Since its looking like this is less of a rare bird subject and more of a what the "f" was that subject, I thought it was time to open up a new thread, for immediate consignment to the unidentified box. It has the advantage that I can edit here and keep the first post up to date with the latest views, links etc. The original thread is >---HERE---<
So, here is the currently collected body of knowledge on the Chinatown Warbler. I'm particularly keen to hear from people who saw the bird. Can you confirm any of the field observations? Disagree with any? Have anything to add? Also keen to hear with field and museum/handling experience to confirm and clarify the usefulness of any of the features described.
The expert view is that this is most likely a Reed Warbler. It seems useful to try and pin down all the features that lead to this bird being thought as being not a Reed Warbler by everyone who saw it. Which are confirmed by the photographic record, which are contradicted etc. It would also be interesting to establish how common some of the apparently anomalous features are in the Reed Warbler population.
I shall keep this first post updated as new information becomes available. And gradually tie in the various photographs that illustrate this.
Features
Behavioural
Tail carriage
• Field Obs: Carried tightly together. Viewed from below the tail was almost invariably seen as two parallel sets of overlapping feathers with a distinct notch between them.
• Photographic evidence This is confirmed in many photographs of this bird. >--HERE--<.
• Species/Genus compatibility Consistent with Hippolais, inconsistent in my experience with Acrocephalus, which tend to hold their tails loosely.
Tail movements
• Field Obs: Tail was flicked open from its tightly closed position, used for balancing, lifted on landing and very occasionally (once in my obseravation) dipped like a Chiffchaff.
• Photographic evidence n/a
• Species compatibility Tail movements inconsistent with previous experience of EOW (though I have heard that e.g. The Cape Clear EOW did not tail dip). Consistent with Sykes' and Booted Warblers. Inconsistent with experience of Reed Warbler in normal habitat. (Need to grill the next arboreal one). This may be more to do with tail carriage than movement.
Gait/carriage/feeding action
• Field Obs: Prone to very long and very fast runs (1-2m) where it looked like a Locustella Warbler. Clambered like a Radde's Warbler when reaching for food. Not seen to hop. Relatively acrobatic, e.g. would go upside down, flycatch etc, again reminiscent of a large Phyllosc. Carriage horizontal (likened to Blyth's Reed Warbler with its tail held flat). Leg length and habit of creeping, contributed to a Tree-pipit like profile. When not feeding it would sit completely still.
• Photographic evidence Scuttling run filmed, aptitude for acrobatics, horizontal stance and high leg action also captured. >--Stance--<
• Species compatibility Inconsistent with my memories of arboreal Reed Warbler, which tended to hop. More inconsistent still with EOW. Sykes'/Booted?
Flight
• Field Obs: Looked wingy and short-tailed (compared to its appearance in trees)
• Photographic evidence N/A
• Species compatibility looked a lot less "clumpy" than EOW and more dashing than Reed Warbler. Need info of Booted/Sykes'
Structure
Tail shape
• Field Obs: In the field this appeared to be rather square, verified when the tail was twitched/fanned.
• Photographic evidence In some photographs the tail appears a little more rounded than it did in the field, perhaps because it is possible to resolve the shorter outer feathers when the tail is tightly closed. In many photographs the field appearance is confirmed. >PICS<
• Species/Genus compatibility The field observation is more consistent with Hippolais than with Acrocephalus, though validity of the field observation slightly questioned by the photographic evidence. There is overlap between EOW and Reed Warbler in this feature.
Length of Under-tail Coverts
• Field Obs: Seemed short and Hippo-like in the field, lacking the "puffy fullness" of typical Reed Warbler
• Photographic evidence Several photographs show longer uts than were apparent in the field, though there is a lack of "bulk". >here<
Tail shape
• Field Obs: In the field this appeared to be rather square, verified when the tail was twitched/fanned.
• Photographic evidence In some photographs the tail appears a little more rounded than it did in the field, perhaps because it is possible to resolve the shorter outer feathers when the tail is tightly closed. In many photographs the field appearance is confirmed. >PICS<
• Species/Genus compatibility Short undertail coverts is frequently cited as a useful feature to separate Hippolais from Acrocephalus. That said there are many photographs of especially EOW, that have very long utcs.
Head shape
• Field Obs: Angular and sloping forehead, peaking behind the eye, when viewed side on. Harder to judge when the bird was higher up
• Photographic evidence Gives a little less angular impression in many of the photographs, perhaps due to viewing angle, or perhaps the field observation was mistaken
• Species compitability Consistent with Reed, EOW and Sykes', inconsistent with Booted.
Tail feather shape
• Field Obs: Appeared rather square ended, though perhaps an effect of the tail carriage. No sign of the typical pointed central TFs of an Acrocephalus (Perhaps missing? Moult sequence needs checking)
• Photographic evidence Feather shape confirmed in the photographs.
• Species compatibility Needs more research, but would appear to be in favour of Hippolais
Leg length
• Field Obs: Seemed very long in the field, perhaps amplified by gait.
• Photographic evidence Field impression confirmed. >pics< showing comparison of leg length and strength, to Reed Warbler. Also using calculated from typical Reed Warbler values for wing tail and bill lengths, from measured tarsus length in Reed and Manchester Warbler. There is a good fit with Reed Warbler and a poor fit with the Manchester warbler in a large number of repeats. Photos can make the legs look shorter tan they are in relity, but NOT longer.
• Species compatibility Needs more research, but appears to be incompatible with Reed and EOW. Compatible with Booted, and perhaps Skyes'
Tertial spacing
• Field Obs: Not easy to judge in the filed, though there was an impression that they were even.
• Photographic evidence As far as can be determined, the tertial spacing are even.
• Species compatibility Sykes' is supposed to have uneven tertial spacings (gap between 2nd and 3rd smaller than 1st and 2nd, though there are plenty of photographs of supposed Sykes' where this is not apparent. More research needed. Compatible with Reed, EOW and Booted
Tertial length
• Field Obs: Not observed in field
• Photographic evidence Seen in all pictures where it is possible to just the length of the tertials, that they are shorter than the secondaries
• Species compatibility Wear may be a factor here (though the tertial tips are still showing strong fringes). Reed often shows tertials which are longer than the secondaries. They are usually shorter in Hippolais. Needs more work to check this out.
Claw length
• Field Obs: Not observed
• Photographic evidence Clearly rather long and curved >here<
• Species compatibility Consistent with Reed Warbler and inconsistent with most EOW, though several photos of long clawed EOW exist. (unless they were misidentified Sykes'. Booted/Sykes' no info, but some online pics show claw lengths consistent with the Chinatown bird.
Tail length
• Field Obs: Gave the impression of being rather short-tailed (also in flight)
• Photographic evidence not possible to be objective in the photographs, but the relatively short tailed character comes over in a high percentage of the photographs
• Species compatibility Seemed perhaps shorter tailed than Reed. Skyes' is supposed to appeared longer tailed compared to EOW.
Primary projection
• Field Obs: Did not seem long in the field estimated as equal to the tip of the 1st tertial to the tip of the 3rd tertial (which would make it 2/3 of tertials if they were of even length.)
• Photographic evidence Very hard to judge from the photographs, but in the few were it is possible to see both the primary tips and the tertials, this looks to be about right.
• Species compitability Projection too long for Booted Warbler, and Sykes, though there are some photographs which show similar length primaries. Ok for Reed and EOW
Wing Length
• Field Obs: Was hard to estimate in the field - recorded as close to base of tail
• Photographic evidence. Varies according to posture, but in side on photographs the wing tips appear to be level or just short of the base of the tail. >here<
• Species compitability Currently looking into it!
Bill shape
• Field Obs: Deep-based with width being maintained to the outer edge of the gape line (Snouty look). Appeared very long but rather thin in the field, verging on spikey at the tip. Seen to be slightly concave-sided from below. In profile rather flat. The bill size was arguably the most striking feature of the bird.
• Photographic evidence Width of bill base, length , and snoutiness confirmed. Photos suggest that the bill was straight-sided or slightly concave in dorsal profile. Its less possible to confirm the impression of a flat lateral profile. >pics<
• Species compatibility The combination of length, width and snoutiness seems less consistent with Reed Warbler but that might just be perception. Booted has a small bill. EOW should have a heavier, less spikey appearance. Good fit with Skyes'.
Wing structure
• Field Obs: Not observed
• Photographic evidence In one analysed photograph, indications of a single emargination (presumed 3rd). >here< In several other photographs, suggestion of more than one emargination 3/4. Possible indication of very long 1st primary, though it could be the unemarginated portion of the 3rd primary somehow outlying the 2nd. A third option would be that the 2nd primary has a tighter radius of curvature than the 3rd. This is seen on the views where the bird's wing is seen from the upper surface - the 2nd primary "slips away" about level with the longest tertial. However, the shaft of the feather inside the bulge is seen to continuous i.e. it is not crossed. >here< Leading edge of wing rather straight. 2nd primary curves under the 3rd in line with the tertials. A futher possibility is that the feature is a secondary. >see here<
• Species compatibility A very long 1st primary would suggest Sykes' Warbler >Manc bird alongside a Sykes'< Absence of an emargination on 4/5/ would rule out Hippolais. Presence of a 4th primary emargination would be rare in Reed Warbler. Unfortuately none of the images is quite clear enough and in a test there are plenty of clear Hippo photographs where 4/5th emarginations are not apparent.
Body Shape
• Field Obs: Appeared chesty and especially "slim-hipped" when viewed from below and from the side. Reminscent of a short-winged Wood Warbler if you ignored the head.
• Photographic evidence Confirmed in >--photographs--<
• Species compatibility Reed tends to look wide at the vent, (Marsh Warbler more so). EOW/Sykes'/Booted?
Rictal Bristles
• Field Obs: Not observed
• Photographic evidence Seen to be strong but short and straight (3). No subsidiary bristles seen
• Species compatibility Reed usually have long curved bristles and plenty of subsidiary bristles. Its possible that this bird was growing bristles and the smaller ones might not have been resolved. Hippolais have short straight ones. Needs research.
Plumage/bare part colours
Outer tail feathers
• Field Obs: Outer web of outer tail feather close to white especially distal 1/3rd, rest of feather pale. Confirmed though prolonged observation and visible in shadow and reflection as well as transmission. Other feathers fairly uniform (no pale tips apparent). Not obvious in flight, though it was hard to get bins on the bird in flight. Could be hard to see unless the tail was flicked.
• Photographic evidence Consistent with field observation.
• Species/Genus compatibility Consistent with EOW, Sykes' and Booted Warblers. Inconsistent with Reed Warbler which is more likely to have tips whitish. Wear and bleaching unlikely to produce such clear effect. Partial leucisism may explain feature.
Tertial pattern
• Field Obs: Conspicuous pale fringes. Tertial centres did not stand out from the rest of the birds upperparts. Fringes worn on the outside edge but [unusually] abrubt and sharp on the inside edges. Tertial fringes obvious in all observations where the tertials were visible, regardless of lighting conditions, viewing angles etc.
• Photographic evidence Field observation confirmed. In photographs where the tertial centres appear dark, they still appear to be the same colour as the inner webs of the secondaries etc. Where the tertial fringes are resolved the proximal edge is abrupt, without any hint of modulation. The distal edge is heavily abraded. >PICS<
• Species compatibility Wear and fading are extremely unlikely to create sharp inner edges to the tertial fringes. In fresh plumage Reed Warbler may have quite conspicuous fringes. These tend to be lost in wear and as far as I can tell, rarely have the sharp internal demarcation. Here is one that does >post< The lack of dark centres would seem to count against Booted Warbler. The tertial pattern is consistent with EOW and Sykes' Warbler.
Alula
• Field Obs: Appeared obviously darker than the rest of the bird, suggestions of a narrow pale fringe to the feather
• Photographic evidence Confirmed in photographs.
• Species compatibility This is compatible with Reed, Booted and EOW. Sykes' is supposed to have a less contrasting alula, though this is not always apparent in photographs (which may of course not be attributed correctly). Needs research.
Leg colour
• Field Obs: Could appear suprisingly pale (pinkish horn) in the field or dark horn depending on viewing angle. My notes compare to Whitethroat.
• Photographic evidence Sides and rear of tarsus appear pale pink in many views. The dark front is less evident. The feet are concolorous with tarsus, with as far as can be told, no obvious difference between to soles and the tops >here<
• Species compatibility Adult Reed Warbler can have flesh coloured legs, but not usually this pale. Inconsistent with the grey legs of EOW. Booted/Sykes'? Booted should have contrastingly darker foot.
Claw colour
• Field Obs: Not noted
• Photographic evidence Seen to be rather pale in many photographs, expecially those when not back lit, or when there is a branch or similar to provide a comparison, suggesting that this is a real feature. In some photos the claws, especially the upperside of the hind claw can be seen to be much paler than the [already pale] toes. >pics<
• Species compatibility Reed Wabler should have darkish claws. Hippolais? but claws flesh coloured or white in young birds, no data for adults.
General colouration of upperparts
• Field Obs: Looked pale, and depending on the light conditions could take on a grey/brown (in open sunlight) or an olive/grey complexion (under leaves). My notes say like pale fuscus Reed or Booted. In all conditions where it was possible to judge, the upperparts appeared uniform apart from the alula and tertial fringes.
• Photographic evidence Varies hugely in the photographs, from greenish, to rusty. presumably reflecting both the differences obvious to the human eye and variations in exposure, white balance etc. There is evidence of heavy wear on some of the upperpart feathers (at least lower back and crown) suggesting that there is a risk that feather bases as well as tips are contributing to the colour.
• Species compatibility Too pale and lacking in warm tones to be a normal Reed Warbler, though if all the rufous tips are warn off perhaps and the whole bird is bleached, perhaps it could fit. Not grey enough for a classic EOW, though the wear and feather base argument could apply here too. What colour are the bases of Olly contour feathers? Good match for Booted Warbler. Sykes'?
General colour of the underparts
• Field Obs: In sunlight the underparts were surprisingly warm, especially on the upper breast and the rear flanks. This was warm buff perhaps even verging on rusty. The undertail, belly centre and throat appeared much whiter. Under the trees the bird took on a more silvery appearance.
• Photographic evidence Again this varies. A couple of photos exaggerate the warmth and the extent of the "not white" parts of the the underparts. Notably, however, the shots that capture the tone more accurately, still show a hint of warmth on the rear flanks. >here<
• Species compatibility Reed Warbler should be rather warmer underneath, though wear could be used as an excuse. Good match for EOW and Booted Warbler. Sykes' supposed to be silky white below.
Head pattern
• Field Obs: Short but rather prominent whitish super that finshed just behind the eye, suggesting of bridging. no dark upper margin visible in field, but may have contributed to prominence of super. Lores pale, ear coverts suprisingly pale. No eye stripe. No eye rings apparent.
• Photographic evidence Confirms field observation. In some angles there appears to be a slight dark loral line, in most the lores are clearly. (shadow of the gape line perhaps. The super, ear coverts and lores appear concolourous and connected in many photos. In some photographs there is just a suggestion of a dark upper border to the super, but in most there is no indication
• Species compatibility The pale ear coverts and lores are not great for Reed Warbler.
Bill colour
• Field Obs: Upper mandible dark horn, lower mandible pale, from straw to slightly on the orange side of pink depending on light. Suggestions of a dark tip to the lower mandible dispelled by observers who saw the upper mandigle hook over the end of the lower one.
• Photographic evidence Confirmed field observations.
• Species compatibility Booted Warbler should have a dark tip to the lower mandible, fits with Reed, EOW, Sykes'
Eye colour
• Field Obs: Appeared uniformly dark in the field
• Photographic evidence In full sunlight the iris appears cold grey in some photos, in others it seems to be dark. >here<
• Species compatibility Reed Warbler should have olive green or rich brown iris, Hippolais supposed to have dark iris, though BWP lists grey/brown as the commonest colour for EOW.
Objections!
These are the anomalies associated with the different candidate species, listed roughly in order of importance (a combination of how certain they are observed and how incompatible they are)
Reed
Tail carriage
Wing Length
Leg length
White outer tail feathers
[hind]claw colour
Body shape
Carriage/gait/feeding action
Colour of upperparts
Head Pattern
Tertial length
Tertial pattern
Tail feather shape
Flight
Leg colour
Colour of underparts
Tail length
Other wing structure
Rictal bristles
EOW
Tail movements
Leg length
Bill shape
Carriage/gait/feeding action
Claw length
Flight
Leg colour
Colour of upperparts
Length of under tail coverts
Other wing structure
Booted
Head Shape
Primary projection
Tertial pattern
Leg/foot colour
Length of under tail coverts
Bill colour
Bill shape
Other wing structure
Sykes'
Tertial spacing
Alula
Colour of underparts
Tail length
Primary projection
Length of under tail coverts
Other wing structure
photographic credits: Steve Williams, Chris Galvin, Adrian Dancy, Steve Young, Rob Smallwood, Pete Rogers.
So, here is the currently collected body of knowledge on the Chinatown Warbler. I'm particularly keen to hear from people who saw the bird. Can you confirm any of the field observations? Disagree with any? Have anything to add? Also keen to hear with field and museum/handling experience to confirm and clarify the usefulness of any of the features described.
The expert view is that this is most likely a Reed Warbler. It seems useful to try and pin down all the features that lead to this bird being thought as being not a Reed Warbler by everyone who saw it. Which are confirmed by the photographic record, which are contradicted etc. It would also be interesting to establish how common some of the apparently anomalous features are in the Reed Warbler population.
I shall keep this first post updated as new information becomes available. And gradually tie in the various photographs that illustrate this.
Features
Behavioural
Tail carriage
• Field Obs: Carried tightly together. Viewed from below the tail was almost invariably seen as two parallel sets of overlapping feathers with a distinct notch between them.
• Photographic evidence This is confirmed in many photographs of this bird. >--HERE--<.
• Species/Genus compatibility Consistent with Hippolais, inconsistent in my experience with Acrocephalus, which tend to hold their tails loosely.
Tail movements
• Field Obs: Tail was flicked open from its tightly closed position, used for balancing, lifted on landing and very occasionally (once in my obseravation) dipped like a Chiffchaff.
• Photographic evidence n/a
• Species compatibility Tail movements inconsistent with previous experience of EOW (though I have heard that e.g. The Cape Clear EOW did not tail dip). Consistent with Sykes' and Booted Warblers. Inconsistent with experience of Reed Warbler in normal habitat. (Need to grill the next arboreal one). This may be more to do with tail carriage than movement.
Gait/carriage/feeding action
• Field Obs: Prone to very long and very fast runs (1-2m) where it looked like a Locustella Warbler. Clambered like a Radde's Warbler when reaching for food. Not seen to hop. Relatively acrobatic, e.g. would go upside down, flycatch etc, again reminiscent of a large Phyllosc. Carriage horizontal (likened to Blyth's Reed Warbler with its tail held flat). Leg length and habit of creeping, contributed to a Tree-pipit like profile. When not feeding it would sit completely still.
• Photographic evidence Scuttling run filmed, aptitude for acrobatics, horizontal stance and high leg action also captured. >--Stance--<
• Species compatibility Inconsistent with my memories of arboreal Reed Warbler, which tended to hop. More inconsistent still with EOW. Sykes'/Booted?
Flight
• Field Obs: Looked wingy and short-tailed (compared to its appearance in trees)
• Photographic evidence N/A
• Species compatibility looked a lot less "clumpy" than EOW and more dashing than Reed Warbler. Need info of Booted/Sykes'
Structure
Tail shape
• Field Obs: In the field this appeared to be rather square, verified when the tail was twitched/fanned.
• Photographic evidence In some photographs the tail appears a little more rounded than it did in the field, perhaps because it is possible to resolve the shorter outer feathers when the tail is tightly closed. In many photographs the field appearance is confirmed. >PICS<
• Species/Genus compatibility The field observation is more consistent with Hippolais than with Acrocephalus, though validity of the field observation slightly questioned by the photographic evidence. There is overlap between EOW and Reed Warbler in this feature.
Length of Under-tail Coverts
• Field Obs: Seemed short and Hippo-like in the field, lacking the "puffy fullness" of typical Reed Warbler
• Photographic evidence Several photographs show longer uts than were apparent in the field, though there is a lack of "bulk". >here<
Tail shape
• Field Obs: In the field this appeared to be rather square, verified when the tail was twitched/fanned.
• Photographic evidence In some photographs the tail appears a little more rounded than it did in the field, perhaps because it is possible to resolve the shorter outer feathers when the tail is tightly closed. In many photographs the field appearance is confirmed. >PICS<
• Species/Genus compatibility Short undertail coverts is frequently cited as a useful feature to separate Hippolais from Acrocephalus. That said there are many photographs of especially EOW, that have very long utcs.
Head shape
• Field Obs: Angular and sloping forehead, peaking behind the eye, when viewed side on. Harder to judge when the bird was higher up
• Photographic evidence Gives a little less angular impression in many of the photographs, perhaps due to viewing angle, or perhaps the field observation was mistaken
• Species compitability Consistent with Reed, EOW and Sykes', inconsistent with Booted.
Tail feather shape
• Field Obs: Appeared rather square ended, though perhaps an effect of the tail carriage. No sign of the typical pointed central TFs of an Acrocephalus (Perhaps missing? Moult sequence needs checking)
• Photographic evidence Feather shape confirmed in the photographs.
• Species compatibility Needs more research, but would appear to be in favour of Hippolais
Leg length
• Field Obs: Seemed very long in the field, perhaps amplified by gait.
• Photographic evidence Field impression confirmed. >pics< showing comparison of leg length and strength, to Reed Warbler. Also using calculated from typical Reed Warbler values for wing tail and bill lengths, from measured tarsus length in Reed and Manchester Warbler. There is a good fit with Reed Warbler and a poor fit with the Manchester warbler in a large number of repeats. Photos can make the legs look shorter tan they are in relity, but NOT longer.
• Species compatibility Needs more research, but appears to be incompatible with Reed and EOW. Compatible with Booted, and perhaps Skyes'
Tertial spacing
• Field Obs: Not easy to judge in the filed, though there was an impression that they were even.
• Photographic evidence As far as can be determined, the tertial spacing are even.
• Species compatibility Sykes' is supposed to have uneven tertial spacings (gap between 2nd and 3rd smaller than 1st and 2nd, though there are plenty of photographs of supposed Sykes' where this is not apparent. More research needed. Compatible with Reed, EOW and Booted
Tertial length
• Field Obs: Not observed in field
• Photographic evidence Seen in all pictures where it is possible to just the length of the tertials, that they are shorter than the secondaries
• Species compatibility Wear may be a factor here (though the tertial tips are still showing strong fringes). Reed often shows tertials which are longer than the secondaries. They are usually shorter in Hippolais. Needs more work to check this out.
Claw length
• Field Obs: Not observed
• Photographic evidence Clearly rather long and curved >here<
• Species compatibility Consistent with Reed Warbler and inconsistent with most EOW, though several photos of long clawed EOW exist. (unless they were misidentified Sykes'. Booted/Sykes' no info, but some online pics show claw lengths consistent with the Chinatown bird.
Tail length
• Field Obs: Gave the impression of being rather short-tailed (also in flight)
• Photographic evidence not possible to be objective in the photographs, but the relatively short tailed character comes over in a high percentage of the photographs
• Species compatibility Seemed perhaps shorter tailed than Reed. Skyes' is supposed to appeared longer tailed compared to EOW.
Primary projection
• Field Obs: Did not seem long in the field estimated as equal to the tip of the 1st tertial to the tip of the 3rd tertial (which would make it 2/3 of tertials if they were of even length.)
• Photographic evidence Very hard to judge from the photographs, but in the few were it is possible to see both the primary tips and the tertials, this looks to be about right.
• Species compitability Projection too long for Booted Warbler, and Sykes, though there are some photographs which show similar length primaries. Ok for Reed and EOW
Wing Length
• Field Obs: Was hard to estimate in the field - recorded as close to base of tail
• Photographic evidence. Varies according to posture, but in side on photographs the wing tips appear to be level or just short of the base of the tail. >here<
• Species compitability Currently looking into it!
Bill shape
• Field Obs: Deep-based with width being maintained to the outer edge of the gape line (Snouty look). Appeared very long but rather thin in the field, verging on spikey at the tip. Seen to be slightly concave-sided from below. In profile rather flat. The bill size was arguably the most striking feature of the bird.
• Photographic evidence Width of bill base, length , and snoutiness confirmed. Photos suggest that the bill was straight-sided or slightly concave in dorsal profile. Its less possible to confirm the impression of a flat lateral profile. >pics<
• Species compatibility The combination of length, width and snoutiness seems less consistent with Reed Warbler but that might just be perception. Booted has a small bill. EOW should have a heavier, less spikey appearance. Good fit with Skyes'.
Wing structure
• Field Obs: Not observed
• Photographic evidence In one analysed photograph, indications of a single emargination (presumed 3rd). >here< In several other photographs, suggestion of more than one emargination 3/4. Possible indication of very long 1st primary, though it could be the unemarginated portion of the 3rd primary somehow outlying the 2nd. A third option would be that the 2nd primary has a tighter radius of curvature than the 3rd. This is seen on the views where the bird's wing is seen from the upper surface - the 2nd primary "slips away" about level with the longest tertial. However, the shaft of the feather inside the bulge is seen to continuous i.e. it is not crossed. >here< Leading edge of wing rather straight. 2nd primary curves under the 3rd in line with the tertials. A futher possibility is that the feature is a secondary. >see here<
• Species compatibility A very long 1st primary would suggest Sykes' Warbler >Manc bird alongside a Sykes'< Absence of an emargination on 4/5/ would rule out Hippolais. Presence of a 4th primary emargination would be rare in Reed Warbler. Unfortuately none of the images is quite clear enough and in a test there are plenty of clear Hippo photographs where 4/5th emarginations are not apparent.
Body Shape
• Field Obs: Appeared chesty and especially "slim-hipped" when viewed from below and from the side. Reminscent of a short-winged Wood Warbler if you ignored the head.
• Photographic evidence Confirmed in >--photographs--<
• Species compatibility Reed tends to look wide at the vent, (Marsh Warbler more so). EOW/Sykes'/Booted?
Rictal Bristles
• Field Obs: Not observed
• Photographic evidence Seen to be strong but short and straight (3). No subsidiary bristles seen
• Species compatibility Reed usually have long curved bristles and plenty of subsidiary bristles. Its possible that this bird was growing bristles and the smaller ones might not have been resolved. Hippolais have short straight ones. Needs research.
Plumage/bare part colours
Outer tail feathers
• Field Obs: Outer web of outer tail feather close to white especially distal 1/3rd, rest of feather pale. Confirmed though prolonged observation and visible in shadow and reflection as well as transmission. Other feathers fairly uniform (no pale tips apparent). Not obvious in flight, though it was hard to get bins on the bird in flight. Could be hard to see unless the tail was flicked.
• Photographic evidence Consistent with field observation.
• Species/Genus compatibility Consistent with EOW, Sykes' and Booted Warblers. Inconsistent with Reed Warbler which is more likely to have tips whitish. Wear and bleaching unlikely to produce such clear effect. Partial leucisism may explain feature.
Tertial pattern
• Field Obs: Conspicuous pale fringes. Tertial centres did not stand out from the rest of the birds upperparts. Fringes worn on the outside edge but [unusually] abrubt and sharp on the inside edges. Tertial fringes obvious in all observations where the tertials were visible, regardless of lighting conditions, viewing angles etc.
• Photographic evidence Field observation confirmed. In photographs where the tertial centres appear dark, they still appear to be the same colour as the inner webs of the secondaries etc. Where the tertial fringes are resolved the proximal edge is abrupt, without any hint of modulation. The distal edge is heavily abraded. >PICS<
• Species compatibility Wear and fading are extremely unlikely to create sharp inner edges to the tertial fringes. In fresh plumage Reed Warbler may have quite conspicuous fringes. These tend to be lost in wear and as far as I can tell, rarely have the sharp internal demarcation. Here is one that does >post< The lack of dark centres would seem to count against Booted Warbler. The tertial pattern is consistent with EOW and Sykes' Warbler.
Alula
• Field Obs: Appeared obviously darker than the rest of the bird, suggestions of a narrow pale fringe to the feather
• Photographic evidence Confirmed in photographs.
• Species compatibility This is compatible with Reed, Booted and EOW. Sykes' is supposed to have a less contrasting alula, though this is not always apparent in photographs (which may of course not be attributed correctly). Needs research.
Leg colour
• Field Obs: Could appear suprisingly pale (pinkish horn) in the field or dark horn depending on viewing angle. My notes compare to Whitethroat.
• Photographic evidence Sides and rear of tarsus appear pale pink in many views. The dark front is less evident. The feet are concolorous with tarsus, with as far as can be told, no obvious difference between to soles and the tops >here<
• Species compatibility Adult Reed Warbler can have flesh coloured legs, but not usually this pale. Inconsistent with the grey legs of EOW. Booted/Sykes'? Booted should have contrastingly darker foot.
Claw colour
• Field Obs: Not noted
• Photographic evidence Seen to be rather pale in many photographs, expecially those when not back lit, or when there is a branch or similar to provide a comparison, suggesting that this is a real feature. In some photos the claws, especially the upperside of the hind claw can be seen to be much paler than the [already pale] toes. >pics<
• Species compatibility Reed Wabler should have darkish claws. Hippolais? but claws flesh coloured or white in young birds, no data for adults.
General colouration of upperparts
• Field Obs: Looked pale, and depending on the light conditions could take on a grey/brown (in open sunlight) or an olive/grey complexion (under leaves). My notes say like pale fuscus Reed or Booted. In all conditions where it was possible to judge, the upperparts appeared uniform apart from the alula and tertial fringes.
• Photographic evidence Varies hugely in the photographs, from greenish, to rusty. presumably reflecting both the differences obvious to the human eye and variations in exposure, white balance etc. There is evidence of heavy wear on some of the upperpart feathers (at least lower back and crown) suggesting that there is a risk that feather bases as well as tips are contributing to the colour.
• Species compatibility Too pale and lacking in warm tones to be a normal Reed Warbler, though if all the rufous tips are warn off perhaps and the whole bird is bleached, perhaps it could fit. Not grey enough for a classic EOW, though the wear and feather base argument could apply here too. What colour are the bases of Olly contour feathers? Good match for Booted Warbler. Sykes'?
General colour of the underparts
• Field Obs: In sunlight the underparts were surprisingly warm, especially on the upper breast and the rear flanks. This was warm buff perhaps even verging on rusty. The undertail, belly centre and throat appeared much whiter. Under the trees the bird took on a more silvery appearance.
• Photographic evidence Again this varies. A couple of photos exaggerate the warmth and the extent of the "not white" parts of the the underparts. Notably, however, the shots that capture the tone more accurately, still show a hint of warmth on the rear flanks. >here<
• Species compatibility Reed Warbler should be rather warmer underneath, though wear could be used as an excuse. Good match for EOW and Booted Warbler. Sykes' supposed to be silky white below.
Head pattern
• Field Obs: Short but rather prominent whitish super that finshed just behind the eye, suggesting of bridging. no dark upper margin visible in field, but may have contributed to prominence of super. Lores pale, ear coverts suprisingly pale. No eye stripe. No eye rings apparent.
• Photographic evidence Confirms field observation. In some angles there appears to be a slight dark loral line, in most the lores are clearly. (shadow of the gape line perhaps. The super, ear coverts and lores appear concolourous and connected in many photos. In some photographs there is just a suggestion of a dark upper border to the super, but in most there is no indication
• Species compatibility The pale ear coverts and lores are not great for Reed Warbler.
Bill colour
• Field Obs: Upper mandible dark horn, lower mandible pale, from straw to slightly on the orange side of pink depending on light. Suggestions of a dark tip to the lower mandible dispelled by observers who saw the upper mandigle hook over the end of the lower one.
• Photographic evidence Confirmed field observations.
• Species compatibility Booted Warbler should have a dark tip to the lower mandible, fits with Reed, EOW, Sykes'
Eye colour
• Field Obs: Appeared uniformly dark in the field
• Photographic evidence In full sunlight the iris appears cold grey in some photos, in others it seems to be dark. >here<
• Species compatibility Reed Warbler should have olive green or rich brown iris, Hippolais supposed to have dark iris, though BWP lists grey/brown as the commonest colour for EOW.
Objections!
These are the anomalies associated with the different candidate species, listed roughly in order of importance (a combination of how certain they are observed and how incompatible they are)
Reed
Tail carriage
Wing Length
Leg length
White outer tail feathers
[hind]claw colour
Body shape
Carriage/gait/feeding action
Colour of upperparts
Head Pattern
Tertial length
Tertial pattern
Tail feather shape
Flight
Leg colour
Colour of underparts
Tail length
Other wing structure
Rictal bristles
EOW
Tail movements
Leg length
Bill shape
Carriage/gait/feeding action
Claw length
Flight
Leg colour
Colour of upperparts
Length of under tail coverts
Other wing structure
Booted
Head Shape
Primary projection
Tertial pattern
Leg/foot colour
Length of under tail coverts
Bill colour
Bill shape
Other wing structure
Sykes'
Tertial spacing
Alula
Colour of underparts
Tail length
Primary projection
Length of under tail coverts
Other wing structure
photographic credits: Steve Williams, Chris Galvin, Adrian Dancy, Steve Young, Rob Smallwood, Pete Rogers.
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