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 7 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

Siberian Lesser Whitethroat - Spurn 9th - 12th October

During a long weekend at Spurn with friends we came across a Lesser Whitethroat skulking at the base of a hawthorn hedge. Fortunately it remained in the same area over the weekend and I managed to obtain a series of photographs which confirm, as far as can be confirmed without DNA, that the bird was a Siberian Lesser Whitethroat (Sylvia curruca blythi). This race is now regularly recorded on the east coast in autumn and sometimes over-winters in the UK. 

Since an analysis of DNA from the various races of the Lesser Whitethroat was published in 2013¹ which indicated that blythi is not as closely related to curruca as previously thought and could be a candidate for a future split to form a species group with three other subspecies; althaea, halimodendri and margelanica as one species and curruca and minula in the other there has been increasing interest in identifying these birds, both in the hand and in the field.

Figure 1 blythi in profile, note brown mantle and buff flanks

Identification

The general impression was of the nominate race of Lesser Whitethroat (which I'll refer to as curruca and blythi for Siberian Lesser Whitethroat) in terms of size, structure and behaviour as it moved slowly through the bushes generally keeping low down. In brighter light the brown mantle was the most obvious feature and on closer examination the mantle colour continued up the nape fading to grey on the rear crown unlike curruca where there is a distinct division between the grey/brown of the mantle and the grey nape. This feature was most obvious when looking at the bird from the rear or when looking down on it (Figure 2), it was not so obvious when viewing the bird side on as in Figure 1 above. See also Figure 4 sent by Trev Charlton which show nominate curruca with the mantle colour extending on to the nape although it is less obvious as there is less contrast between the mantle and nape base colouration. Figure 4 also shows the colder, greyer tones of curruca compared to blythi. 

The next distinction from curruca was the colour of the underparts. In this bird the throat was off white but the flanks and lower breast were a warm buff separated by an off white lower belly and undertail coverts but the buff flanks looked to meet behind the legs whereas in curruca the whole of the underparts are off white. Slightly darker brown ear coverts and lores gave a masked effect but how strongly this appeared varied with the light and the viewing angle. 

Figure 2 viewed from behind, showing mantle colour extending on to nape

Figure 3 showing rear flanks and undertail

The tertials were dark centered with pale fringes which combined with the mantle colour brought to mind Common Whitethroat. Primary projection is said to be less than in curruca but there is apparently considerable overlap.

Figure 4 Lesser Whitethroat of the nominate race curruca © Trev Charlton October

A consistent distinguishing feature for blythi from curruca is the position of the tip of p2 against the other primaries in the closed wing. In blythi p2 is short and thus falls further away from the wing tip. This is a straight forward measurement for trapped birds but in the field the wing needs to be spread slightly to reveal p2. Fortunately watching this bird on and off over 3 days I did manage a photo with the wing slightly spread.

Figure 5 with wing slightly spread showing approximate position of p2

Clearly, there is quite a bit of room for error here depending both on the angle at which the bird is viewed and the extent the wing is spread as well as any damage to the tip of p2.

Table 1 Position of p2 in relation to tips of other primaries in closed wing. Figures are percentage of each sample (adapted from BWP)

The further p2 is out of alignment with the remaining primaries the shorter it will appear. Also the angle at which the line is drawn will also have an effect, I've tried to draw the line perpendicular to the primary shafts. Having said all that I think p2 falls around p6 which excludes curruca where p2 falls between p4 and p5 or at p5 in the majority of examples.

If you are not able to obtain DNA the final evidence required is the pattern of white on the outer tail feathers. 

Figure 6 in flight showing spread upper tail

I was unable to see any evidence of a moult limit (mix of juvenile and post juvenile feathers) in the greater coverts which would identify the bird as 1st calendar year but I think the pointed tail feathers are juvenile thus ageing the bird as 1st calendar year. The age is important as there is considerable variation reported between 1cy and adult birds. In its first year the race halimodendri has an all white outer tail feather (t6) so on that basis we can confirm that this bird is blythi. The nominate race curruca can have a similar outer tail pattern to blythi in its first year and both races may show white tips to the neighbouring feathers (t5 and even t4 and t3 in curruca).

I was interested to see if the pattern of the outer tail feather could be seen from the underside of the tail. It looks less distinct but the pattern can be discerned (Figure 7).

Figure 7 Pattern of the underside of t6 from below, note also off white belly

Bare Parts

The iris was brown, similar in colour to the mantle. The bill was dark with a bluish base to the lower mandible extending just over half its length. There was some reddish discolouration around the bill base from the blackberries it was occasionally seen feeding on. The legs and feet were black with paler bluish grey soles.

Call

It was heard to give a tacking call several times which sounded like curruca. No other calls were heard.

Behaviour

Over a four day period the bird was seen frequently in a hawthorn hedge and two areas of bramble extending to about 150m. Most of the time it was within 1m of the ground but occasionally climbed the hawthorns to over 2m. It was very active creeping through the low bushes and appeared to stick to one direction of travel making it possible to predict where it would appear when lost to view. Several times it climbed to the top of the brambles or low hedge and flew 20 - 30m when it would again set off in one direction and repeat the process. The tail was regularly flicked down, much like Common Chiffchaff although it was windy and this may have affected it behaviour in exposed positions. The tail movement emphasised a rather long-tailed appearance. On a couple of occasions it sat on, or close to the top of low scrub to preen.

Photographic Note:

The photos have been cropped and in some instances lightened but there has been no colour adjustments made either by the camera or in post processing.

Acknowledgements

Thanks to Roger Barnes, Mick Cunningham, Paul Doherty, Richard Hart, Vaughan Lister and Johnny McLoughlin and for input whilst watching the bird at various times and comments on its identification. Also Trev Charlton for his comments and use of the photos in Figure 4.

References

1. New insights into the intricate taxonomy and phylogeny of the Sylvia curruca complex Urban Olsson, Paul J.Leader, Geoff J.Carey, Aleem Ahmed Khan, Lars Svensson, PerAlström

2. Handbook of the Birds of Europe the Middle East and North Africa, the Birds of the Western Palearctic Vol VI

3. The Challenge Series - Autumn by Martin Garner

4. Handbook of Western Palearctic Birds Vol 1 Shirihai & Svensson

A few days in Bucharest 29th - 31st January

Incomplete - photos to be added

I'd read several reports of birders visiting Bucharest and was particularly attracted to the reports of Caspian Gulls and woodpeckers, both of which appeared relatively easy to see in the right conditions. For the gulls the' right conditions' were frozen lakes in Herastrau Park, which apparently occurs in most years but unfortunately not this one!
We stayed in the Bucharest Mercure which was about 3km from the park which I did walk several times but we also used Uber which was so easy and cost effective (about £2.50 for a one way trip).
Our first morning in the park was raining but we still managed several Syrian and Middle Spotted plus 2 Lesser Spotted Woodpeckers. 

The trees also held Nuthatch, lots of Tree Sparrows and several Hawfinch. There were a couple of feeders in the park which were a magnet for the Tree Sparrows and the numerous feral pigeons.
As mentioned the lakes were completely ice free and I counted at least 9 Pygmy Cormorant, which I'd probably not have seen if they had been frozen but unfortunately the gulls all appeared to be Yellow-legged. The following day I took some bread with me and managed to attract some of the birds a little closer and all of which proved to be Yellow-legged Gulls.
Walking back to the hotel I called in a Kiseleff Park which also had Syrian, Middle Spotted and Lesser Spotted Woodpeckers.
In the afternoon I visited Cismigiu Park which was closer to the hotel, it is smaller than Herastrau and the pond in the centre had been drained but I still managed a couple of Syrian Woodpeckers and several Hooded Crow.