Thursday, 15 August 2013

Cherry Blossom and other darvics

Old friend red-7P8 Mediterranean Gull, aka "Cherry Blossom", back on Seton Sands tonight; this her 10th return, age at least 12 yrs. Tonight with 2 other adults (below) in just a couple of hundred small gulls at pre-roost a while before dusk. Presumably same also amongst 6 birds there last week (3 ads), along with another returnee white-32A4 (Johan's link not updated with last year's records yet) - a very interesting bird now in 3rd-summer but still with some dark in primary tips - per Olsen & Larsson 25% of males and 50% of females have some short dark markings on outer webs in 3rd-win.

Lots of colour-ringed Sandwich Terns reported recently, 3 per Dave at Seton on 15 August were juvs red-UFH, red-ULK from Northumbs (ringed Inner Farne 12 July and 31 July, respectively) and ad white-EVL (colour-ringed on the Ythan on 19/07/11, but originally ringed on Coquet Island, Northumbs on 26/6/05), and also seen there on 17 July this year, so presumably breeding there. Also one of this year's juveniles at Musselburgh on 18 July, yellow-EPK, ringed at Forvie on 13 June, and the first dispersing bird seen away from there. Prior to that we had a lime over dark green at Musselburgh on 15-16 July, this being the first ever resighting from the 2002 cohort at Forvie, and another of the lime over red flavour (2008 cohort) at Seton on 10 August. A colour-ringed adult at Seton red over blue is also a Forvie bird (details awaited). Thanks to Dave Allan for most of these, and ringers Ewan and Chris for prompt details!

A Little Tern at Musselburgh in early July had a blue colour ring, thus may be a South Gare bird.

Going back to last year also recently discovered that the ringed Roseate on Seton rocks then (Rosy special ring 32/V0) had been ringed on Coquet Island on 9 July 2006, by Tom Cadwallender. This might be the fourth Roseate control/recovery from outside Lothian, two previous were local birds from Fife whilst the third was a 1973 recovery near Drem (?) of a bird ringed on Coquet in 1969.

So the usual picture with terns from north and south moving into the Forth; some do continue overland, another common theme here is the nocturnal movement heard every year from mid-August, first heard this time at 22:30hrs on Monday 12 August with a couple of Sandwich Terns move SW over the top of Blindwells. Normally just Sandwich Terns but also occasionally Common Tern, perhaps others also pass over?

Finally ought to mention recent BHG darvics, George spotted Norwegian white-J9J9 on Fisherrow beach on 29 July, Ian had seen it at Eskmouth on 23 July. Also at Musselburgh on 2 August Dave got white-J3CE, an old one first ringed at Rogaland (Norway) in 1994, colour ring added there on 8/4/12.

red-7P8 still present to 19 August, together with 3 ads including the one below, outer primaries already moulted; comparing notes with Norman suggests a minimum of 8 different individuals (5 ad, 2 3rd-yr, 1 2nd-yr) in the last week of so.

Friday, 9 August 2013

The Seton Dipper

Having scoured the Seton tetrad for 6 years now I was initially sceptical when receiving a report of a Dipper at Seton Chapel in early July, seen by persons unknown, however an LBN appeal led to Murray contacting me with concrete info on his sighting - below the bridge in grounds of the Chapel monument when he was looking for the parakeet; I then followed up and found plenty of evidence by way of droppings at the small burn through the Chapel grounds - but no sign of the bird itself! Worse, the stream was running pretty dry and even at the best of times much of it is underground, including the last 500m from the House to the Seton Burn bridge on the coast road, just perhaps 100m of proper flow on that side. Minimum territory size for Dipper in good habitat is 100m, so it looked a bit marginal to support even a single bird for any length of time. Bird-aware residents at Seton House and the Seton Mill House had not seen it either, though there were also a few droppings at later location.

Too busy with atlas to look further in July but then Willie came to the rescue again refinding it at the nearby Blindwells Minewater Treatment Scheme on the other side of the A198 on 6 August. There is even less open watercourse on this side, and the sludge beds are now full of reeds way over head height, but there is a weir-like full length drop between the lower two tanks and exposed flowing water there which may well suit it very well. Photos here from Thursday 8 August, was content to rest a few minutes while I watched it, gently bobbing - NB, it is a juvenile of the species so a recent dispersal!

Why the interest? As far as I'm aware there are no historical records of Dipper here, and the nearest occupied territories are 4-5 miles distant on the lower River Esk and upper River Tyne. There are no waterways in between - and though the initial thought might be a displaced bird moving along the coast from the Esk in winter this seems pretty unlikely as it would need to fly inland at a random location to find the water it has now colonised (not relevant anyway to a juvenile). I'd guess it has more likely dispersed from the Tyne and been drawn in by the larger area of wetland including the adjacent Blindwells pond.

Do Dippers do this? The Price & Bock account of their American Dipper (Cinclus mexicanus) studies* contains some relevant and interesting information (p. 32) with two records of overland flight observed, one historical record in 1922 of a 400m movement across a Y in a river and their own sighting in 1971 of a bird displaced by others flying off overland and climbing to a height of 60m. They also refer to other movements between watersheds from their ringing studies that they attribute to movements overland, other routes along waterways being unfeasibly long and away from typical habitat. More relevant to the current case are references there to the observations in Jost's (1969) paper** on our European Dipper (Cinclus cinclus) documenting movements between watersheds by juveniles in the German Rhoen, and additional finding that adult Dippers make regular migrations across the high Swiss Alps where the lowest passes are over 2000m - Dippers caught in mist nests above the tree line! However all of these studies relate to higher altitude steep terrain, whereas the current case would involve a climb and descent of no more than 50m in 4+ miles. UK vismig records on trektellen show this species has not yet been logged on migration here, the only records being birds appearing at a Redmires reservoir which is connected to a waterway, but how many are we missing? Since posting Stuart has alerted me to his observation of a Dipper on the Cart Water in centre of Paisley flying off high above tenements.

So it turns out it can't be added to atlas as a juvenile. Plenty of genuine breeding activity still underway, thick with young birds along Blindwells margins with young Sedge Warblers (scolding parent below) and Whitethroats, I still live in hope that Tufted ducklings may yet emerge at Blindwells, the female having vanished again and the two drakes resident all summer. Also two families of young Bullfinch seen this week, and plenty gamebirds - see previous blog post. The atlas lives on for now!

* Price, F.E. & Bock, C.E. (1983) "Population ecology of the Dipper (Cinclus mexicanus) in the Front Range of Colorado", Studies in Avian Biolody No. 7. (download link)
** Jost, O. 1969. Über die bedeutung der wassersheiden beim ortswechsel der Wasseramsel (Cinclus cinclus aquaticus). [On the significance of water sheds in the movements of the Dipper (Cinclus cinclus aquaticus).] J. Ornithol. 110:71-78 [English sum.] (download link)

Wednesday, 7 August 2013

Atlas serendipity

Atlas and photos don't normally go so well together but this pure chance encounter (I stopped to check out a Wren) on verge of minor road south of Daneskine (NT56T) was quite remarkable - this bird was crouched very close just by the verge, surrounded by tiny chicks; I thought they would flush so I remained still and they were all like frozen statues for at least a couple of minutes, steadily I got closer and they began to relax, after a few more minutes I had to resort to the macro setting to photograph the chicks; whilst doing so one dozed off and others attempted to climb into the female's body feathers, then she began to nibble grass and commenced clucking calls with hints of the usual "go-chock" call at times. After five minutes a car came down the road and we had to leave, a remarkable encounter albeit with a naturalised species (or perhaps recent release).