Monday 27 August 2012

Wknd 25-26 August

Large numbers of seabirds remain in the Forth, Dave mentioned "Masses of Auks, certainly in the thousands, on the sea between Gosford and Seafield" on Friday. I had estimated 850+ off Cockenzie that day, c. 60% Razorbill, many ads + young or groups of 10, 20 and even 50, some mixed with Guillemot. From the reports it seems the only counts in excess of 500 for feeding flocks in last 30 years or so were 2140+ Guillemot 19/8/04 (DA) and 580 Razorbill 29/8/07 (HEMD), both counted from Musselburgh.

This current concentration in the Forth may not be a coincidence given the recent influx of terns which presumably home in on good feeding and can rapidly move to better areas if needed? Consistent with this hypothesis there have also been great gatherings of gulls and Gannets at shoals offshore, along with Shags etc. I'm a novice at fish ID, and auks usually consume prey underwater, but in those brought up for chicks have noted what seem to be sandeels; have seen Shags/Cormorants eating pipefish, flatfish and probably sprats. One study* of Guillemot diet off western Scotland found a marked seasonal change:

"In April and June the diet was mainly or substantially composed of sandeels Ammodytidae (overwhelmingly the lesser sandeel...). In contrast, sandeels were absent in August and November. Diet was also considerably more diverse in the later part of the year, ... when various clupeids (sprats and herring) and gadids (whiting, poor cod, and cod) were the major components of the diet.

This pattern may partly explained by the biology of the prey species. Sandeels bury themselves in muddy or sandy substrates for much of the time during late summer/early autumn to late winter, and so become less available to Common Guillemots. Sprats are generally found offshore in spring and summer, becoming abundant closer to shore in late summer and autumn (Jones 1976). As a result, they become more available to Common Guillemots in later summer, at the same time that sandeels are becoming unavailable."

[Postscript: Bryan on LBN confirms the gulls and auks are indeed consuming sprats, he also comments on the "strange sound" we hear floating in from the sea of the combined begging calls of the many young auks, it is actually a magical noise and the first time I remember hearing this here!]

Other ad hoc sightings: 1260 Herring Gull (96 juv) on Seton Burn/shoals immediately offshore Friday early afternoon; 1 juv Arctic Tern on burn; 1 juv Puffin amongst 660 auks in Forth on Saturday; 23 Red-necked Grebe off Longniddry Bents on Sunday afternoon, roughly half still in summer plumage (one shown above, normally too far offshore!), 5+ more beyond Ferny Ness but poor visibility; ad Roseate Tern and ad Med Gull on rocks east of c/p 2, the latter was still there at dusk to roost (unringed); 110 Sandwich Tern in Seton roost Sunday, and a Common Sandpiper past, but no Meds :(

Only one atlas success with Woodpigeon nest found at Longniddry Bents.

Monday - still 3 Swift feeding over house amongst House Martins on a muggy still evening. 36 House Martins over the house a couple of weeks ago must have included birds from elsewhere in the village, seem to have done well this year and still entering nest on house opposite today (27 August).

* Halley et al (1995) "Seasonal and geographical variations in the diet of Common Guillemots Uria aalge off western Scotland", Seabird 17:12-20.

Friday 24 August 2012

Night Herons

Update on zoo Night Herons - in February Geoff had found both of the known survivors still in residence, these free flying birds were once thought to be extinct (back in 2007, and BS3); there is now a new picture of the red/green left bird on SOC gallery; the published longevity record for this species (hoactli race) is 21 years but this ancient bird seems now to have reached 25yrs+ (2010 summary, my own poor photo from that date above).

[Post from November 2011: another out of area item, alerted to this Night Heron story by Ian, bird recovered from Dungarit near Stranraer (where mobbed by Buzzards).

Originally from Edinburgh zoo, this is my understanding of the colour-ringing regimes adopted there 1984-2004:

* 1982-1987(8) - red right, 3 colours left
* 1989-1995 - red right, blue/yellow left (some blue/red left 1994)
* 1997-2004 - ad hoc 0, 1 or 2 red, blue/yellow bands either leg

So this individual would seem to be one of the last batch, thus probably rather younger than the two survivors at the zoo itself (one each from the two earlier ringing regimes).]

Sunday 19 August 2012

Wknd 18-19 August

Arrived at Seton prom on rising tide Saturday afternoon to find the Wrecked Craigs rocks covered in birds, 500+, with a large influx of terns, mainly Common Tern with 240+ (28 juv) [previous high count here was 20 on 3/9/06, can't find any bigger in Lothian database either!]. No great surprise with huge numbers being reported from Aberlady though. Also still Sandwich in numbers (87, 29 juv), and, the ad+juv Roseate were back again.

Photos of ringed birds below, had just completed reading the Sandwich Tern metal ring (DD61480) when I spotted the Roseates again close in and realised I had a perhaps unique opportunity to decode their own inscribed metal rings "Roseate Specials". Tough work reading the tiny letters and on tenter hooks as passers-by flushed nearest terns off rocks, but the photos obtained seem to have enough at least for the adult (and I'm hoping there are limited known combinations of this year's successful breeders, wherever they may be from). Coquet had 71 prs rearing 75 chicks this year, which is one obvious possibility [post-script - subsequent confirmed as a Coquet bird 32/V0 ringed 9/7/06]. The only 2 previous ring "controls" for this species in Lothian both derived from Fife, likely at former breeding sites on inner Forth islands, so it would be a good one if these can be confirmed as out-of-area visitors.

An ad male Peregrine also went throo W at one point flushing all the terns, but they settled again. 2 Common Sand amongst the waders which I did not have time to count. In the midst of all this was also trying to log and photo the many Shag rings, got 20 different today/ystdy but with an overlap which were same on both days of just 6, showing the sort of turn-over. Probably more than half of young Shags now sport a colour ring (darvic), not very long ago even to get a single read was a highlight of a day's birding but now reading and documenting them all has become quite a job!

The legibility also varies enormously, sparse black letters on white are relatively easy, whilst dense letters on green, e.g. code green-XDN, are really tough. Some of this illustrated below, ZTC on green is OK but initially with poor view thought it was ZIC, also ZXZ was a tricky combination, depending on the orientation an X can often either look like a V or an A. Shags here almost always at same range of 300m, once the tide rises to cover the last rocks they go out to sea, going onto the shore tends to flush them (though people regularly do!). red-TJI on its favourite rock is an old friend, a 2009 chick from Isle of May, thus 3rd-sum~adult plumage, also seen here last summer.

At the other end of the spectrum, got breeding confirmation for Feral Pigeon at Seton East, though farmer was planning to evict them, nevertheless 51st confirmed in NT47C (now just 4 more expected: Gropper, Mistle Thrush, Stock Dove & Greenfinch).

Sunday - not quite as many birds at Seton, got only 4 Shag darvics with only one new. Around WeBS the main highlight was abundant young of sparrows and hirundines; at East Fenton, a great cloud of sparrows rising from dust baths and cereal back into hawthorn hedge, slowly trickling back over several minutes but on every alarm from the Swallows over nearby farm all rushing back to cover. Never got a complete count but estimated at least 300, 80% plus were Tree Sparrows, mainly young; previous high counts in 2007 & 2009 were only c. 60 (more in winter flocks). Many more House Sparrows round the farm itself, plus 180+ House Martins perched all over - also mainly juvs but not all locally produced (just 3 UN there). Quail still singing there too, regular bouts audible from fields towards Chapel farm. Added a few breeding confirmations, spanning Coot, hirundines, Willow Warbler, Whitethroat and Goldfinch, all on basis of (likely local) fledged young.

In the evening, while doing the "hedge" (grown 10 feet in 5 years!) in a nice cooling rain Swifts suddenly appeared overhead, 45 went SW in a silent procession, just the odd abrupt high-pitched "chik" being uttered - perhaps their final appearance here? Same hedge (c. 15m long) contained no less than 3 Woodpigeon nests with eggs, though only one is active. After blaming the kids then suspecting the Blackbird now I've discovered who has been rooting out all our flowering stonecrop below the kitchen window, fresh nest base made out of it!

Friday 10 August 2012

Wknd 11-12 August

Starting another new post for these images of white-32A4, a 2nd-sum to 3rd-win Med Gull, ringed as a chick on De Kreupel Island in Netherlands on 24 June 2010, on Seton Sands rocks in late evening sun on 9 August. Still plenty black in outer primaries which led to me initially ageing it wrong as a 2nd-win, however per Olsen & Larsson 2nd-sum have P7-10 varying black, exceptionally to P5, but moult of outer primaries is typically only complete by mid Sept, 10% by mid-Oct, so even though it has dropped P6-P7 the retained black is OK for a "3rd-win" ("win" by virtue of complete moult of head). Extent of black stated to be variable, with some males just weak dark grey markings P9/10, so this bird perhaps a female? Certainly will be more careful with claiming 2nd-win before primaries are moulted in future!

An interesting bird given the Loch Ryan (D&G) and Irish sightings too, clearly establishing Lothian coast as a passage route from breeding grounds, presumably from around IJsselmeer area in coastal Netherlands, to the Scottish West coast and beyond; however, the April 2011 sighting is well into breeding so perhaps this bird summered in Wexford area that year, as a 1st-sum? Anyway, presumably these birds generally cross the North Sea west post-breeding, then "coast" up along the east coast; supporting this theory white-32A1 (ringed as chick on same day, so presumably a near relation!) was logged at Newbiggin on 26/9/10, 3 months after ringing; a nice account of this and other Northumbs birds is available in NTBC Birds Notes 3.

Also at Wrecked Craigs, another light-green over red (right) adult Sandwich Tern (in 145, 48 juv); as per sightings in May and early July (2), this is one of 300 chicks marked at Sands of Forvie in 2008. Can't remember when last at Seton without colour-rings to read - quite a job to keep up with reporting and documenting them all!

View looking the other way at Seton, Mute Swan now resident since spring 2009, has drawn in a few passing birds in recent days and once seen a good mile offshore (3/8); alone again now - no wonder as was seen chasing off an interloper yesterday in aggressive busking display, presumably wants to keep its free hand-outs of bread for itself!

Longniddry shore at dusk - another 65 Sandwich Terns here:

Friday morning - Shags blue-CCI, blue-ZLP, green-SPJ and red-TLZ. The former is an old friend (ringed Isle of May 14/7/98) and the first ring I read here back in Nov 2006, but did not confirm code until resighted in Sept 2009! 2 Sandwich Terns light-green over red and one white darvic (ELT?) in 153 birds. Also first Arctic Tern of the autumn, 2 ads + juv, also 6 + 1 Common Tern. An unusual sighting of an adult Great Crested Grebe just offshore.

Friday evening, another glorious sunset and an apparent 3rd-win Med Gull on Seton Sands rocks (could not see legs to confirm same), also two very different looking adult Med Gulls, one larger bird with blocky head all white but for a tiny ear dot, the other a very small individual (perhaps same as last week July?) shown here:

Saturday - out of the area on trip to Montrose, bit of a busman's holiday as arrived to find beach covered in terns and gulls, c. 3k; after some scrutiny estimated 300 Common Tern (many juvs), 280 Sandwich (white darvic and red-ESF shown below, plus red/green and light-green/blue Forvie chicks), 38 Arctic (c. 12 juvs); gulls breakdown c. 1600 Herring (many plunge feeding in shallows), 300 BHG, 190 Kittiwake (many juvs), several Common Gull (1 juv), 3 LBB, 1 GBB. No Meds though :( Photo of a small slice of this gathering below, the Arctic Tern band is along the middle. [PS - red-ESF was ringed as an adult on the Ythan on 3/8/11 and seen thereafter at Girdleness on 27/8/11).

Dusk Sunday - no change with 2 ad Med Gulls and apparent 3rd-win, but could not see legs to be sure latter is same white-32A4. 3 juv Common Gull in 320, 22 juv BHG in 420, 85 Sandwich Tern.

Monday morning - ad+Juv Roseate Tern on Wrecked Craigs rocks, a brilliant species, marvellous calls too, and long-awaited patch tick. Ad ringed both legs, tall metal ring right leg, BTO metal left; juv ringed probably only metal left - this type of ring standard in Europe (& N America) - unfortunately futile to try to read the tiny stamped digits at range 300m! Also Shags including red-TJI (3rd-sum, ringed Isle of May 20/6/09), red-LLZ (ad, ringed Isle of May, 19/7/05), red-CFZ (also here 10/9/11), green-Z*D and a couple of blue.

Tuesday - Shag red-LLZ still, this Isle of May 2005 chick previously seen here various dates in Aug 2009 and Oct 2011, but also spotted at Aberdeen harbour in September 2009 just a month after being seen here.

Tuesday evening - arrived at Seton a bit late, half an hour after sunset one ad Med by the burn and 360 moulting Eider floating on sea at burn mouth.

Sunday 5 August 2012

Wknd 4-5 August

Started a new post but more of the same really, this yellow darvic 3rd-sum GBB has returned to Seton - seen previously in Seton harbour on 22 March last year, and at Wrecked Craigs on 25 July, a Berriedale chick originally ringed on 22/6/09. Indeed given its return it looks likely it is one and the same as a yellow darvic juvenile I saw at Wrecked Craigs on 16 October 2009 in its first autumn - it will hopefully return for years to come as per its cousins orange-1787 and red-7P8 which are still here.

Also Shags blue-ZXZ, green-USS and red-*ED.

Early evening - 13 RNG, mainly off Longniddry Bents and well out into Gosford Bay, also 451 moulting Eider, 197 Velvet Scoter and a couple of Puffin; c. 400 large waders disturbed and wheeling over Craigielaw then whiffling back, mainly Barwit.

Swift movements getting underway, also 75 over Oldcraighall ystdy and 25 screaming over Seton Burn of all places last night.

Saturday - excursion to New Winton in effort to plug some of those annoying atlas gaps, slow going but finally found a tiny juv Dunnock in wood behind village and also confirmed Wren - umpteen trips to New Winton for Wren in winter and breeding but hopefully that's it!

On way back conditions became very atmospheric with thunderclouds and mist rolling in, this scene at Cockenzie harbour. 2 ad Med Gulls on Seton Burn, also 41 LBB (high count) of which two were very dark. After some consideration believe these are intermedius. Checking Lothian database/LBR to 1980 it seems we have records only for Oct-Mar, one each in April/May, except for a small flock in Aug 1993, but perhaps under-recorded?

Sunday - went up into Garleton Hills to add hirundines to remaining atlas gaps, generally productive confirming Swallow, House Martin, House Sparrow, Tree Sparrow, Goldfinch & Linnet to NT47Y (Byres/West Garleton); Coal Tit, Willow Warbler, Chaffinch & House Sparrow to NT47T (Lochhill), plus a few others confirmed and upgraded. Many juvs amongst 40+ hirundines over crop at Jinging Hill, surely there are few farms in this area without fledged young now and many more gaps could still be easily plugged!

Monday - yellow-E29 GBB still at Seton, along with Shag white-HLL (and two red darvics), also Common Sandpiper.

Tuesday - never ending rings, this time a new Sandwich Tern, white-ELT, ringed as an adult on Ythan on 30 August 2010 and not seen since (above). Amongst 105 Sandwich Terns on Wrecked Craigs rocks as tide came in, 31 juvs (only 2 metal rings in those). Interesting comment from ringers that numbers had dropped drastically overnight to Tuesday, 2000 to 400 at Fraserburgh - the night after migrants were heard S over our house in Longniddry. Also had first Common Terns back this week, just a couple with their juvenile, though one adult apparently ringed on both legs (?); nothing to compare with the vast numbers at Muss/Aberlady, neither any other tern species.

Also there Turnstone numbers increased to 39, with first two juvs amongst them, 31 Golden Plover included 3 juvs. Common Sand again. Finally some confiding Ringed Plovers as per below: