Tuesday, 26 October 2010
Monday, 25 October 2010
Lesser Black-backed Gull (Larus fuscus graellsii), 2cy, 18.10.2010, Børsmose Strand
Putative Western Lesser Black-backed Gull (Larus fuscus graellsii). Judged only on upper part colors we cannot safely dismiss an intergrade between intermedius and graellsii (known as Dutch Intergrade), but it is much paler than a classical Danish breeding intermedius.
Herring Gull (Larus argentatus), 1cy, 22.10.2010, Aarhus Harbor
This is a 1cy Herring Gull with some Yellow-legged Gull features. It deserves a second look due to the pale headed appearance and fairly pale underparts, but argentatus Herring Gull seems as a valid identification. The bird as a whole looks like an elegant female Herring Gull, perhaps from the Baltic region.
Yellow-legged Gull features are: 1) outer greater covert pattern is rather uniformly dark, 2) few second generation coverts are present, 3) darkish outer web on inner primaries, although with a rather large pale 'window' on the outer web, perhaps a little too large for michahellis.
Herring Gull features are: 1) argentatus structure, with head shape perhaps not being angular enough for michahellis, 2) tertials having 'oak leaf' pattern with pale notching together with white edge reaching the greater coverts in some of the tertials, 3) fresh plumage without the normal wear associated with early breeding michahellis, 4) inner primaries with dark subterminal tip on inner and outer web, 5) bill size being in the short and slender end for michahellis, 6) tail pattern with narrow tail band and heavy patterned outer feathers is also more argentatus than michahellis like.
Plumage and proportions looks best for argentatus and the michahellis features are actually seen in some Herring Gulls. Not only are the michahellis features within argentatus variation, but michahellis can show notched tertials with white border reaching greater coverts, extensive pale inner webs on inner primaries and it can even show the dark subterminal primary blobs. Thus there is a lot of variation in most of the characters with some overlap between the two species.
The notched 'oak-leaf' tertials as shown by this bird would be very rare in michahellis seen in Denmark and mostly associated with more eastern Yellow-legged Gull such as around Bucharest as seen here, here, here, here, here, here, here, here and here.
All photos taken by Per G. Henriksen (PGH).
Yellow-legged Gull features are: 1) outer greater covert pattern is rather uniformly dark, 2) few second generation coverts are present, 3) darkish outer web on inner primaries, although with a rather large pale 'window' on the outer web, perhaps a little too large for michahellis.
Herring Gull features are: 1) argentatus structure, with head shape perhaps not being angular enough for michahellis, 2) tertials having 'oak leaf' pattern with pale notching together with white edge reaching the greater coverts in some of the tertials, 3) fresh plumage without the normal wear associated with early breeding michahellis, 4) inner primaries with dark subterminal tip on inner and outer web, 5) bill size being in the short and slender end for michahellis, 6) tail pattern with narrow tail band and heavy patterned outer feathers is also more argentatus than michahellis like.
Plumage and proportions looks best for argentatus and the michahellis features are actually seen in some Herring Gulls. Not only are the michahellis features within argentatus variation, but michahellis can show notched tertials with white border reaching greater coverts, extensive pale inner webs on inner primaries and it can even show the dark subterminal primary blobs. Thus there is a lot of variation in most of the characters with some overlap between the two species.
The notched 'oak-leaf' tertials as shown by this bird would be very rare in michahellis seen in Denmark and mostly associated with more eastern Yellow-legged Gull such as around Bucharest as seen here, here, here, here, here, here, here, here and here.
Saturday, 23 October 2010
Yellow-legged Gull (Larus michahellis), ad, 20.10.2010, Lakolk Strand, Rømø
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| This Yellow-legged Gull has darker upperparts than argentatus in direct comparison. Note hove the black on outer primaries reaches the primary coverts on the folded wing |
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| The fresh primaries have smaller white apical spots than the average argentatus and the tip of p6 extends further beyond the longest tertials than seen on most argentatus adding to the long-winged appearance of this species. P9 and p10 are not yet fully grown thus p8 is the longest primary at present |
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| This Yellow-legged Gull has fine needle-thin winter streaks in head centered especially around the eyes, heavy bill with strong colours and red gonys spot reaching lower edge of upper mandible, red orbital ring and warm yellowish iris, strong head profile, yellow legs, slender and long-winged appearance with elongated body profile. There is a black band crossing p5. P9 and p10 are not fully grown |
Caspian Gull (Larus cachinnans), 4cy+, 20.10.2010, Lakolk Strand, Rømø
This big male-type Caspian Gull has almost complete white summer head and the small darkish eye is situated closer to the flat forehead than in argentatus. The bill is without pronounced gonys angle.
Most likely a 4th winter individual due to black marking in primary coverts, relative large dark spot on upper mandible, and reminisces of classic winter neck-boa this late in season, where adults are typically in complete summer plumage by now.
Most likely a 4th winter individual due to black marking in primary coverts, relative large dark spot on upper mandible, and reminisces of classic winter neck-boa this late in season, where adults are typically in complete summer plumage by now.
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It is standing right behind the one with stretched wings in the left half of the photo
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| Preening in the middle of the photo. Just visible in this photo is the black marking on outer edge of p4, a massive black band on p5 and generally small white apical spots on primaries |
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| It has a good cachinnans jizz with high push up breast, flat belly slightly dropped behind legs and long elongated slim rear. Additionally the upperparts are slightly darker than nearby argentatus |
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| In the stretched wing the grey tongues on the outer primaries are obvious when seen from underneath and the black on primaries creates a classic cachinnans boomerang. The white apical spots are all relative small |
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| Most likely a 4th winter individual due to black marking in primary coverts |
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| Most likely a 4th winter individual due to relative large dark spot on upper mandible and reminisces of classic winter neck-boa this late in season, where adults are typically in complete summer plumage by now |
Caspian Gull (Larus cachinnans), ad, 20.10.2010, Lakolk Strand, Rømø (#1)
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It has a good cachinnans jizz with high push up breast, flat belly slightly dropped behind legs. Additionally the upperparts are slightly darker than on nearby argentatus
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The bill is relative long and without pronounced gonys angle. On the yawning gull the bare part colour in the opened bill was spot on for cachinnans being orangey-yellow at the base of the mandibles where the skin colour in michahellis is typical blood red and light pink in argentatus
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| The longer tibia compared to argentatus is quite distinctive |
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| The small eye is situated more frontal because of the flatter forehead than in argentatus and the eye colour is relative dark with a slight green peppering in the iris – most easily seen when light hits the eye directly - and when seen at some distance it stands out as being dark in contrast to argentatus. There is a thin red orbital ring seen at close range |
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| In the stretched wing the grey tongues on the outer primaries are obvious when seen from underneath and the black on primaries creates a classic cachinnans boomerang. On p5 there is a broad black band and the white apical spots are all relative small |
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It is the one with stretched wings standing in the left half of the photo. The distinctive black feather shafts on the outer primaries in the upperwing are commonly seen in adult cachinnans. There is another 4cy Caspian Gull standing to the right with white summer head, thick neck and strong head profile, possible male
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