Monday, May 30, 2011

Starlings and bumblebees

Most of today was spent enticing Starlings into the garden. Eighteen were ringed in total of which all but three were juveniles. Starlings are extremely good at clambering out of the net and the total ringed represents only around 2/3 of the total number that went into the nets.

This one's a male, with a bluish-grey base to the bill and a (largely) brown iris:


And this one's a tatty female with a pinkish-yellow base to the bill and a pale ring in the iris:


The iris colour also works for juveniles. This one's a male:


And this one's a female:


Also caught were a single juvenile Greenfinch, a new 2cy male Blackbird, and a Dunnock.


This one's a real big boy.


It's also an adult. The wing feathers were in really good nick, the greater coverts are uniform right across the wing, and the primary coverts are noticeably broader compared to yesterday's bird.


And on the closed wing, the primary coverts are (relatively) uniform with a thin, tapering, black band on the tip; young birds tend to show a wider rather solid black bar - potentially useful for in the field...


Here's an iffy photo of a juvenile from a year or two back to illustrate the point.


And in non-bird news. Yesterday, whilst closing up the nets, I spotted a bumblebee in the garden. I've been doing a bit of work on bumblebees recently and, try as I might, it seem as if I might have accidental learned how to identify them. This one was Bombus hypnorum (Tree Bumblebee). The species only arrived in the British Isles a decade or so ago and is spreading northwards. Here's a map showing its distribution, up-to-date as of last Thursday, with thanks to Stuart Roberts at BWARS:

I've added a blue dot to show my record into what was previously an empty space. So, actually quite a significant record! The fact it was a worker that I saw suggests there's a nest somewhere nearby; so today, after the nets had stopped catching, I went on a bumblebee hunt around the garden. And look what I found...

Bombus hypnorum! There were several around the garden, both queens and workers, so it seems they are well established in the area.



Commonest, though, were these:


They're either Bombus lucorum (White-tailed Bumblebee) or Bombus terrestris (Buff-tailed Bumblebee). My Bombus-skills aren't yet up to separating these two species...

There were also a few of these:


Bombus pratorum (Early Bumblebee). Both of these are dark workers, lacking the usual yellow stripe at the base of the thorax.

The day finished with a wander through the local woods where a Kestrel was doing its best to catch Starlings and the wild-flower borders were in full bloom.

Sunday, May 29, 2011

Dunnock junk

Yesterday I battled north through bank holiday/half term traffic; with the M6 closed and seemingly every car in Britain on the roads, it was queue-central for most of the way. Good for roadkill spotting, though; a Grey Heron and a Mink were two quality ticks. Notable (live) bird sightings consisted entirely of raptors, with about 100 Red Kites over the Bucks/Oxon stretch of the M40 and a fair few Buzzards and Kestrels elsewhere along the route.

This afternoon, I stuck a net up in the garden and, despite the wind, managed to catch this Dunnock.


First, the easy part: sexing. Following on from this post, here is the little ventral 'tuft' I was talking about:


And a puff of air reveals the offending organ. Most definitely a male...


And on to the hard part. I doubt I'm the first to admit that I find Dunnocks difficult to age. Eye colour is useful for birds in autumn but once the eye has 'matured' things aren't so simple. This bird, though, *seemed* relatively straightforward to age. Overall, the plumage was pretty shagged. P9 (outermost[ish] primary, not visible in the picture) on both wings was broken and there were chips-ahoy in many of the other primaries.


Did I really just say chips-ahoy?

On the bird's right wing, S6 (innermost) had been replaced and contrasted with the five outer secondaries, especially the feather fring that was a much richer brown. The same secondary on the left wing hadn't been replaced, suggesting the feather was regrown following accidental loss rather than deliberately moulted. However, the feather appeared fairly old making it likely that the colour difference was genuinely down to it being of a different generation (i.e. adult-type rather than juvenile) rather than it simply being much newer and less faded. The longer length compared to the neighbouring feathers also supports this idea.


Additionally, and this is where things start to get a bit ropey, I'm fairly confident this bird had three retained juvenile greater coverts. The most obvious clue was the feather quality: 'looser' and not as solid looking as the inner greater coverts; additionally, there was a slight colour difference (similar to in the secondariness but much less pronounced). The pale tips on the outer web of the feather also seem in agreement with that the colour and feather quality were suggesting; they extended further up the feather and ended rather sharply at the base. This compared to the smaller and smudgier-looking pale tips on the neighbouring greater coverts. The outer greater coverts also showed fairly obvious pale spots on the inner web of the feather and the black in the centre of the feathers was more solid. As can be seen, pale spots do become larger and more obvious moving away from the body but the rather sudden change in the pattern on these feathers suggests it is not merely down to this.


The same differences are also visible on the closed wing, though only two of the outer three (presumed) juvenile greater coverts are visible.


So, it looks like the bird is a 2cy, and neither alula nor primary covert pattern disagree with this conclusion. Thoughts and comments on the subject welcome!

Friday, May 27, 2011

Falsterbo ringing recoveries online

I'd love to say I haven't posted anything for the last three weeks because I've been so busy out in the field, away from internet, birding dawn to dusk. But I haven't. I've been in west London with nothing at all interesting to say. Except that I survived the end of the world and that yesterday it hailed.

Anyway, now I do have something really interesting to say. Måns Karlsson sent me some exciting news about all of the ringing recovery records that are generated from birds ringed at Falsterbo Bird Observatory in southern Sweden and subsequently found elsewhere. Here's what Måns says about the new feature on their website:

Hello!

This week Falsterbo Bird Observatory launched a new feature on our website, an interactive map showing recoveries of birds ringed at Falsterbo throughout the years. Everything is available in English and you are free to search on any species, age and sex. Also, the three oldest birds and the three most distant recoveries are automatically listed, you can choose to show the average position depending on season and much more.
Please have a look at www.falsterbofagelstation.se, just scroll down a little when you're at the newsfeed and the link is right there. Or click on "Recoveries" in the menu bar at the top!
If anybody has any feedback or questions, please feel free to contact FBO.

Sincerely,

Måns Karlsson, Falsterbo Bird Observatory

Some of the recoveries and the whole site is well worth a look.

Monday, May 09, 2011

Plastic foot of doom

Here are three reports that caught my eye today:





The first one is funny for pretty obvious reasons; the second because Twitchers' Gate is a really lame place name; and the third because some people still seem to be convinced that this bird might wild (or at least 'of unknown origin'), despite it looking considerably less than Scandinavian!!!!!!!!



Oops, sorry, my fingers must have got stuck simultaneously on the shift key and the 1 key. My bad.

Owl photo 'borrowed' from Penny Clarke's blog.

Sunday, May 08, 2011

Singing male Dunnocks?

Hardly a headline to pull excited passers-by in off the street.... And I'm not sure the body of this post is going to get any more interesting. Although it might get some interesting Google search results. Anyway, I'll start with a quote from the always wonderful Sound Approach:
I remember reading a beautiful introduction to bird sound in The handbook of birds of the world 6 by Baptista & Kroodsma (2001), when suddenly I learnt that female Alpine Accenotors P collaris sing to attract males. I had recorded the song of the species in the French Pyrenees and not imagined that it was anything other than a male. Later, on recounting the song to veteran Dutch birder, Gerald Oreel, he said "you do realise Dunnock is the same?".
Ever since I first read it, that bit if text has intrigued me. I always took it to mean that it was only the females that sang. After all, given everything else that's up with their breeding behaviour, that wouldn't seem too out of the question; and ever time I was in company and heard a Dunnock sing I'd smugly say "that's a female, that is".
Nevertheless, I'd always wanted to prove this first-hand for myself - not because I doubted what was written, just because that's the sort of person I am.



It's easy enough to find a signing Dunnock; quite another thing to work out if it's a male or a female! I came up with a cunning plan. I'd do my best to catch as many of the local Dunnocks around my garden as possible, ringing all of the birds that were definitely female on left leg and all of the other birds (males and unsexed birds) on the right leg. Then all I needed to do was to watch a singing Dunnock, see which leg the ring was in, and if it was the left leg: bingo, I'd got myself a singing female Dunnock. Unfortunately, I only ever managed to catch three Dunnocks; one was a male while the other two were caught early in the year and had to be left unsexed. You see, Dunnocks can only really be reliably sexes in the breeding season. Females develop a brood path, an area of bare skin on the belly used for incubating; males develop a large 'cloacal protuberance'. That's a big willy, to you and me. And by most bird's standards, a Dunnock's "C.P." is massive, which gave me an idea for a plan B.
Usually, a bird's feathers are rather smooth and continuous in contour; any protruding bits are hidden away under the layer of feathers. However, compared to most other birds, male Dunnocks are a little bit... bigger. Think of it like a well-endowed man in a pair of hot pants; things poke out. With good views during the height of the breeding season you can just make out a spiky tuft if feathering that breaks the surface of the ventral region. That's his cloaca, and that's proof that he's a male. So, finally, a way of sexing Dunnock in the field.

So, why am I telling you this? Whilst camping in the New Forest last week, there was often a Dunnock singing in the small bush behind the tent. One morning it gave particularly good views as it hopped about on the floor, singing as it did so. And there, poking out of its vent was a small spiky protrusion of feathers - it was a male! And it was singing. Suddenly, everything I thought I knew about singing Dunnocks came crashing down around me.

Where had things gone wrong? Was what had been written about Dunnocks wrong? Or was it simply that I had read it wrong? A little bit of Googling sorted things out. A Google search at the beginning would likely have been the simplest way of doing things, but chasing singing Dunnocks round trying to catch a glimpse of the private parts is far more fun. It turns out that I had read the text wrong; the message I should have come away with is not that female accentors do all the singing but that female accentors also sing. Now then, I wonder if you can hear the difference between male and female Dunnock song....

For a bit more, see here (original Alpine Accentor paper), and here (Dunnock paper).

P.S. Answering my own pondering from above, there's a short note in BB from 1970 entitled "Song of female Dunnock" (British Birds 63, 179–180) that states "With practice, it was possible to distinguish her song from the male's: it was shorter and
the notes seemed to be arranged differently". I really should read through the literature before thinking out loud!

Monday, May 02, 2011

The weekend that was

Friday: the day of the wedding. The wedding. After reading plenty about how many people were avoiding it etc, I'll happily admit to getting up and watching it live on the beeb. I thought it was great, the whole thing (although I did go for a shower while the service formalities were going on), and so nice to see so many people out on The Mall. I will say, though, a) the shock that they kissed TWICE was perhaps a little overplayed, and b) the comment "William certainly is a good driver", was, well, silly. He drove at 20 mph down a wide, straight, empty road... I think my sister could manage that, and she crashed into a parked car...
Anyway, I digress. After a brief trip into the city centre, along an uncharacteristically empty A40, I headed out west towards Hampshire. The M4 was equally as empty, partly due to a rolling roadblock about half a mile behind me to allow a departing wedding guest to speed through on their way to Heathrow; twenty police riders and a shadowing Range Rover suggested a foreign royal, perhaps. Friday evening was spent in a pub in north Hampshire, getting annoyed by how loud the house band were playing and pointing out that the Wills and Kate flags were the wrong dimensions. Can one be middle aged at the age of 23?

Saturday morning Joe and I headed down to Hurst Castle for some early morning seawatching. Or some early morning seawatching for Joe, I should say. Hampshire, as nice as the county is for birding, never really strikes me as a prime seawatching location; there's a big lump of chalk in the way.

So, I left Joe to stare at the Isle of Wight for a few hours (notching up a couple of Poms and four Velvet Scoters) while I took did some birding on the marshes.
A buck Roe Deer was out on the shingle spit; with the arrival of some early morning dog walkers, it decided to make an exit, swimming across the tidal lagoon and on into the arable fields inland.


With only three and a half legs, perhaps it found swimming easier than hopping...


Also on the tidal lagoon, perhaps not unexpectedly after last week's movements, were a small flock of Bar-tailed Godwits. Most of the males were looking lovely in their breeding plumage.


Onwards to Pennington Marshes. A couple of Lesser Whitethroats were singing along the cycle track and my first Common Swift of the year flew over; this Little Stint was on Fishtail lagoon.


Just as I was walking away, a flock of ten Calidris waders flew towards me... nine Dunlin and, ooh, that looks like a Curlew Sandpiper. I watched as the flock past me, expecting to see a gleeming white rump* in the middle of the flock. But I didn't. Instead I saw a rump that looked a sort of streaky greyish. Admittedly at this point the flock were flying into the light, so views weren't the best, but I was quite sure the rump wasn't white. Thankfully the flock landed further along Fishtail lagoon and off I scuttled for a better look. Sure enough, there were nine Dunlin and a perfectly fine-looking fresh breeding-plumaged Curlew Sand. I watched them for a while and eventually they flew from one island to the next - and the rump was indeed barred. Odd. However, a quick look on my phone revealed that actually this might not be all that unusual after all - as the old tagline goes, always discovering!

*I'm using the word rump here in that commonly-used but often incorrect "ooh look at its white rump" sort of way, rather than the techinically-correct "feathering between the uppertail coverts and the back" sort of way.

Other waders included two Knot, a breeding-plumage Sanderling, a male Ruff, and quite a few Turnstones. A drake Garganey was on Butts lagoon while Sandwich, Common & Little Terns and Yellow Wagtails passed overhead; and several Dartford Warblers were in the gorse bushes along with masses of Common Whitethroats..


Up in the New Forest things were quite quiet, though we did manage to find several Wood Warblers, a handful of Redstarts and a Crossbill.


New Forest pony:


New Forest nuisance:

In the forest - out of control
Worryingly, I saw more than one car with one of these stickers.

Evening meal consisted of fish, chips and Fosters; thankfully the chip shop's food was a lot better than its grammar:


We finished the day at the very pretty though rather birdless Hatchet Pond; a pony using my wing-mirror as a scratching post, almost breaking it off in the process, was about as eventful as it got.


Sunday morning we headed back to Pennington Marshes. Four Little Stints were on Jetty Lagoon and again there were plenty of Bar-tailed Godwits. Small groups of Whimbrel were also passing over and occasionally landing in the fields or on the marsh.



Next, we headed to Blashford. Hell-on-Earth on most weekend days; we were expecting a bank holiday Sunday to be even worse.

But it wasn't. That is an empty Woodland Hide. Completely empty. Mind you, we saw nothing more exciting than a Great Spotted Woodpecker from there, but even so. I've never seen the place so quiet. A Garden Warbler and a Hobby passing over were both new for this year.

Joe is county yearlisting this year - and doing a good job of it, too - so, when news of a Wood Sandpiper broke at Farlington Marshes, we headed east. Joe wandered off to the furthest point of the reserve to view the sandpiper while I entertained myself with these Blue-tailed Damselflies. I was particularly interested in the different colour morphs (for exciting reasons that should become clear in soon). All of the different colour morphs/forms were present: young (green thoraxed) males; mature (blue thoraxed) males; typica (male-like) adult females; rufescens (pink-thoraxed) imature females; rufescens-obsoltea (yellow coloured) adult females; infuscans (greenish-thoraxed) adult females; and some really attractive violacea immature females, with bright purple thoraxes.

rufescens female:


mature male:


Back in the New Forest and taking a wander across some of the heathland, more Dartford Warblers along with a few Stonechats were about the only birds on show. A Cuckoo flew over and was the first one seen of many heard. Highlight for me came from looking down, not up - something slithered away from my right foot and under a bush. It was small and brown and I was expecting it to be a Slow Worm; peering into the bush, though, revealed a neat pattern of dark diamonds along its back: an Adder! Amazingly my first snake of any sort in the UK. By the time my phone was out of my pocket it had slithered deeper into the bush and out of sight.
Again, evening highlights were provided by New Forest ponies; this time a gang of hooligan horses running amok on the camp site and swiping food (literally) from peoples barbecues.

And this morning. Well, nothing much to report. We woke to the sound of a Lesser Spotted Woodpecker drumming on the edge of the campsite, with another off in the distance. Then it was back to London - again on alarmingly clear roads, passing someone driving a boat (seriously, an actual boat with wheels) along the A303 on the way!