31 March 2013

Spring Scandinavian Rock Pipits on Skokholm

I organised to spend a week on Skokholm 23rd to 30th March as a volunteer but didn't get on until Tuesday 26th due to the persistent easterlies. For the second time, I managed to team up with Mark Hipkin, who was great company, as were the new Wardens Richard and Giselle and the other Volunteers. The  horribly persistent, freezing easterlies killed off most migration but the birding was brightened by a chance to really grill a wide range of Rock Pipits Anthus petrosus, some of which appeared to show features of Scandinavian birds ssp littoralis. They turned out to be brilliant value. Bouncing ideas off Richard  and Mark made for a great learning experience. The first inkling of something interesting was when Mark saw a pipit near the Lighthouse where we were working. He described it as very Water Pipit-like with a pink flush on the breast and very clean white underparts. I caught up with what must have been the same bird a little later and was convinced it was a Scandinavian Rock Pipit, a male, at the brighter edge of the plumage range.  It showed a clear grey head, mantle and back tones with neat understated darker lines, contrasting darker brown wings, very clean white underparts with strong dark streaking extending from the sides of the upper breast to rear of flanks. The unmarked throat was pale pink, this striking colour extending onto the upper breast and was bordered by the flank streaks. I was convinced it was a littoralis bird, having seen spring birds previously on the east coast. Unfortunately neither Mark or I got a photo but it led to me spending a lot of time watching and trying to photograph Rock Pipits on the island. The bird below on East Bog was less stunningly obvious than the first, presumed male but is a good candidate nevertheless (accompanied by another very similar individual, which was just as convincing as littoralis).

littoralis bird, one of two very similar birds together

The same bird, very pale underparts.

Unlike general petrosus there is a quite marked difference between winter and spring plumage in littoralis (though petrosus can appear greyer and, paler below in spring and they can also, according to Richard's experience, acquire a 'peachy' wash on the breast, so care is clearly needed. The first, most striking feature of the bird above was the contrast between the brown wings and the grey back, mantle and head. On the whole, petrosus birds don't seem to show much of a contrast between wings and back, though in bright sunlight the back and mantle can appear somewhat paler and show some contrast with worn brown wing feathers, but then soft green tones are still very noticeable. The underparts are generally yellower or buffer with apparently more diffuse, smudgy streaking.  Birds with an obvious cleanly grey back and mantle, without any green or olive tones, and with very pale, whitish underparts contrastingly streaked on the flanks seemed a good prospect for littoralis.

Rock Pipits undergo a full body moult in winter but retain worn wing and tail feathers which become faded brown, thus emphasising the contrast. There is at least one newly moulted tertial in the littoralis bird in the photo below but being very dark still, it seems to me, creates a still strong contrast with the clear pale grey back and mantle giving an effect quite unlike usual petrosus birds. Other interesting features are the strong, bright supercilium and the apparently paler than standard, pinker legs; though this can be a reflective effect sometimes seen on petrosus birds in sunlight, it has been mooted as a feature of at least some littoralis birds. To me, this bird, its companion and the, even brighter, male seen the day before are pretty good for Scandinavian Rock Pipits. At least one other bird appeared to have a darker reddish tint to the bottom of the ear coverts and maybe a little in the upper flank but unfortunately was not photographed.

Other birds seen and photographed were apparently intermediate, maybe bright petrosus or dull littoralis   (there should be many more of these latter than the obvious birds I would imagine) but there was quite a bit of variety generally and a number were difficult to name with any confidence. Maybe there were just three littoralis birds or maybe a more significant passage through the Island during exceptional meteorological conditions, it's hard to be sure. Late March would be pretty much peak time for birds on the Norfolk coast as I recall. 

Here's a selection of some birds seen through the week:

Quite a pale individual

The same bird.

Another quite pale grey bird, back contrasting somewhat
 with brown wing, strong supercilium

White web to outer tail feather?

A very dark above but very whitish below individual.
It may have been bathing.

Bog standard petrosus.
And again.

11 March 2013

Northern Chiffchaffs

Siberian Chiffchaff (Phylloscopus collybita tristis) is, to my mind, a superb bird with an appearance and call redolent of autumn migration. It breeds in coniferous taiga forest  from the Ural region eastwards and is regular in Britain in autumn, usually late autumn and sometimes wintering here.  Identification has gradually developed over the years and had seemed pretty secure regardless of the counter-intuitive nature of the grey and white Chiffchaff problem. There have, however, been recent developments in the process and therefore a lot of further comment regarding the identification of Siberian Chiffchaff. Martin Garner on his 'Birding Frontiers' site has worked through the visual features using photos and the audio  features including sonagrams. There has also been related material in 'British Birds'.

What are the features of 'tristis'?

  • The standard features of Siberian Chiffchaff remain in place. Briefly these are: a basically brown and buff bird with weak olive tones confined to wings, rump and tail. The head pattern is important, having a thick buffy supercilium and tobacco tinged ear coverts. Bill and legs are clearly black.
  • The soft, even monosyllabic note with a sad tone (as suggested by the name 'tristis') remains pretty conclusive, if somewhat subjective without a recording.

The problem of grey and white individuals.

  • Martin Garner suggests that descriptions of grey plumage tones or brown/buff plumage tones may often be affected by light and posture variations, both in the field and in photographs. It may be that what is considered grey and what brown or buff is variable and extremely subjective and should not rule out 'tristis'. 'Grey and white' birds have generally been considered 'abietinus' or just 'unknown'.
  • Some birds are very grey (cf a bird on St Agnes in October 2011 - photo and comment from Alan Deans in a recent edition of  British Birds). These seem to be rare and are, as yet, something of an enigma.
  • 'abietinus' often looks very like 'collybita' but the plumage demarcation of this race appears to be very poorly known.
Previously presumed 'abietinus' 2012
St Davids Hd  (Mark Hipkin)

The variety of calls.

  • Martin Garner has suggested that various calls are possible for 'tristis' not only the well known call already mentioned. It has been suggested that 'tristis' may use a range of calls other than the characteristic calls of'tristis'.
  • 'tristis' can call with a higher pitched 'happier' tone or with a 'collybita' type call.
  • However presumably all races can give eccentric or unusual calls.

This is a very brief note  but the 'Birding Frontiers' posts and the papers in British Birds and elsewhere on these topics are thorough and fascinating. They deserve to be read in full by anyone interested in the topic.

Where have all the 'abietinus' gone?

One of the catalysts for the current discussion is a study from The Netherlands. Between 2009 and 2011, 41 samples from birds identified as 'abietinus' or 'tristis' when trapped were sent for mitochondrial DNA analysis. The results were startling, all were 'tristis' (though obviously these results have to be tested and more tests done). So where are the 'abietinus' birds? Two independent studies in The Netherlands and Britain have found no evidence of 'abietinus' DNA in autumn and wintering Chiffchaffs.  Maybe they are the real rarity, perhaps because they have a north-west to south-east migration pattern as with Baltic Gull? Could it be that the 'washed out' autumn Chiffchaffs recorded fairly routinely as 'abietinus' in Britain (including by me and noted elsewhwere on this blog) aren't 'abietinus' at all? Clearly this is all speculation but it does seem that answers may be on the way in the near future.

'Northern Chiffchaff' originally presumed 'abietinus'
Porth Clais October 2011

 Siberian Chiffchaffs in Pembrokeshire

The Pembrokeshire Report has occasionally mentioned 'Northern Chiffchaffs'  ('abietinus' and 'tristis')  but not with much conviction and I don't notice any requirement for descriptions. I don't know if this means there are no descriptions extant, if not it may be difficult to revisit previous records (a good reason for descriptions and initials with records in my view). Other 'tristis' records have not been submitted (including by me). It seems to me that full descriptions of possible 'tristis' should be required by the Bird Recorders, preferably with photos and, where the characteristic 'tristis' call is absent, also with sound recordings? Perhaps it would be best if all Pembs birders sent them in anyway.

The following individual was seen but not heard by Adrian Rogers and Steve Berry at Goodwick Moor in 2008, it would likely have gone down as 'abietinus' but what is it now?

Pale Chiffchaff Goodwick Moor 2008
Photo Adrian Rogers

The same individual

Plurals on Bird Blogs

Ibis or Ibises?
Is it Ibis or Ibises? The answer seems to be - it depends! There almost always seems to be two possible plurals for birds, the 'ordinary' plural and the collective plural. The 'ordinary' plural (Ibises) is for a number ie 'three Ibises at Marloes Mere'. The collective plural dispenses with the 's' (Ibis) but presumably should need a collective noun, so: 'a flock of Ibis at Carew'. That would appear to be the technical side of it. 


There's a difficulty though (isn't there always?). The difficulty is 'Usage'. Sometimes it sounds completely wrong to use the normal plural even when it is technically correct. Dunlin(s) and Whimbrel(s) are good examples. It feels really strange writing 'seven Dunlins' in fact it almost never happens as far as I can see. Usage has taken over. Is 'Snipe' an example of long term usage or is it an irregular plural? Either way 'Snipes' is just weird.

Where are we now?

It seems normal to write 'three Dunlin' but what about 'three Great Northern Diver'? Yuck! It seems we haven't got that far yet. Maybe if you need the adjectives preceding 'Diver' then it changes things? Well perhaps not that simple, I can't imagine many people writing 'three Robin in my garden' either. It seems the English Language will make its own slightly chaotic path through Bird Plurals but at least we can all be a bit right some of the time.

10 March 2013

Green Sandpipers wintering at Sealyham

Green Sandpiper is the wader most likely to be encountered in woodland and scrubby habitats usually, but not always, associated with water. At least for the last few years, Sealyham in the Anghof valley has been a regular wintering site for one or two birds which arrive in November and depart in April. The habitat consists of ponds, some of which are very silted up, a stream, gardens and woodland in a river valley. They seem also to use a stream on nearby farmland and maybe a slurry pit there. The photos below are of this winter's birds. There seems to be a male and female, judging by size difference. They are very wary and alert, usually a flash of white and black and a piercing call are all you experience. It's pretty magical around the garden though.

New Heronry

Grey Herons have bred on land we own at least once before. A single nest was noted by Graham Rees in 1986, then containing two young. There were indications of breeding this year with at least two birds seen at  garden ponds in February and early March. Kathy eventually found the birds on two obvious nests with a third half-formed above them. There is a possibility of disturbance, mainly due to business activities but we'll try to minimise problems as best we can. Everyone is being very co-operative. Hopefully I can update this post as the situation progresses.

Unfortunately one of the nests was abandoned in April. There appeared to be three eggs in the remaining nest which had hatched by 10th May. The photo below was taken on 17th May.

Not entirely sure how three became one, whether eggs didn't hatch or disaster struck two chicks but today (29th May) there is only one, well-grown youngster in the nest.