Sheffield’s Steppe Shrike update
Posted on December 15, 2010 by Martin Garner
Having reviewed literature, shared notes with local birder Jim Clarke, who also saw the bird well and sought advice, this bird still appears to be a good example of homeyeri Great Grey Shrike: or as the Russians call it Steppe Shrike! At least it has a host of homeyeri characters. I may be there is a yet-to-be-determined line of characters that acceptable vagrant homeyeri must show. Right now, I don’t know which side of such a line, this bird will fall.
For now that doesn’t really matter to me. I have learnt a great deal already about the ‘Great Grey Shrike group’. I plan to have a look at some specimens soon and keep exploring the subject. As so often the enjoyment has been in the discovery, and it’s not over yet!
What follows are photos and text of:
1) a typical 1st winter Great Grey Shrike (nominate excubitor).
2) labelled photos of the Sheffield bird, indicating what can be noted as ‘different’.
3) photos of presumed ‘homeyeri’ to give and idea of appearance which can be compared with the Sheffield bird.
4) some apparent excubitor/ homeyeri intergrades.
5) finally comments from 3 folk with expertise in the subject
1) nominate excubitor Great Grey Shrike
1st winter Great Grey Shrike sp. excubitor. Spurn, East Yorkshire. 20th November 2010. Nigel Genn.
Aged by pink bill base, weak loral pattern, pale tips to greater coverts and worn (brownish) primaries. Check out the short patch of white at primary bases, grey rump and upper tail coverts (same as upperparts). This bird may have some white on the secondary bases, as a section of these are covered by the greater secondary coverts, unlike on the primaries. Open wing or flight views would be needed to check this. excubitor certainly is variable (some have no white at secondary bases, others quite a bit) and we may regularly get some with gene introgression from homeyeri range. Being familiar with the normal features of nominate excubitor is good starting point.
1st winter Great Grey Shrike sp.excubitor. Spurn, East Yorkshire. 20th November 2010. Nigel Genn.
Great shot of the tail! Revealing extensive black typical of excubitor, with black in every tail feather. Some can have all white outermost feather T6 but black in T5 points towards excubitor or intergrade. Gives an idea how very different the tail pattern is on classic’ individuals of excubitor and homeyeri respectively.
2) The Sheffield Bird
Key features of the Sheffield Shrike- noted in the field and visible in photos. No single ID feature but combined seem make strong case on current knowledge for identification as homeyeri, though more research required.
Paler, cleaner less saturated upperparts- also noted by several observers who saw the bird
Large broad white scapulars patch diffusely bleeding into grey. More extensive than normal for excubitor
Odd retained juvenile head pattern including grey lores as per crown and brown forehead (and quiet bright pinky bill base). This combination seems to be normal on some homeyeri and leucopterus specimens, unusual/ exceptional for excubitor. The brown tones on the forehead of the Sheffield bird seems a particularly interesting attribute. Siberian ssp. sibiricus and Northern ssp. borealis/ invictus Grey Shrikes have obvious brown- toned upperparts in juvenile/ 1st winter plumage. Specimens of both homeyeri and more eastern leucopterus seem to show limited brown feathers on the upperparts, particularly the forehead. I don’t know if excubitor in core range show the same kind of brown tones.
Classic homeyeri tail pattern present. An essential character to confirm, without which claims of homeyeri will probably always fall short. T5 appeared to be wholly white. Jim Clarke watched it snag the tail and as far as he could see T5 and T6 looked wholly white- just couldn’t quite get a tiny bit of the inner web near the base as obscured by overlying feather. The first proper black on my photos is on T4 – a bar part way in middle of outer web.
Wing pattern LONG white at primary bases – this can be measured in comparison to length of longest primary covert (from pale tipped alula to start of white). It’s clear that the white on this bird is longer than on many excubitor. Be interesting to see a more accurate length of white at the primary bases can be ascertained in comparison to the long primary covert.
Extensive white on secondaries. On closed wing appearing as broad ‘rectangular’ running about a 40 degree angle to the primary patch and reaching down the wing about 75% as long as the primary patch on the folded wing. In flight shows extensive white on secondaries of similar length to white on primaries. Many apparent intergrades show shorter length of white in secondaries.
Rump whitish– this was tricky especially in changing light conditions Both Jim C. and I agreed on independent views that rump was clearly off white or whitish especially compared with the grey uppers. Confusingly at times the uppertail coverts looked white, other times greyer. Then I realised that white translucent feathers overlying black tail can look misleadingly grey.
Photos not great (better than none!) but labelled to show features. These features were much clearer and carefully recorded through 32 X ‘scope!
Here’s the spread tail – classic homeyeri pattern, confirmed by field views. I know the rump area look greyer here! Can’t explain why, but in careful field views the rump and uppertail coverts were similar tone to underparts- basically whitish- not gleaming but slightly off white, obviously paler than rest of upperparts.
This in-flight shot labelled by Ian Lewington shows his assessment of feather tracts. Somewhat confusingly in some flights poses, shrikes can hold the inner part of the wing semi-closed, thus hiding the true pattern of white, as here. Some of the white in the secondaries is hidden underneath the bunched greater coverts. The upper (labelled) bird is the Sheffield Shrike. The lower bird in similar pose is an apparent intergrade excubitor/ homeyeri from Krakow, S.Poland in November 2009. It differs from the Sheffield bird in having more of ‘step’ between white primary and secondary ‘bars’ and black spot on P5. See full range of shots of the latter bird and how white in wings varies greatly in appearance: http://gneubauer.republika.pl/GreatGreyShrike.html
(with thanks to Grzegorz Neubauer and Ian Lewington)
3) photos of presumed ‘homeyeri’
Some here from Kazakhstan:
Photos below of adult bird taken in NW Romania in September 2009 by Luca Dehelean.
Panov (in press) notes the boundary of the ranges of nominate excubitor and homeyeri at the border of Romania and the Ukraine and a little eastward. Thus birds seen in south and east Poland and Northern Romania are likely to includes ‘good’ homeyeri and ‘obvious’ intergrade types.
Adult Steppe Shrike ssp. homeyeri. Arad, Romania. September 2009. Luca Dehelean. Other may identify as not 100% homeyeri- it may come down to where we draw the line!
The extent of white on the closed wing (here with black greater coverts slightly dishevelled) is very similar to that on the Sheffield bird as it appeared in the field.
same bird as above showing classic homeyeri tail pattern
Same again showing extent of white on open wing. Also note how whiter rump and upper tail coverts appear different in above 2 photos, and not necessarily an easy feature to ‘read’ in the field.
homeyeri (left) compared nominate excubitor (right) Patrick Engstrom, September, Sweden (from Alula magazine).
This is one of Sweden 6 accepted records of homeyeri. Critical features visible in the photo include homeyeri tail pattern, longer section of white at primary bases, and broad rectangular of white at secondary bases. Both the wing and tail patterns are very similar to that of the Sheffield bird. The primary projection also looks a tad longer doesn’t it?
4) Some apparent excubitor/ homeyeri intergrades.
Intergrades and possible good homeyeri from Sweden. All trapped birds appear to be intergrade to me, but one or more of the ‘field photos’ may represent good homeyeri. Unfortunately key features such as tail pattern not ‘nailed’.
and again this bird from Krakow, S. Poland, November 2009:
Below intriguing set of photos of 2 apparently fresh juveniles from NE Poland. These birds taken same time, same area and possibly from same brood? by Lukas Krajewski in June.
Photos above taken in June so it must be a fresh young bird, isn’t it? The grey lores and wing pattern (especially the white trimmed secondaries) are homeyeri characters. However the lack of extensive white in the scapular fringe or rump/ uppertail coverts and the big ‘step’ between white base primaries and secondaries point to an ‘intergrade’. The bird below was photographed- same time, same area, NE Poland, June.
This look like a pretty normal fresh juvenile nominate excubitor. NE Poland, June, Lukas Krajewski.
5) Expert Comment
Evgeniy Panov – author of new book on Shrikes
It seems to me that your bird looks like a typical homeyeri.
So my congratulations with recording a new bird subspecies for UK.
All best wishes, Evgeniy
Lars Svensson (thanks to Alan Dean):
I contacted Lars Svensson and he replied that he has researched the topic of the ‘grey shrike’ complex in some depth, including excubitor, homeyeri and the notional ‘leucopterus’. Many conclusions from these studies will be presented in the passerines volume of forthcoming photographic handbook of palearctic birds, which Lars and Hadoram Shirihai are co-authoring. For clarity, it is better that the full discussion in that publication is consulted rather than attempting an over-concise summary here. Lars has, however, offered the following comment on the photos of the Sheffield bird:
‘I took a look at the photographs. To me this is just about enough characteristic to be labelled homeyeri. Thus not a v. przewalskii [= ‘leucopterus’]. It is clearly a young male. It appears much paler and cleaner grey (bar the crown on images taken in shadow) than is normal for young excubitor. The wing patch shape and size is the wanted one, and on the tail I count two all-white outer tail-feathers and a r4 with dark limited to inner web (?) of inner 2/3. (Sharper images might refute or confirm this interpretation.)’
Thus, with the necessary proviso that his opinion is based upon an assumption that the photos are accurately representative, Lars is supportive of an id of homeyeri.
“It’s a long while since we examined the skins at Tring, we examined them all but only looked closely at exhubitor, homeyeri & pallidirostris. The Sheffield bird appears to show typical wing and tail pattern for homeyeri with additional supporting features. On that basis, it is most certainly not exhubitor (in my opinion) so that just leaves the question of a possible intergrade. Since it shows no intermediate characters there is no reason to support that theory……