to age this bird as a first-year based on the wing.


The greater coverts seem to be key. They fit very well with Pyle's illustration for first-year (HY) male and show the dark spot at the distal tip of the inner web as mentioned in Baker.


I was a little bit confused by the secondaries: S3 should show a green gloss in adults but not in young birds. To me, this bird shows a green gloss on S3 — but it's certainly not as green or as glossy as S4. Perhaps that's what's meant.


The tertials are short and blunt; certainly not adult breeding-type. What would the tertials on an esclipe male look like, though? Baker says “Eclipse male tertials... shorter than adult [breeding] male but still retain white flare along distal half”. Presumably the white flare relates to “white flare along distal third of shaft, mainly on inner vane” as stated earlier in the paragraph. Well, I guess this bird doesn't show (much of) a white flare...  at least not compared to this bird.



Other features, such as bill colour and overall colour of the plumage, also support the ageing as a first-year.


This was the first Shoveler to be ringed at Falsterbo since 1973.

Next up was something far less glamorous: a Canada Goose.


This was the first Canada Goose to be ringed at Falsterbo.

On my third pass across the mudflats, I caught sight of a duck that seemed to have its leg tangled in something. I went over to investigate and found an Aythya pottering about in some shallow (5–10 cm) water. The bird wasn't stuck; it was trying to get away from me... by attempting to dive under the water, hence the wildly flapping legs! I'd presumed the bird was going to be a Tufted Duck but, on getting closer, I realised it was in fact a first-year male Scaup.





The one and only Scaup to be ringed at Falsterbo prior to this one ended up being shot in Russia — lucky or unlucky, depending on how you look at it.

We finished the evening with an adult Black-headed Gull.


Not terribly exciting but, like the rest of the species ringed this evening, new for the year. The annual species total now stands at 127.

Friday, October 25, 2013

Take that, 1965!

Ringing records at Falsterbo Bird Observatory go back to 1947. The highest annual species total between then and now was set in 1965 with 121* and stood for 48 years... until today!

*Actually, there are rumours that some of the ringing back then may have been done "off peninsula" so they were cheating a bit. The highest unequivocally "Falsterbo only" species record stood at 119.

We are still missing a couple of expected species from the ringing list this year — Jay, for example — but decided we didn't want to risk sitting around waiting for one of these to drop into a mist-net. Proactive ringing was going to be the key to guaranteeing a new species record. With that in mind, we headed out onto Skanörs Revlar last night armed with a lamp and a hand-net. It was, from our point of view, a successful evening. We caught just two birds, but they were high quality: a Jack Snipe and a Barnacle Goose. The latter was species 121 for the year (and only the third to be ringed at the observatory).



It didn't take long before we caught the magic 122nd species: a Great Grey Shrike in the standardised ringing at the lighthouse this morning.


And just to make sure the record was well and truly broken, Peter and Albin set up a clap net at Flommen and caught some Twite. They were still catching when I joined them in the afternoon.


Here's a list of the species ringed at Falsterbo so far this year. Species in parenthesis have been handled as controls/retraps only and, for whatever reason, don't count on the 'official' list. Copy-pasted from FBO website, with apologies for caps lock.

MUTE SWAN
BARNACLE GOOSE
EURASIAN TEAL
MALLARD
EURASIAN SPARROWHAWK
COMMON KESTREL
WATER RAIL
SPOTTED CRAKE
COMMON MOORHEN
COMMON COOT
EURASIAN OYSTERCATCHER
RINGED PLOVER
RED KNOT
SANDERLING
CURLEW SANDPIPER
DUNLIN
RUFF
JACK SNIPE
COMMON SNIPE
EURASIAN CURLEW
COMMON REDSHANK
COMMON GREENSHANK
GREEN SANDPIPER
COMMON SANDPIPER
RUDDY TURNSTONE
SANDWICH TERN
COMMON TERN
ARCTIC TERN
LITTLE TERN
BLACK TERN
STOCK DOVE
WOODPIGEON
COMMON CUCKOO
TAWNY OWL
LONG-EARED OWL
TENGMALM'S OWL
COMMON SWIFT
EURASIAN WRYNECK
GREAT SPOTTED WOODPECKER
LESSER SPOTTED WOODPECKER
SKYLARK
SAND MARTIN
BARN SWALLOW
HOUSE MARTIN
TREE PIPIT
MEADOW PIPIT
RED-THROATED PIPIT
ROCK PIPIT
YELLOW WAGTAIL
GREY WAGTAIL
WHITE WAGTAIL
BOHEMIAN WAXWING
WINTER WREN
DUNNOCK
EUROPEAN ROBIN
THRUSH NIGHTINGALE
BLUETHROAT
RED-FLANKED BLUETAIL
BLACK REDSTART
COMMON REDSTART
(European Stonechat)
WHINCHAT
NORTHERN WHEATEAR
RING OUZEL
COMMON BLACKBIRD
FIELDFARE
SONG THRUSH
REDWING
MISTLE THRUSH
GRASSHOPPER WARBLER
SAVI'S WARBLER
SEDGE WARBLER
MARSH WARBLER
EURASIAN REED WARBLER
GREAT REED WARBLER
ICTERINE WARBLER
EASTERN SUBALPINE WARBLER
BARRED WARBLER
LESSER WHITETHROAT
COMMON WHITETHROAT
GARDEN WARBLER
BLACKCAP
GREENISH WARBLER
PALLAS'S LEAF-WARBLER
YELLOW-OWED WARBLER
WOOD WARBLER
COMMON CHIFFCHAFF
WILLOW WARBLER
GOLDCREST
FIRECREST
SPOTTED FLYCATCHER
RED-BREASTED FLYCATCHER
PIED FLYCATCHER
(Collared Flycatcher)
LONG-TAILED TIT
COAL TIT
BLUE TIT
GREAT TIT
NUTHATCH
EURASIAN TREECREEPER
PENDULINE TIT
RED-BACKED SHRIKE
GREAT GREY SHRIKE
MAGPIE
NUTCRACKER
COMMON STARLING
HOUSE SPARROW
SPANISH SPARROW
EURASIAN TREE SPARROW
CHAFFINCH
BRAMBLING
EUROPEAN SERIN
EUROPEAN GREENFINCH
EUROPEAN GOLDFINCH
EURASIAN SISKIN
COMMON LINNET
TWITE
REDPOLL (Lesser & Mealy — considered a single sp. on Swedish list)
TWO-BARRED CROSSBILL
COMMON CROSSBILL
COMMON ROSEFINCH
COMMON BULLFINCH
HAWFINCH
YELLOWHAMMER
REED BUNTING

Monday, October 21, 2013

proregulus

A Pallas's Leaf-warbler was seen yesterday close to the station. I confidently declared that “we would catch it tomorrow” — little did I know that it wouldn't take more than 10 minutes this morning before a combination of a well-placed net and a magic mp3 mix would have the bird in the mist-net. Perfectly executed precision ringing. Species 120 for the year.


Thursday, October 17, 2013

Hey there Mr Blue

I was running on autopilot and vodka fumes yesterday as I was extracting Robins and Wrens during the first net round. It was a dark and gloomy morning and, in the half-light, I went to extract a "robin" from the bottom shelf of net 4 in the lighthouse garden. The bird rolled slightly as I pulled the net towards me and... holy fuck, it had orange flanks. And yes, a blue tail. I held the bird and turned to Marcel, who was at the far end of the net. “Marcel, come here! Come here!” I shouted, with a generous sprinkling of profanity. Then I remembered what he had done with the subalpine warbler in spring, telling me to wait around the corner until the bird was extracted and I could enjoy the full impact. “No, stay there Marcel! Stay there!” I rearranged the bird in my hand so that only the tail was visible, then I lost it slightly. “It's blue! It's blue!” I shouted at Marcel. Of course he had no idea what was blue... until he came over and saw it for himself.


Sod's law dictates that good rarity weather equals crap photography weather, and yesterday morning was no exception. The sky was grey and low, and since the bird was caught in the first net-round there was an almost entire lack of sunlight in the lighthouse garden. Not that you need much light to document the salient features of a Red-flanked Bluetail but still... IOS 800, f5.6 and a 1/15th second shutter speed don't make for award winning photographs.

The bird was straightforward to age, showing an obvious moult-limit in the greater coverts (seven unmoulted).



The bright blue lesser coverts and the blueish tinge to the moulted greater coverts should allow us to confidently sex the bird as a male.


Svensson (1992) states that inside of upper mandible in first-years "yellowish, sometimes browner at tip" (with the footnote that this is taken from skins). It's the only ageing criteria given. I know that there is at least one British record of bluetail aged, from what I've heard, using the inside of the upper mandible. I've always been suspicious and yesterday's bird didn't help to relinquish those suspicions. I wonder how many people would age this bird as an adult if inside of the upper mandible was the only characteristic they were using.


I guess I can't post a blog post about a Red-flanked Bluetail with a photo of that tail.


Yesterday's ringing didn't stop with the bluetail. We caught nearly 500 birds, including 43 redpolls, 80 Common Chiffchaffs (mostly abietinus, some collybita and one good tristis candidate) — equalling the previous chiffchaff day record — and our first big Bullfinch of the year.


As if that wasn't enough ringing for one day, Peter Olsson, Albin and I opened 162m of assorted mesh-size mist-nets north of the garden just after dusk and, by midnight, we'd managed to catch a Long-eared Owl, a Moorhen and two Water Rails.


The owl is a 3+cy female. The secondaries show five reasonably broad dark bars.


Compare that to this first-year that we caught last year:


A closer look at the secondaries of last night's bird shows what appears to be a moult suspension limit in the secondaries, with the inner three or four moulted.


The outer three also appeared to be moulted, though the difference is subtle.


Critically for ageing as a 3+cy, both the old and the new secondaries show adult pattern; i.e. it is replacing adult secondaries with adult secondaries, so it must have undergone at least one complete moult prior to this one.

The primaries, or more correctly the primary coverts, also showed what appeared to be a moult suspension limit. You can see that the outer primary coverts are browner and appear more worn, though with owl's loose and fray-edged plumages I find it hard to assess wear sometimes.


According to the literature, adult birds moult all primaries so perhaps this bird will continue moulting primaries after migration. The suspended primary moult also explains the seemingly rather limited secondary moult (though per BWP, the range for retained secondaries is 0–6; this bird shows 6, so it might not be *that* limited).

The bird can be sexed on the overall rather brown-orange ground colour of the plumage, the dark face, and the orange-buff inner webs to the secondaries. Compare with last year's bird, a male, which has a whiter ground colour to the plumage, paler face, and white inner webs to the secondaries. I don't know if the primary pattern on the underwing is a consequence of age, sex, or both.