Friday, 25 February 2022

Return to the Alps - 5th to 13th September 2020

After leaving the Ile de Re we headed across France and back to my brother Mike's house at Morillon in the French Alps.

As a regular but infrequent visitor to the Haute Giffre area of the French Alps it not always easy to establish the distribution of individual species. One species pair I have struggled with are the Marsh and Willow Tits so when one of the pair took to visiting his garden feeders I was keen to see which species it was.

Marsh Tit - nominate race palustris
The lack of pale edges to the secondaries and white cheek fading to brown at the rear plus the long outer tail feather looking equal in length to the central feathers are all features of Marsh Tit. It's not very clear on this photo but the cutting edge of the bill has a pale edge towards its base which is another feature of Marsh Tit. Although I have seen Willow Tit in the valley bottom I come across them more regularly at higher altitude in the coniferous woodlands but can't recall having seen Marsh Tit in this habitat.
Marsh Tit - giving a better view of the pale edged bill and again the brown rear cheek
Willow Tit - race montanus with dark edged bill and pale secondary edges but showing some brown on the rear cheek and shorter outer tail feathers

Of course if you can hear the birds calling or singing that is a big help.

I always visit the Lac de Flerier and was placed to see a pair of juvenile Black Terns which are scarce passage migrants here.


Black Tern - juvenile

On the 11th September I walked up to the Col de la Golese a migration watch point just a few km SW of the more well known Col de Bretolet.

A Golden Eagle circling high overhead was a good start and was briefly joined by a Common Buzzard which made a good size comparison.


Golden Eagle immature with Buzzard (lower photo)

As I approached the col I could see several Griffon Vulture in the distance at the northern end of the Col de Cou, although they were about 3km away they could be readily identified and after some time a group drifted towards me. I counted 22 but I think there were quite a few more as some were landing on the peak. It's the most I've ever recorded in the area.

Griffon Vultures

Stood on the col I could hear Black Grouse calling in the distance as well as at least 2 Black Woodpecker plus several Great Spotted and Green. A few Coal Tit were also crossing the col, I counted 18, along with 4 Crested Tit  and I saw a large group of what appeared to be mainly House Martin flying south which I estimated at 600 birds. On the ground I saw several Northern Wheatear and Black Redstart and at least three Citril Finch. 

The highlight though was a group of European Bee-eater, a species I have not previously recorded in the valley. I counted 15 as they flew rapidly south over the col calling. They were almost impossible to photograph but I managed one shot that is just about identifiable as a bee-eater.

European Bee-eater
Mike told me of several Bearded Vultures that were being seen regularly at the Col de Cenise in the Bargy mountains. I've seen them many times on the other side of the mountains at the Col de Colombiere but the Col de Cenise was a new area for me.

Interestingly this is where the Bearded Vulture that visited the UK in 2020 was born so it had travelled a long way as a youngster and was perhaps now back in this area.

We walked up the col on 12th September with no sign of any vultures. Eventually my brother and his wife, Christine separated from us to try a different area. We had barely been separated for 5 minutes when Pam and I picked up a Bearded Vulture gaining height from below the rock face in the mountains. It was a long way off but was coming a bit closer when an adult appeared very close and crossed the col giving fantastic views. Whilst watching this bird the second bird, an immature also came over us. I couldn't believe our luck. It shows how easily these birds can pass by unnoticed when we met up with my brother again and they had seen nothing.

Bearded Vulture - adult
Bearded Vulture - immature perhaps 3rd calendar year with two ages of flight feathers

Bearded Vulture - the immature rising out of the valley

Bargy Mountains from the Col de Cenise
On our last couple of days I drove up to Samoens 1600 where the star bird was a Spotted Nutcracker a bird which I see on most visits but usually just one or two birds.

Spotted Nutcracker

Wednesday, 16 February 2022

Ile de Re - 27th Sep '21 to 3rd Sept '21

 After all the on/off COVID restrictions in both the UK and Europe Pam and I finally got away to France at the end of August. Following our usual overnight stay at Camping St Louis in Autingues we headed for the Atlantic coast arriving at Eden Villages Camping L'Ocean on the Ile de Re on the 27th.

The Isle de Re is located about mid-way down the French Atlantic coast and is connected to La Rochelle by a spectacular road bridge which cost €16 for a car but there is no toll on leaving the island. Once on the island a bike is the perfect way to get around as there are cycle tracks all over the island.

Black-winged Stilt

The L'Ocean camp site was an ideal base and we spent most of our time exploring the salt pans and marshes west of the camp site but did make a couple of trips to the main town Saint Martin de Re.

Ile de Re: 1 Camp site, 2 Lilleau des Niges Reserve, 3 Phare des Baleines, 4 Tidal mudflats

We recorded 110 species during our week on the island with a good mix of resident and migrant species. All our records are on eBird under Isle de Re. For some reason the subsidiary sites on eBird for Isle de Re don't link to an island total so I entered everything as Ile de Re. 

There are some regular French birders who also put records on eBird so it's fairly easy to get an idea of what occurs where and when.

Salt pans close to Ars en Re

The campsite itself held a variable number of passerines with Firecrests, Pied Flycatchers and up to 3 Melodious Warblers.

Firecrest - male looking rather worn

Melodious Warbler
A couple of Black Redstart frequented a restaurant on the Chemin du Jardin du Boutillon. A small wooded area close to the coastal mud flats at 46.2073 -1.4915 held more migrants with Common Redstarts and several Common Nightingale giving their distinctive, autumnal croaks and whistles. As usual they were a lot easier to hear than see!
Common Nightingale
There was a small passage of birds of prey with Honey Buzzards on 29th (2), 1st (6), and 2nd (2). I also saw a Short-toed Eagle on 1st September which is close to the northern edge of its range in France and must be scarce on the Ile de Re and an Osprey flying south over the sea on the same day. Single Hobby were seen most days with three on the 1st.

Honey Buzzard - adult male top and juv 
Osprey -juv

Eurasian Hobby - adult

Marsh Harrier - male with Belgian wing tags
Living inland I was interested to see what gulls were present on the island. Around the salt pans there were individual Yellow-legged Gulls with a maximum of 10 counted. I also encountered several groups of Lesser Black-backed Gulls of the western race graellsii and up to 40 Herring Gull. Great Black-backed Gulls were seen in single figures and appear to be resident birds from the reports on colour ringed birds I saw. I counted 94 Mediterranean Gulls which favoured a small pool by the harbour at Ars en Re. Several birds were colour ringed and whilst some had been ringed in France two were from Hungary.
Yellow-legged Gull with darvic ring
Mediterranean Gull with French colour ring
The various salt pans held a few waders, particularly at high tide but there were many hundreds more out on the mud flats which must be an important feeding area for migrant shorebirds. 
I counted over 800 Black-tailed Godwits from a photo when they were disturbed over the mud flats but I only saw two Bar-tailed Godwits.
Black-tailed Godwits
There were many hundreds of Ringed Plover but I was unable to find any Kentish Plover which are here in small numbers. Amongst the Dunlin I found a couple of Little Stint and Greenshank were seen or heard every day.
I was pleased to see migrating Turtle Doves most days but three was my best day count. News this year that France has now banned the hunting of Turtle Doves is very welcome and gives some hope for the species future.
Turtle Dove
On 31st August I noted 47 Spoonbill on the mud flats in area 4 which increased to 58 the following day. As I was watching a group of 30 the following day they all took flight and flew directly over my head which was quite a spectacle. From photos it looked like at least one bird had a metal ring and several birds had coloured Darvic rings (see photo below).
Eurasian Spoonbill

Eurasian Spoonbill - lower bird with coloured leg ring
I only made one trip to the Phare des Baleines lighthouse area which is the best place for sea watching. I managed Gannet and several Sandwich and Common Terns with Sanderling and Turnstone on the beach. There were more Pied Flycatchers in the wooded areas and I had several Serin and calling Cetti's Warblers nearby.
Phare des Baleines
Since returning from the Ile de Re I have found a detailed write up by the Pajot family on the Cloud Birders web site of a year spent on the Ile de Re where they saw as many species as possible travelling on foot or by bike. They managed 250 species with a good selection of rarities so its well worth a look if you are thinking of visiting the island.

Friday, 27 November 2020

A candidate Homeyer's Grey Shrike - Matlock Forest

Local birder Steve Mann found a Great Grey Shrike in Matlock Forest on 21st November, I saw it the following day with Steve and Ken Smith. It spent several hours in a clear fell area perched on top of tall tree stumps and occasionally swooping down on prey items on the ground, presumably beetles and spiders although Steve had seen it take a Meadow Pipit the previous day and impale it on the tip of one of the stumps.

When perched it showed a large white patch at the base of the primaries and a second connecting patch at  the base of the secondaries which is a feature of the SE Russian race of Great Grey Shrike Lanius excubitor homeyeri referred to as Homeyer's Grey Shrike. 

There are no accepted records of Homeyer's Grey Shrike in Britain, although there have been several claims, and a detailed analysis of a bird seen at Blacka Moor, Sheffield in 2012 was posted on the Birding Frontiers website by the late Martin Garner and is still pending in the British Birds submissions files.

Figure 1 Possible Homeyer's Grey Shrike Lanius excubitor homeyeri

Figure 2 Great Grey Shrike Lanius excubitor excubitor- first winter 
Taxonomy

The taxonomic view of the Great Grey Shrike species complex was changed significantly in 2010 following an mtDNA study by Olsson et al and is still not fully resolved and can therefore be rather confusing.

Olsson proposed that the Great Grey Shrike should form a species group with three recognised sub-species; nominate excubitor, homeyeri and leucopteros

Shirihai & Svensson whilst recognising the above group include a number of other races within the overall Great Grey Shrike complex, including pallidirostris the so called Steppe Grey Shrike (a name formerly used for homeyeri!).

Anyway, I will stick with Homeyer's Grey Shrike which is also used by Shirihai & Svensson for Lanius excubitor homeyeri.

Distribution

The Collins Guide gives SE Russia and S Siberia, sometimes wintering on the Black Sea. Shirihai & Svennson quote SE Russia to north slopes of the Caucasus, S Siberia east to W Sayan, N Altai with short or medium range winter movements to S Central Asia.

However there is evidence to suggest that homeyeri is now being recorded regularly in eastern Poland and a paper in Ornis Polonica in 2017 concluded;

'As several Polish records of homeyeri, including observations from the breeding period and a few breeding records suggest, the contact zone between excubitor and homeyeri is likely to include the areas of eastern Poland.'

The same paper identified 29 wintering Great Grey Shrikes in the study area in NE Poland and commented that 2 appeared to be nominate excubitor, 2 were homeyeri whilst most individual showed intermediate phenotypic characters between excubitor and homeyeri or were potentially all homeyeri. The article is in Polish (with an English summary) so it's not clear what the phenotypic characteristics were that were used to separate the two.

There are however lots of photos of birds identified as homeyeri, both in the hand and photographed in the wild on the Polish bird sightings website Clanga.

Ageing

The adult Great Grey Shrike has a complete post nuptial moult in late summer (Jul - early October) whilst first years have a partial post juvenile moult at the same time which does not include primaries, secondaries, tail feathers or primary coverts and none or few greater coverts and tertials. In adults the bill base and lores become paler and this is most pronounced in females. 

The tertials and primary coverts looked to have a brownish tinge in strong light which indicate that the Matlock bird is probably in its first winter with retained juvenile feathers.

Absence of any barring on the underparts and all dark lores suggest that it may be a male.

Identification

Key features to distinguish homeyeri;

  • Significant white secondary patch, 8-35mm on closed wing
  • Garner states; all white outer tail feather (t6) and all white t5 or with limited black. Two all-white outer tail feathers is typical. Whilst Shirihai & Svennson say; tail on average has more extensive white, varying from t6 white with only small dark portion on inner web reaching dark shaft to all white t5-t6. Excubitor typically has significant black on t6 but some may show all white,
  • Upper tail coverts noticeably paler than mantle, they are generally the same colour in excubitor or slightly paler,
  • Scapulars paler than mantle and pale area more extensive than on excubitor,
  • More white over the eye and ear coverts and extending over the bill as a narrow pale line. The grey of the crown and forehead generally meets the bill on excubitor and there is a variable amount of white over the eye and ear coverts.
  • Paler upper parts, pale grey in homeyeri and ash grey in excubitor but this is very difficult to judge and varies with the lighting.
  • Visible white bases to the outer tail feathers so the central black area forms a diamond shape on the spread tail rather than an arrowhead as in excubitor.

Figure 3 Possible Homeyer's Grey Shrike v Great Grey in flight

Figure 1 gives a side on view of the perched bird and shows the extent of the secondary and primary patches on the closed wing. 

The pale area over the eye and bill and pale scapulars are also visible and both areas appear to fade into the pale grey of the crown and mantle respectively creating diffuse pale areas. The mantle and crown are a paler grey than in excubitor and consequently there is less contrast with the whitish scapulars and supercilium ( as noted by Steve Mann on his write-up of the bird). The perceived colour of the upperparts varies with the light as can be seen from the various photos.

In flight (Figure 3) the extent of the secondary parch is much more evident compared with a typical Great Grey. Note that the pale upper tail coverts and broad pale scapulars are also evident compared to the Great Grey.

Figure 4 Possible Homeyer's Grey Shrike (L) v Great Grey Shrike showing paler rump and diffuse whitish supercilium

Viewed from the rear the pale upper tail coverts are apparent but the scapulars and most of the tertials are hidden under the mantle feathers.

I struggled to photograph the spread tail but saw the bird for a second time on 24th November and managed a photo of the partially spread tail Figure 5 and a further photo Figure 6a on the 12th December. Figure 6b was taken on 7th March 2021.

Figure 5 Possible Homeyer's Grey Shrike showing partially spread tail
The outer tail feather (t6) is clearly all white. The next feather in, t5, has a small area of black on the inner web extending to the feather shaft Figure 6a &6b. As noted above some black on t5 wouldn't preclude the identification as homeyeri but this may be too much.
Figure 6a Flight shot giving a better view of the outer tail feathers 
 
Figure 6b Flight shot with inset enlarged t5 with estimated extent of black

Referring back to the flight photo of Great Grey Shrike in Figure 3 where the tail is spread you can see that the black extends right across the base of the tail. Whilst the Matlock Forest bird in Figure 6a & 6b shows a white base to all but the central tail feathers, the outer feathers t5 and t4 showing the most against the all white t6. Comparing t5 to examples of excubitor the black is further down the feather, confirming the observation that there is a larger extent of white below the dark area at the base of the tail. The white at the base of t5 and t4 is visible beyond the upper tail coverts on the spread tail creating the almost diamond shaped black centre to the tail.
Figure 7 Possible Homeyer's Grey Shrike in flight

Figure 7 of the bird in flight gives another limited view of the underside of the tail and the upper photo shows the pattern of white in the secondaries also from the underside.

The extensive white tips to the secondaries appears to be another feature of homeyeri, not mentioned in the main identification guides. In homeyeri the secondaries are pale tipped with broad tips on inner secondaries s5, s6 and s7 (s7, s8 and s9 form the tertials). In first winter excubitor it looks like the white tips are restricted to the tertials whilst adult may show a little more white on the inner secondaries (perhaps increasing with age) but not the broad tips, which sometimes extend up the inner web of the secondaries, shown by homeyeri (Figure 9).

Measurements

Using photos to obtain measurements of live birds is clearly subject to some significant variability but, bearing that in mind, I think they can still provide valuable information.

I used the photo from Figure 1 and took the measurements as marked up below as Figure 8. I used bill depth as the reference measurement as I felt this was probably the most reliable. If the head is not exactly parallel to the observer it should still be the same depth whereas bill length is a more uncertain measurement and varies with the angle of the observer.

Figure 8  Location of measurements referred to in Table 1

Table 1 summarises the measurements and using the average bill depth of homeyeri. All the reference figures are taken from Shirihai & Svensson. 

Table 1 Measurements taken relative to bill depth from Figure 8 using homeyeri bill depth of 9.4mm

The measurements could apply to either subspecies, given the broad ranges reported for both, although BWP gives a narrower range for 30 1st year male birds measured, taken from the Netherlands in winter, with av of 9.2mm for the primary patch and range of 6-13mm. Whilst of the same group only 13 showed any secondary patch with an average of 5.9mm and range of 2-10mm. So the Matlock bird would be outside the range for both primary and secondary patches given for excubitor. Note that figures for the secondary patch in 1st winter females was slightly larger with an average of 7.6mm and range of 2-16mm although it was entirely absent in 50% of the sample of 30 individuals.

Discussion

The Matlock shrike shows all the features attributed to Homeyer's Grey Shrike but may have too much black on t5, the penultimate outer tail feather to be pure homeyeri?

It was still present in Matlock Forest on the 17th December although it can go missing for a week or so. In January 2021 a Great Grey Shrike was seen at Bonsall Moor (7km SW of Matlock Forest), it was seen on 23rd, 24th and 26th January and again on 28th February. I heard about the bird in early March and saw it there on the 7th and was able to confirm that it was the Matlock Forest bird (Figure 6b). I saw it again on 17th March and 3rd April and it was last reported on the 6th April.

The tail and secondaries certainly show a different pattern to the Great Grey Shrikes which were annual in the Matlock area for around 10 years up to 2015 and are the source of my photos in this article.

For any sub-species which intergrades there is a division at some point, with excubitor on one side and homeyeri on the other and it's difficult to say where the line falls and on which side this bird therefore sits but to me it looks closer to homeyeri than excubitor, exhibiting all the known features of homeyeri.

I contacted Tadeusz Stawarczyk of the Polish Rare Birds Committee he commented that over 300 Great Grey Shrike have been trapped and photographed (by Piotr Zablocki) in Poland from which they have developed criteria for the identification of homeyeri. He confirmed the various points noted above and stressed that the tail was the most important feature; t6 and t5 should be white or the latter may have a small amount of black on the inner web. Also he stressed the importance of the pale bases to the tail feathers creating the black diamond noted above.

On the basis of the photos of the Matlock Forest bird, whilst it shows all the features of homeyeri and probably originates from eastern Europe it may have too much black on t5 to be accepted as homeyeri on the Polish Rarities Committee criteria but is the closest documented example to homeyeri recorded in the UK to date.

Figure 9 Homeyer's Grey Shrike trapped in Poland © Piotr Zablocki

Figure 9 is taken from the Clanga website and this bird, identified has Homeyer's Grey Shrike, shows similar features to the Matlock bird with a similar amount of white in the primaries and secondaries and pale upper tail coverts. Clearly, you could argue that this may be an intergrade itself but it does show all the homeyeri features. I have read that there should be no step between the white in the primaries and the white in the secondaries but I think only the race from further east leucopterus is likely to show no step. Note that the appearance of a step is affected by the extent to which the wing is spread.

Looking further afield Figure 10 is Homeyer's Grey Shrike photographed in southern Kazakhstan and whilst this bird looks a little paler on the scapular's and paler over the eye the amount of white in the primaries and secondaries looks very similar to the Matlock bird and it seems unlikely that this could be an intergrade.

Figure 10 Homeyer's Grey Shrike Shardara Kazakhstan © Aska Isabekov

Interestingly, a local friend, Ken Smith, photographed a similar shrike on Beeley Moor in 2012 (Figure 11) which also looks to have some homeyeri features but the penultimate outer tail feather, t5, looks to have more black than the Matlock bird.

Figure 11 Great Grey Shrike possibly homeyeri Beeley Moor Nov 2012 © Ken Smith
It seems strange that no examples of Homeyer's Grey Shrike have been caught at the Bird Observatories on the east coast such as Fair Isle, Isle of May or Spurn.
 
Summary

A shrike was present in the Matlock area from 21st November 2020 - 20th March 2021, at least, which shows features of the SE Russian race homeyeri, Homeyer's Grey Shrike. 

In fact the Matlock bird conforms with the descriptions in Shirihai & Svensson, Garner and BWP in all key characteristics visible without trapping the bird. The acceptable presence of some black on t5 is noted in the their descriptions but not quantified. So on that basis the bird is homeyeri

But, the work done in Poland in recent years has gone further to quantify the acceptable amount of black on t5 in pure homeyeri which, if present, should not reach the feather shaft (Figure 9).

On that basis the Matlock bird does not appear to be pure homeyeri and may have some excubitor genes and it perhaps reasonable to speculate that this bird may originate from the contact zone in eastern Poland referred to in the Ornis Polonica article.

Although there are no accepted records of Homeyer's Grey Shrike in Britain there have been several similar birds in the UK and there are other records in Western Europe which have been accepted by their respective records committees.

It is surely only a matter of time before a pure homeyeri reaches the UK and hopefully this blog post will assist in its identification.

Acknowledgements

Firstly, thanks to Steve Mann for initially finding the bird and corresponding on its identity and also to Tadeusz Stawarczyk for his comments on the bird and for providing details of the work done on homeyeri in Poland.

References

1. Shirihai & Svensson 2018 Handbook of Western Palearctic Birds

2. Garner M 2015 Birding Frontiers Challenge Series - Winter 2014

3. Olssen et al 2010 The Lanius excubitor (Aves, Passeriformes) conundrum—Taxonomic dilemma when molecular and non-molecular data tell different stories

4. Zimowanie podgatunków srokosza Lanius excubitor ssp. w północno-wschodniej Polsce Ornis Polonica 2017, 58: 283–305

5. Handbook of the Birds of Europe the Middle East and North Africa (BWP) Vol 7 Cramp & Perrins 1993



Monday, 26 October 2020

Notes on the identification of a Brown Shrike - Johnny Brown's Common, North Elmsall

A shrike found at Johnny Brown's Common was provisionally identified as Brown (Lanius cristata) on the morning of 18th October but as photographs started to circulate the bird was reported as a possible Turkestan Shrike (also called Red-tailed Shrike, Lanius phoenicuroides ). As more birders saw the bird the 'headline' identity returned to Brown Shrike but still referred to the possibility of it being Red-tailed. 

The bird remained in the same area until the 22nd October and it is thought that agricultural work in the fields next to its preferred area on the 23rd may have displaced it. 

I had good views of the bird on 20th October in both direct sunshine and light cloud and took the photos referred to below with other photos provided by Tom Tams and Pete Garrity as noted below.

Old World shrikes have a complicated taxonomy which is not yet fully resolved but in relation to this bird there were two similar looking species to consider; Brown Shrike Lanius cristata cristata and Turkestan Shrike Lanius phoenicuroides phoenicuroides.

Figure 1 Brown Shrike Johnny Brown's Common


Age and moult

The bird was in good condition with a complete set of primaries, two tertials had been replaced on the birds right which were black centred and white edged and it looked to me that the shortest tertials were both missing, possibly just growing and the middle tertial was missing on the left wing. There were several feathers missing in the tail. 

The post-breeding moult in Brown Shrike is complex starting on the breeding grounds often involving the inner 2 or 3 primaries several tertials and tail feathers. Moult is then suspended and finished on stop overs or on wintering grounds in Oct-Nov (Dec). In Turkestan Shrike the post breeding moult is completed on the breeding grounds in Jul-Sept involving head, body, tertials and several tail feathers (Shirihai & Svensson). 

The fact that the bird was in moult is consistent with the identification as Brown Shrike.

The jet black mask, including the lores, and absence of any barring on the sides of the breast, flanks or mantle indicate that the bird is an adult male.

General appearance

Assessing the size and structure of a lone bird is notoriously difficult but to me the bird looked larger and stouter billed than Red-backed Shrike with a size and shape more akin to a long-tailed Woodchat Shrike. The tail looked narrow as well as long but as noted above several tail feathers were missing.

The underparts were off white with a yellowish tinge to the throat, flanks and undertail coverts. 

The upperparts were earth brown on the mantle and nape with a warm brown crown fading to paler buff above the bill. There was no sign of any white at the base of the primaries on the closed wing but some white was visible in flight on the spread wing.

The rump and uppertail coverts were a warm brown similar to the crown whilst the tail was more earth brown like the mantle. The tail lacked any sign of white bases in any of the feathers.

On the head a black eyestripe extended broadly from the ear coverts to the eye and narrowed in front of the eye to the bill base. A whitish supercilium extended from the bill, joining narrowly above the bill, over the eye where it broadened slightly ending short of the black eyestripe. The bill was extensively blue-grey with dark tip to the lower mandible and dark culmen and more extensive dark tip to the upper mandible.

The eye, legs and feet were black.

Identification

Adult male Turkestan Shrike has a striking white throat and supercilium with underparts that are either whitish or tinged pale orangey/pink. The eyestripe is broad and the black tends not to narrow on the lores creating a more even mask with the black often narrowly extending over the bill. 

Figure 2 Adult male Turkestan Shrike (left) © Steve Young/Birdwatch from Worfolk 2000¹ in a similar pose to the Brown Shrike (right)
The bill looks less bulbous compared to Brown Shrike and is usually black in adult males but can be pale based. 
The head features all support identification of the shrike as Brown. 

Underparts

The off white base colouration with yellowish tinges to the upper breast, flanks, undertail and underwing coverts are indicative of Brown Shrike, Turkestan Shrike should be whiter with pinkish or orangey tones. 
The colouration has doubtless faded when compared with Spring male Brown Shrike but supports the identification.
Figure 3 Underpart and underwing colouration

Upperparts

In adult male Turkestan Shrike the uppertail coverts and tail tend to be the same rufous colour and contrast with the browner mantle. In adult male Brown Shrike the mantle and tail are a similar brown with rusty uppertail coverts as was the case with the shrike at Johnny Brown's Common Figure 4. 

Figure 4 view of the upperparts

Primaries

Primary projection is similar for both species, some photographs and comments on the Brown Shrike indicated that the primary projection was too long. The bird had a habitat of lowering its primaries so that they sat well below the tertials thus exposing more primary tips extending from the base of the secondaries. There were indications of moult in the tertials, as noted above and it seems likely that these feathers were still growing. 

When the primaries were held below the secondaries the primary extension did not look particularly long, exposing 4 to 5 primary tips which is typical for Brown, Figure 5. A longer primary extension with more exposed primary tips could have been indicative of hybridisation.

Figure 5 Brown Shrike primary projection (left ©Tom Tams and right © Pete Garrity) Note the right hand image has been flipped to facilitate the comparison

Both Brown Shrike and Turkestan Shrike show emargination on p3-5 but this was not visible in the field or on photos.
Note also the effect of light on the plumage tones in Figure 5 the left hand image in sunshine whilst that on the right is in overcast conditions.

Brown Shrike has a shorter second primary than Turkestan. According to Shirihai & Svensson(2); p2 falls short of the wing tip by 7-13mm and on the closed wing falls between the 6th and 7th primary in 44% of birds measured, is equal to the 6th primary in 29% of birds measured , falls between the 5th and 6th primary in 20% of birds measured or is equal to the 7th primary in 7% of birds measured. 

In Turkestan Shrike p2 falls short of the wing tip by 4.5-10 mm and on the closed wing falls between the 5th and 6th primaries on 58% of birds measured, equals the 6th primary in 26% of birds measured or falls between the 6th and 7th primary in 16% of birds measured.
Figure 6 Comparison of wing formula

Clearly, the assessment of these features are intended for trapped birds. The second primary is hidden below primaries p3 and p4 which form the wing tip when the bird is at rest. I have been unable to locate any photographs which show p2 on a sitting bird but see the measurements made below on the bird in flight. 

Tail

As mentioned above several tail feathers were missing on the birds righthand side. If you look closely at Figure 3 and and the left hand image in Figure 5 a growing feather is visible at the base of the tail on the right hand side.

Figure 7 Spread tail © Pete Garrity

Looking at Figure 7 nine tail feathers are visible including the short, growing t6 on the birds right as mentioned above. It looks like the outer 4 feathers on the birds left are full grown without any gaps. So the missing feathers look like t2 on both sides plus t3 on the right.

Brown Shrike has a very graduated tail with the outer tail feather (t6) only 70% to 80% of the central (longest) feathers. On Turkestan Shrike the outer feathers are 80% to 90% of the longest feather.

In Figures 7,9 and 10 the short outer tail feather, t6 on the birds left is clearly visible and is perhaps 70% to 75% of the length of the central tail feathers thus supporting identification as Brown Shrike.

In March 2015 a shrike was found in Mendocino County, California, the Mendocino Shrike. It was present for 8 weeks and was subject to a detailed analysis including 100 of photographs in order to establish its identity. They took a number of measurements from photographs taken in the field and compared them with data obtained from museum specimens Figure 8 (Pyle et al 2015 (3)).
Figure 8 Adapted from Pyle et al 2015 see caption to Figure 9 for definitions

I've adapted Table 1b from Pyle et al and renumbered the primaries with number 1 as the small outer primary in accordance with European practice. I didn't include their actual measurements as it is the ratio which is important. Clearly the tail measurements are restricted to the feathers on the birds left side as outer feathers are missing on the right.
Figure 9 Showing measurements from Pyle et al in white, yellow line shows intersection of p2 with p5/p6 © Tom Tams, a= p3-p2 and b= p3 to primary coverts. c= t5-t6 and d= t5 to point of tail feather insertion


Figure 10 Pyle et al measurements using upperside of wing
Results 

Figure 7 ratio a/b = 0.229 c/d = 0.245      Average = 0.237
Figure 8 ratio a/b = 0.244 c/d = 0.233      Average = 0.239

Ratio a/b came just within the range for Brown Shrike whilst ration c/d was slightly low for Brown Shrike but way above the range for Turkestan Shrike. Clearly, there are a lot of variables that can affect these figures but look like they could be of assistance in separating this group of shrikes if decent photographs can be obtained and it is not possible to trap the bird.

Summary

I have checked a range of features used to identify Brown Shrike; upper and underpart colouration, moult, head structure and markings and wing and tail shape all of which are consistent with the identification of the bird at Johnny Brown's Common as an adult male Brown Shrike. 
I have also used measurements described in Pyle et al to confirm that structural differences in the primaries and tail are consistent with this identification and can be used to separate Brown from Turkestan Shrike.

I saw no indication of any form of hybridisation and concluded that this was an adult male Brown Shrike of the nominate race cristata

Notes on the photos; the photos which are not attributed to other photographers have had no alterations or enhancement made to the colours 

Acknowledgements
Thanks to the finders of the bird at Johnny Brown's Common for the chance to study this bird. Thanks to Tom Tams and Pete Garrity for use of their photos and I recommend Pete's video, available on Youtube via this link if you are interested in this bird.
I'm happy to receive any feedback or comments on this blog. via Twitter or via email to andysbutler@aol.com.

References

1. Worfolk, T. 2000. Identification of Red-backed, Isabelline, and Brown Shrikes. Dutch Birding 22: 323-362.

2. Shirihai & Svensson 2018 Handbook of Western Palearctic Birds

3. Pyle et al 2015 The Mendocino Shrike: Red-backed Shrike (Lanius collurio) x Turkestan Shrike (L.phoenicuroides) hybrid. North American Birds Vol 69: 4-35

4. Birding Frontiers Challenge Series - Autumn 2014

5. Panov E On the nomenclature of so called Isabelline Shrikes Sandgrouse 31 (2009) p163-170

6. Ganpule P 2017 Red-backed, Brown, Isabelline and Red-tailed Shrike in Gujarat Flamingo Vol. XV-3 July - Sep, 2017