Grafham Water 21 July 2012

A long morning on the dam and around the lagoons in warm almost anticyclonic weather...


The migratory cycle moves forward another notch - 2 Ospreys this morning an adult roving widely over the reservoir until it flew off strongly south at  09:55 then a different adult bird with distinctive primary moult appeared over the dam at 10.20 before flying off ENE and putting all the gulls up over Diddington Pit. A single adult Hobby over the model farm again; a Common Buzzard displaying over Diddington Wood; 16 Yellow-legged Gulls initially around the dam then dispersing; a lone adult Common Gull dropped in from a great height to rest and bathe near the dam followed by a group of 12 high west; a distant adult Caspian Gull was beyond photographic range perched on a buoy in the heat haze late morning;  9 Green Sandpipers on the lagoons; 1 adult schinzii Dunlin on the dam; 3 adult Redshanks in form the north went off west; 1 Whimbrel over SW at 11.15; 16 Yellow Wagtails was a higher count and presumably included local adults & juveniles as well as early dispersing adults from elsewhere; family groups of Barn Swallows (total c40) , Willow Warblers, Linnets (total 18) and Yellowhammers (total 11) were a welcome sight; a male Reed Bunting near the dam was a probable migrant. Excellent showing of Ringlets at the lagoons a good season for this subtle and attractive insect this year.

adult Osprey

adult Willow Warbler amply illustrating the rationale behind
the traditional noun leaf warblers applied to this genus

schinzii race Dunlin - upperpart fringes now worn exposing the black feather centres with limited cream/buff fringing

Holme Fen & Grafham Water 16 July 2012

Inspite of the low clouds scudding across from the south-west mixed with intermittent rain rather than the insect friendly warm sunny weather that one would hope for in July. I manged to have a reasonable morning at Holme Fenn NNR.a serene block of habitat which is is the largest natutal birch woodland in the country.

The avian highlights were 3 Marsh Harriers (1 male) over adjacent arable land; a female Garganey on the mere and a nearly trod on male Quail which literally jumped then flew over a small dyke into a wheat field, guaranteed to be my only Quail sighting of the year other than those hung in Borough Market.
Stopped off at Grafham on the way home at lunchtime, with the rain becoming heavy and persistent, little to be seen apart from 5 Yellow-legged Gulls, 2 Green Sandpipers, a lone Dunlin at the lagoons and small numbers of Swifts and hirundines struggling to feed...

juvenile Blackcap

Grafham Water 15 July 2012

A cool wnw breeze this morning felt more like September than mid July.
A fairly quite morning the highlight being a summer-plumaged Knot that circled the middle of the reservoir mid morning then flew off east; 3 Green Sandpipers on the lagoons; 5 Common Sandpipers, 4 Lapwings high south; 8 Yellow-legged Gulls (3 ads, 1 4th calendar year, 3 3rd calndar years and 1 2nd calendar year); 10 Common Terns (all adults); c 50 Swifts and juvenile Yellow Wagtails now up to 7 in number along the dam road.

Large Skipper on Self-heal - out in numbers today

Little Paxton - balcony birding 11 July 2012

A couple of hours on the balcony in nice weather this evening until heavy rain set in...

A single adult Hobby, 2 Black-Tailed Godwits through south, 4 Oystercatchers over, 3 Redshank along the river, 8 Common terns and a group of c60 House Martins were the highlights; notably few Swifts around this evening compared to just a week ago and I suspect that many are already drifting southwards...

Grafham Water 9 July 2012

from 0600 to lunchtime along the dam and around the lagoons, largely overcast with a fairly fresh westerly


An early autumn pulse of sterna Terns came through at about 9.00 am 16 Adult Common Terns with more surprisingly a single first-summer Arctic Tern, the flock appeared over the dam then flew off strongly west before I could get any shots of the hyperactive and generally infrequently seen first-summer Arctic...


Waders were restricted to 5 Common Sandpipers and 3 Green Sandpipers; 14 Yellow-legged Gulls (5 adults, 1 4th calendar year, 2 2nd calendar years, and 6 3rd calendar years); an adult Hobby over the model farm harassing Swallows added a touch of dash and class to proceedings as they always do; 4 Red Kites was a good count; a male Cuckoo was also at the model farm, a single Turtle Dove at the lagoons and the first three juvenile Yellow Wagtails along the dam were welcome sights. A second brood of 9 Gadwall ducklings at the lagoons looked to be doing well. 

Cuckoo

Grafham Water 7 July 2012

Did three and a half hours early morning along the dam and lagoons area in initially murky then clearer conditions with a light ESE breeze..


An Osprey flew east at 09:15 ish; waders continue to pass through 8 Lapwings flew south, a Ringed Plover arrived from the north, 6 Common Sandpipers (4 along the dam & 2 near the yacht club), 8 Green Sandpipers on the lagoons and a couple of Redshanks; larids were represented by 7 Yellow-legged Gulls (2 ads, 4 3rd calendar years, 1 4th calendar year), 17 LBB's just 3 GBB's and an interesting 3rd calendar year gull that was most likely a Caspian Gull (see below). 
Otherwise 6 Little Egrets (3 juveniles), 6 Common Terns and an adult Spotted Flycatcher near the dam were the highlights. An early passage of Swifts south c.250 was indicative of the poor breeding season that they have doubtless had and for similar reasons most warbler species are still singing frequently including 2 Cetti's at the lagoons; 3 adult male Yellow Wagtails were carrying food at the north side of the dam. 

Garden Warbler

Little Egrets 

An interesting Gull

This gull was near the dam in the company of Yellow-legged Gulls and LBB's early morning only after which it flew off south. Aged as a third calendar year bird undergoing it's second complete moult. This is probably the most difficult age to identify Caspian and Yellow-legged Gull in cases where the latter is atypical in appearance and close to Caspian, on current knowledge no one feature other than the 'long call' can clinch the identification at this age, sadly this bird did not call. The bird was assumed to be a small female. 


Using the criteria laid out in BB in 2010 (Vol. 103, 141-204) here's a very brief analysis with emphasis on the key features:


Structure & bare parts: 
Size similar to small Yellow-legged but slimmer and somewhat narrower winged; 
legs longish and quite thin with a good amount of tibia on show pale greyish flesh coloured; head small and rounded; attenuated rear end and high chested though no significant ventral bulge and no tertial step. These features favour a small female Caspian but some could be shown by a minority of small female Yellow-legged.
Bill slim narrow with a minimal gonydal angle and with the bill length 2.5x + the depth at the gonys. Very strongly indicative of Caspian, colour a little bright than would be expected in typical Caspian though.
Eye colour appeared dark the iris actually being dark grey/brown when close indicative of Caspian. 
Plumage:
Mantle colour within the range of both Caspian and Yellow-legged.
Underwing white - strongly indicative of Caspian. 
Primaries in active moult - inner primaries appear to have been moulted (?) so lacks the venetian blind effect of 2nd winters though there is some suggestion of a contrast between pale grey inner webs and black outer webs, this is only present on some Caspian and is said to be absent on Yellow-legged. 

Even taking an over cautious approach this was a female Caspian Gull rather than a small female Yellow-Legged Gull. In fact it very much has the appearance of the darker mantled round headed eastern barabensis form of Caspian Gull  'Steppe Gull' (e.g. check plate 467 of an adult in Olsen and Larsson)


Poscript: increased numbers of Caspian Gull sightings evident in various locations across the  east of England over the two days following this sighting so clearly there had been an arrival of this species from the east....

Grafham Water 2 July 2012

Wandered around the lagoons and along the dam in rather damp conditions...rather quiet
2 Little Egrets, 9 Yellow-legged Gulls, a single adult Ringed Plover, a Redshank and 3 Green Sandpipers were the best of  it...