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Friday, 1 February 2019

The January Review

Hawfinch courtesy of Bill Lester
As the new year got under way the best scarcity action was concentrated into the early days of January, after which things settled into a more familiar pattern mid-month. This is not often a stand-out time for true notables anywhere and so it proved later in the review period despite cold weather setting in. Much of the interest then surrounded Gulls, but not entirely.

"Whole Lotta Rosy", courtesy of Alex White

My previous round-up alluded to a possible lively start to 2019, and so it seemed when last November's Rose-coloured Starling was re-found and photographed on 2nd in Botley, west Oxford. This was again at a private address where the following day four Oxon birders searching for the scarcity were very kindly invited in by the householder, and so were able to record it on our community's behalf. Understandably their impromptu host's generosity did not extend to then accommodating a full scale twitch. But our undoubted bird of the month must be out there still and hopefully may become viewable more publicly before winter's end.



Rose-coloured Starling - photo courtesy of Ewan Urquhart -
video courtesy of Badger

Two of December's absentees from the county soon followed in the first week of January, to build the new month's momentum. A Great Northern Diver that settled at Beale Park, just across the county border with Berkshire, did the decent thing by swimming at intervals through a cut onto the River Thames and into Oxon water. Thereupon it soon became the month's most photographed bird. But none of the snappers managed to kidnap their subject and transfer it to the more usual location of Farmoor Reservoir.

Great Northern Diver, courtesy of Nick Truby

Instead the latter site played host to a second county scarcity, Iceland Gull that was viewed there a number of times from 3rd, before being photographed at nearby Dix Pit on 14th.

Iceland Gull (2w) at Dix Pit, courtesy of Roger Wyatt 
January was generally a good month for our gullers, with Caspian Gull of various ages being recorded sometimes regularly from five places: Didcot landfill, Dix Pit again, Port Meadow, Farmoor Reservoir and the Lower Windrush Valley (LWV) GPs through to month's end. A Mediterranean Gull was also present at some of those sites, and in the Port Meadow roost a number of times between 16th and 25th.

Caspian Gull (adult) at Dix Pit, courtesy of Roger Wyatt (above)
and a 2w at Port Meadow (below), courtesy of Thomas Miller

Mediterranean Gull (1w) at Port Meadow, courtesy of Thomas Miller

On a different note a Black Redstart was discovered at and around Christ Church, Oxford on 19th. Over the days that followed this rather dapper small passerine proved to be as photogenic as Oxon's previous varsity black red at Lincoln College in February 2017. Elsewhere around the colleges a pair of Peregrine stayed faithful to Magdalen College Tower, while two Ring-necked Parakeet remained in the University Parks.

Black Redstart - photo courtesy of Thomas Miller -
video courtesy of Badger





The Best of the Rest
Our several wintering Great White Egret remained a feature of this log, with records still flowing from Blenheim Park, LWV Pit 60 at Standlake and other sites mostly to the west of Oxford. Another white long-legged item, White Stork was reported from Frilford on 19th then the following day near Harwell, but was presumed to be an escape.

Great White Egret at LWV Pit 60, courtesy of Steve Burch

Where wildfowl were concerned, two Common Scoter visited Farmoor briefly on 8th; and two pairs of Mandarin were noted on the River Thames near Pangbourne on 9th. Elsewhere Goosander, Goldeneye, Shelduck, Pintail and Red-crested Pochard all stood out from the more frequent and numerous wintering duck at sites across the county. The category C home counties Barnacle Goose flock maintained a presence around Oxford, while growing numbers of Egyptian Goose offered sightings in different places.

Goosander on the River Thames, courtesy of John Workman

There were a few early wader records with Green Sandpiper at Ardley (2nd) and Sutton Courtenay GPs (7th), a Ruff at Otmoor from 25th till 28th, and an Oystercatcher at Farmoor on 29th. Woodcock were flushed from various locations through the month including Moreton near Thame, and Boarstall áround where an impressive nine went up on 19th. And all the while swirling Golden Plover and Lapwing flocks remained a feature of the winter rural landscape across our county.

Peregrine at Pit 60, courtesy of Andy Last

Less frequent raptors were represented by Peregrine at LWV Pit 60 (13th), Lollingdon Hill (18th), the Downs, Otmoor and elsewhere; while Merlin records came from Otmoor again from 6th, Port Meadow a patch tick on 12th and Yelford also on 12th. RSPB Otmoor's male Hen Harrier continued to put in appearences at intervals, while the resident Marsh Harriers delighted their audience there as always. Reports of Short-eared Owl came from Chipping Norton (8th), Otmoor (23rd) and a number of other sites.

Sparrowhawk - a "Gun Slinger" special - courtesy of Roger Wyatt

Stonechat at Otmoor, courtesy of Jeremy Dexter

To end with some small passerines, Stonechat are worth a mention, with records coming from several locations county-wide. Common Crossbill were sighted at Blenheim Park on the first two days of January, then again on 23rd; while the regular flock remained at Buckland Warren throughout. Wintering Blackcap visited gardens in Standlake and Eynsham towards month's end. And Brambling continued to be found frequently, especially around Chipping Norton in north Oxfordshire.


Ring-necked Parakeet in central Oxford, courtesy of Badger

So now just one more month of winter remains before the first spring migrants begin to arrive. Is there still time for Waxwing, Great Grey Shrike or Smew to feature herein, and might that Rose-coloured Starling reveal itself to more Oxon birders? Keep searching everyone!

Peter Law




DISPLAYING GOSHAWKS - A YORKSHIRE MAN'S EXPERIENCE
by Mick Cunningham




INTRODUCTION


Badger is seemingly still desperate for copy for the blog. So, he asked me to do an article with field sketches, topic my choice. This is it. I moved to Standlake from the Yorkshire Pennines in spring 2017. Oxon birding is definitely different from watching upland birds near my Yorkshire home and migrants at Spurn. With effort, I could see Goshawks annually relatively nearby. But I'm told even some active Oxon birders still need it for the county such is its rarity here.  Before and after the Foot and Mouth outbreak in 2001, friends would monitor breeding Goshawks and some had licenses to ring the young. I've never visited a nest but would alert friends to displaying birds. This resulted in some nests being found, which proved I got the ID right. Sometimes!  Persecution was rife. Goshawks often disappeared soon after starting to display. When Foot and Mouth broke out in February 2001, access to the countryside was restricted and remained so until September, coinciding with Goshawk breeding season. We could not monitor the birds that year. My sites were near/on keepered moors. All these pairs disappeared. It was a decade before a Goshawk was seen in these areas again.





SECRETIVE AND DISTANT


Even when present Goshawks were STILL hard to see. I mostly saw them distantly, performing spring display flights. I think this is how most birders see Goshawks in the UK. So this article reflects my experience, focusing on identification at a distance in spring. I hope it might be useful to those seeking Oxon Goshawks in the next few months.  But I'm happy to be corrected on any of the below. Excuse occasional 'SHOUTY' capitals. The blog doesn't allow formating. I must thank photographer friends for photos: Andy Butler (all photos except displaying Sparrowhawks), Dave Pennington (displaying Sparrowhawks). The photos are copyrighted.


JUVENILE GOSHAWK PLUMAGE


Not discussed as these are easy to ID if plumage is seen well ie accipiter-shaped, brown/ginger brown uppers, with heavy brown/ginger-ish streaks on a pale background below. Sparrowhawks are barred below at all ages.


SKETCHES AND PHOTOS BELOW


I had hoped to use photos of distant Goshawks but the rise of DSLRs means photographers only save close up images.  And no-one seems to photograph displaying Sparrowhawks. Nevertheless, I hope the photos below illustrate some points I make. And I've also reproduced some of my amateurish field sketches which I hope show what the birds look like from afar ie plumage is barely mentioned.



THE BENEFITS OF STUDYING DISPLAYING SPARROWHAWKS


It seems unfashionable to admit to any difficulty separating DISPLAYING Sparrowhawks from Goshawks. But I know some avid raptor watchers who still struggle with this. It certainly challenges me. Both species display at the same time of year. And their displays are (nearly?) identical. I don't know of any display flight- action that differs between them. Moreover, there is always a surfeit of female Sparrowhawks in any population. And it is these, the bigger sex, that display most in that species. So, I find displaying Sparrowhawks are the most Goshawk-like and I think the literature underplays the risk of confusion arising from this. It's easy to be confident at known 'Gos' sites; much less so elsewhere where Sparrowhawks are common.


The basics of display by the two species are well known and involve:

  • Circle soaring over territory: with fluffed out white undertail coverts (tail flagging)
  • Slow (wavering) flying around above a territory with exaggerated, slow wing beats reaching above and below the body line, often with tail flagging
  • Rising high in the air then performing a series of more or less shallow undulations ie flapping upwards then losing height by closing wings, and repeat
  • At its most extreme, the above becomes a 'sky dance', as the bird climbs high then plunges down fast on closed wings until it 'bounces' back up to repeat the move before finally plunging into the trees below at speed.


IDENTIFICATION - THE 'WHOLE SUITE OF CHARACTERS' APPROACH


Thia dreaded phrase means there's no silver bullet feature that separates these species in the field.


What Didn't Work for Me


  • Size: in direct comparison, every Goshawk I've seen was smaller than ... the sky! I rarely saw another species nearby for comparison. Judging size at distance can be hard. Sparrowhawks in slow motion display look much bigger than hunting ones.
  • Prominent undertail-coverts: both show these when displaying. But see below
  • Display flights, too similar (same?)
  • Head pattern: female Sparrowhawk's head pattern is similar enough to Goshawk's for the smaller species to look hooded at a distance
  • Chest bump: some Sparrowhawks show this
  • Head projection: sometimes didn't work


What Did Work (In Combination)


  • Goshawks sit out at top of trees when on territory. Barrel-shaped body (wide-hips) and pallid under plumage is then evident. I've never seen a Sparrowhawk sit out.
  • Overall flight shape: Goshawk - yes it's usually cruciform. Sparrowhawk - yes, it's usually T shaped. BUT there are squatter Goshawks and rangier looking Goshawks (viewing angle? Display postures?)
  • Contours: Goshawks to me are muscular, lumpen looking with bloated outlines. Weightlifters. Sparrowhawks, generally built more like a sprinter - though sometimes with chest bump.
  • 'Rear end' structure difference: USEFULL! Goshawk has wide hips, Sparrowhawk is narrow hipped
  • Tail shape: Goshawk tail USUALLY has rounded/blobby ended tip, but ALWAYS (?) wide at base. On some, the tail looks short. Sparrowhawk tail base narrows at base, tail tip has sharp, clean cut corners, squared off.  Usually looks long.
  • Body shape: Goshawk, deep from chest, through belly to broad hips. Sparrowhawk, shallow bodied, flat belly runs into narrower hips
  • Wing-shape: Goshawk broad but (somehow!) long too, arm longer and broader than hand. Hand tapers.  A bit Honey Buzzard-like. Sparrowhawk (except when displaying) impression is broad: arm and hand of similar proportions; hand doesn't narrow
  • Head projection: Goshawks is longer because thick NECK, runs into longer, triangular 'head'. Sparrowhawk neckless, shorter, rounder head projection (more Kestrel-like)
  • Underparts plumage: with experience, Goshawk has more pallid appearance.

The above will be 'old hat' to many, but will be illustrated in photos and sketches below. There are two speculative separation features from my experience I'd like to explore: the pattern of the underwing for adults, especially the wingtip, and the extent of the 'tail flags' in display.


SPECULATION  #1
DUSKY UNDERWING TIPS ON DISTANT BIRDS: A DIAGNOSTIC DIFFERENCE?



During 2015 - 2016 I occasionally saw dusky tips on the UNDER outer primaries of two ADULT Goshawks which soared at medium distance, a bit like on adult Levant Sparrowhawk. I saw it on a bird I saw abroad too. I never saw it on birds I identified as Sparrowhawks. I considered writing to 'BB' to propose this as a possible ID feature for adult Goshawks. I never did, partly because it wasn't always evident. I wondered if the appearance depends on: lighting; how spread the primaries are; individual variation, or was less evident on less mature adults eg 3cy birds. But, when present, the birds were always Goshawks. Only when I read the latest Forsman Bible (2016), did I realise that the darker bars on the under outer primaries of FULLY adult Goshawks' contrast with the paler inner primaries and secondaries. On Sparrowhawk there is no such contrast. I planned to test this out, but moving to Oxon in 2017 scuppered that. What causes this difference between the species? The basic underparts' plumage of female (and non-orange male)   Sparrowhawks, and all adult Goshawks, is the same. The bodies, underwing-coverts, and underwing flight feathers all show darker bars over a paler ground colour. There are subtle differences. Compared to fully adult Goshawks, Sparrowhawks' bars are both darker and thicker and the paler ground colour less 'white' . The dark bars on the under secondaries and inner primaries of fully adult Goshawks are fine, almost like a 'watermark', and the ground colour of these feathers is also very pale, as it is on the outer primaries.  Hence, the contrast with the much darker bars on the outer-primaries. Field tests are needed but, if seen, dark wingtips could be a good pointer to Goshawk as part of the 'whole suite' approach. AND CONTRAST IS OFTEN MORE MARKED AT DISTANCE.


NB in fact, the Goshawk flight feathers are also paler than the underwing coverts but I find it harder to see this, a lot of the time.


Pallid Underparts: to me, adult Goshawks (especially older adults) often look   PALLID below when compared to Sparrowhawks. This is because, like the flight feathers, the underbody and underwing coverts have finer bars and a paler, whiter, ground colour than Sparrowhawks'.



SPECULATION #2:
DO DISPLAYING GOSHAWKS SHOW SHAVING BRUSHES AND A WRAP-AROUND RUMP?!



Many birders cite prominent white undertail coverts as a pro-Goshawk feature. BOTH species fluff out WHITE undertail coverts in display. And I think the prominence of Sparrowhawks' flags can be enhanced by the sun/your eye, when distance means their duller underparts' markings coalesce to form a contrast against the white flag. Arguably, there's less contrast on the paler bodied adult Goshawk.


Shaving Brushes: I have often seen displaying Goshawks flagging so much that the undertail coverts stick out sideways from the bird, looking like old-fashioned shaving brush bristles. I have never seen this on a Sparrowhawk. Has anyone else? If shaving brushes are present, I will definitely check for pro-Goshawk features.


Wrap-around White Rump: sometimes, the flags extend sideways so much they curl-up to wrap around the rear of the body. This creates an impression of a gap or white rump effect, reminiscent of a ringtail harrier. Again, I've never seen either on displaying Sparrowhawks.



FLIGHT ACTION


I don't usually rely on flight action to separate these accipters during courtship display season. Reasons include the similarity of display flights, when Sparrowhawks often use a slower, heavier flight actions, and the fact that the literature is contradictory on non-displaying flight action. Some authorities state Goshawks' wing flaps are stiffer than Sparrowhawks', others say they are more elastic.  I rarely see Goshawks in non-display flight so cannot confirm that, during level flight, they do NOT lose height when gliding between flaps as the literature says. I have seen Sparrowhawks lose height between flaps though, as per the literature. At best, I find Sparrowhawks' flaps more buzzy and more frantic than the Goshawk's slower, heavier flop that I noted the few times I saw birds in direct flight.


PHOTOS AND SKETCHES WITH CAPTIONS


This section uses photos, sketches and captions to highlight identification features.



Above: Sparrowhawk. Note T shape structure. Broad wings, even though primaries tucked in for hunting flight. Arm and hand about equal lengths. Evenly barred flight feathers,  short kestrel-like head projection. Square ended tail and narrow 'hip' area behind rear edge of wing.




Above: displaying Goshawk. Male of a study pair.  Shape, not too dis-similar to the Sparrowhawk above. I think (but can't be sure) that the most 'Sparrowhawk-shaped' Goshawks are often males, though flight attitude can give this impression. Compare underwing with Sparrowhawk. Note very pale inner wing versus the darker barred outer-primaries.  I wonder if light conditions make these bars burnt out or are they less prominent on some individuals/younger adults? The rear end is evenly wide from hips, through tail to tip. The tail-tip is bevelled..



Above: displaying Sparrowhawk. Note how fluffed undertail coverts subtly alter the undercarriage profile, making it deeper at the rear 'hip'' end, and giving the illusion of a short-ish tail. These are Goshawk features. In silhouette, at a distance, this was identified as a Goshawk by birders not as close to it as me and the photographer.





Above: Field sketches of Sparrowhawk cf the notes classic Sparrowhawk shape, like a T square. Though note reference to sometimes looking longer winged. I think the body length relative to head projection and tail length looks shorter on Sparrowhawk than Goshawk but I could be wrong. Hence notes attempting to measure this. Sparrowhawk features are slim 'hips' where tail joins body and the sharply etched contours of the tail, including, sharp corners. In normal postures, the 'arm and hand' of Sparrowhawks' wings look about equally broad and in the usual rather 'panicky fast flapping flight gives the impression of a single mobile unit (Goshawk 'hand' articulates more from arm?).  



Above: field sketches of Sparrowhawks displaying, diving, and in level flight (tails a bit long). In a full slow flap display or a display soar, the wings can look somewhat longer than expected. Whether slowness creates an illusion of length I'm unsure. It does make Sparrowhawks look big though. Even so, the 'body' is still relatively slim, including at the rear, the head projection is still short, and the tail tip square cut. 



Above: displaying Sparrowhawk. Note short head projection and slim profile with shallow chest and belly.



Above: displaying adult Goshawk. The darker wing tip catches the eye, especially on uppermost wing. Try Squinting or hold at arm's length for an idea of how this might look on distant birds as light shines through the water-marked inner wing. Wing shape is reminiscent of Honey Buzzard. Broad arm bulges at the rear and arm looks longer than hand (usually about equal on Sparrowhawk). Hand tapers. Head projection made up of thick neck and long, triangular head. Tail tip on this bird could be seen as square.




Above: Goshawks in profile.   On left hand adult see pale inner wing versus darker wing tip. Even without this, both birds have deep body from chest, through belly to 'hip' area just behind rear edge of wing.   



Field sketches: Goshawks displaying at distance (and a Sparrowhawk soaring). This is a relatively tricky Goshawk. At a cursory glance, not too dissimilar to Sparrowhawk in some attitudes. Other Goshawks have more protruding, cone-shaped 'head projections', even deeper undercarriages than here, and more obviously long wingss. But Goshawk characters are there. Note subtly 'bloated' lines. Shot putter not sprinter. Tail tip rounded. Head projection drawn a bit short and round for many Goshawks, though some can look as drawn. Body from breast,  to belly and hips, deep and wide. Note upper bird's wing-shape  versus Sparrowhawk. As often said, narrower hand can resemble a Peregrine which Sparrowhawks don't (usually). Level flight bird looks like a short-tailed harrier.




Field sketches NOTE MY PUZZLING OVER 'MUZZY' DARK TIP TO THE PRIMARIES. Goshawks in slow display flight, and soaring. I find soaring posture hard to draw accurately. Bird at bottom was seen attacking a woodpigeon. The bottom birds in each set of sketches show Goshawk's crucifrom shape, not T square. Plus Goshawk's 'Norman helmet' head projection. The hunting bird's wings had more curvy contours as noted at the time, presumably as it flexed and flapped in pursuit of the pigeon.


LAST WORDS


Every year, I had to 'relearn' how to ID Goshawks. And there were still some disant/fleeting birds I had to leave as accipiter sp. I'll bet Oxon Goshawks are like Yorkshire ones, only likely to be seen at a distance and mostly whilst displaying. So I hope some of the above is useful. If not, let me know how to ID them because I need Goshawk for Oxon!


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