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JonB's Tern (1 Viewer)

I'd agree with Caspian, even though there's hardly any black smudge near the bill tip (which Caspian usually has, Royal doesn't), firstly as the site is inland (near Lake Ontario, Canada), which Royal wouldn't be (exclusively marine), and second, by August, Royal is in winter plumage with a mostly white head; also Royal's bill isn't so stout, and more orange-red.

Michael
 
Can a Caspian can appear so pale on the underside of the primaries?. They're normally very black there, perhaps it's a photographic effect making the primaries look so pale as it seems to be a Caspian in other regards (bill size, location etc...).

Dave
 
I have the same concern about Dave, every book I read about seabirds mention that the outer primaries on the underwing on Caspian are black and this one seems not to have a black primaries from below. The same books mention that a distinctive characteristic of Caspian Tern is the dusky-tipped red bill and this one does not have any show of dusk tip.

Alejandro
 
tom mckinney said:
First reaction was Caspian, but God knows about Royal or any of the other ones that all look the bloody same.

Tom.
Click to expand...
C'mon Tom, you can do better than that . . . you know they don't all look the same !!!! :-O


godwit said:
Can a Caspian can appear so pale on the underside of the primaries?. They're normally very black there, perhaps it's a photographic effect making the primaries look so pale as it seems to be a Caspian in other regards (bill size, location etc...).

Dave
Click to expand...
Hi Dave,

I wondered that too - my feeling was, yes, they can on occasion, because this photo proves it (as it is so obviously a Caspian). Unless there's bright reflected light from water below it or something

Michael
 
I'm sure it's just the unusual degree of illumination on the underwing that makes this look so pale - it's definitely a Caspian, a hint of a dark subterminal area is given on the bill. Those species that do have pale undersides to the primaries also show a dark trailing edge which this bird lacks.

Dave
 
Michael Frankis said:
C'mon Tom, you can do better than that . . . you know they don't all look the same !!!! :-O

Michael
Click to expand...

Not me. I can just about do Little and Caspian Terns (!), and everything else is just Sterna sp.

I hear that most terns in Northumberland show mixed characters between Sandwich/Roseate/Lesser Crested. ;) ;)
 
Shirihai, Christie and Harris in birds of Europe and Middle East mention that rarely the black is restricted to just the tips of the prims but this bird looks even more extreme - must be due to the photograph although everything else looks 'normal'

very strange
 
I've seen 100's of Caspians and never seen one with an underwing pattern like this... don't suppose there is a pic of the upper wing too... I guess though unfeasibly pale (they often look like Gannets from below the primaries are so dark) its a better fit than the only other contender (Royal) which should show some contrast between paler primary bases and darker primary tips
 
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Some wisdom from the Helm guide Terns of Europe and North America:

Adult summer Caspians have a complete moult from late July to late September; this bird is just starting, as can be seen on the forehead, but all the remiges will be old. Bill is not a problem, as Michael implied:
Bill coral-red to carmine-red with narrow yellowish tip and with blackish-grey or brown ring just before tip; ring often only hinted at, sometimes lacking, especially during period when feeding young...
​
Wings:
Underwing is white with outer 5-6 primaries blackish-grey, the latter forming a solid dark area on the underside of the hand (sometimes slightly paler on inner part and outermost primaries, very rarely reduced to broad black tips on 5-6 outer primaries).
​
Adult summer Royal also has a white underwing with dark grey tips to outer 5-6 primaries and narrow pale edges; primaries 7-9 have broadest dark tips. Worn outer primaries may have paler grey tips.

Royal's bill is heavy with downcurved upper mandible and prominent gonydeal angle; orange to orange-red, paler and yellower from July. West American population in general has a stronger bill.

Jon's bird does seem to score more points for Caspian than Royal.
 
Hi all,
While I agree that this has to be a Caspian Tern,I too am surprised by the lack of a dark 'wedge' on the under primaries,which is normally so obvious on the species.Might American birds be more likely to be pale here?
Harry
 
Harry Hussey said:
Hi all,
While I agree that this has to be a Caspian Tern,I too am surprised by the lack of a dark 'wedge' on the under primaries,which is normally so obvious on the species.Might American birds be more likely to be pale here?
Harry
Click to expand...


Does not the right wing prove how dark the under primaries can look when not lit by the sun ?
 
Hi Colin,
While taking your point about how dark the underwing looks on the right wing (as well it should,seeing as how that wing is in shadow), I was referring to the dark underprimary 'wedge' shown by Caspian Tern,which is a real plumage feature and would be expected to be apparent on the left wing.
Harry
 
Just to illustrate the point

Three US Caspians showing the classic black underside to primaries
http://www.mbr-pwrc.usgs.gov/id/framlst/photo/h0640pi.jpg
http://www.aves.net/birds-of-ohio/caspian.jpg
http://www.ctbirding.org/images/Caspian Tern_BF.jpg

and Royals, with the contrasting dark primary edge.

http://www.birdinfo.com/RoyalTern2004-02-02-001.jpg
http://wildpic.tripod.com/wild/birds/royaltern_dgl.jpg
http://ontfin.com/Fav/Royal_Tern2.jpg

I know that the dark wedges on eg the upper surface of Sandwich terns become darker as a greyish bloom wears off them, perhaps the same is true on the underside wedges of Caspos!
 
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