Id Help - Mumbai, India - 6 (1 Viewer)

[mihir]

Request id help for these terns photographed near Sasoon Docks in Mumbai on 31st July 2024.

1 & 2)

3 & 4)

 

[Southern Viking]

Common Tern (Eastern Common Tern I presume), and Bridled Tern

 

[Valéry Schollaert]

Common Tern (Eastern Common Tern I presume), and Bridled Tern

What is "Eastern Common Tern" for you ? Sterna hirundo tibetana or Sterna hirundo longipennis ?

 

[Andy Adcock]

Never heard this term?

From this it's longipennis

 

[Southern Viking]

Yeah longipennis is usually what's termed Eastern from a UK point of view.

Not pretending I'd be able to tell the difference from the OP photos though

 

[Andy Adcock]

Yeah longipennis is usually what's termed Eastern from a UK point of view.

Not pretending I'd be able to tell the difference from the OP photos though

The only constant from what I'm aware of longipennis is the all black bill in adulthood.

 

[Southern Viking]

Far as I can tell from ebird, tibetana is more likely in this part of range anyway. I meant eastern as in "one of the eastern forms" in my original comment FWIW, but I can't tell whether nominate hirundo could be found there too.

Probably should have just said "Common Tern" and left it as that

 

[Valéry Schollaert]

Far as I can tell from ebird, tibetana is more likely in this part of range anyway. I meant eastern as in "one of the eastern forms" in my original comment FWIW, but I can't tell whether nominate hirundo could be found there too.

Probably should have just said "Common Tern" and left it as that

Yes, according to e-bird, this is what I checked before asking, the default one there should be S. h. tibetana. I see a long bill though, while S. h. tibetana has a very short bill; the OP bird looks like a (western) nominative Common Term IMO which is possible there too.

 

[Brian J Small]

S. h. tibetana has a very short bill

A slight exaggeration Valery - perhaps 2-3mm on average?

 

[Valéry Schollaert]

A slight exaggeration Valery - perhaps 2-3mm on average?

Well, I checked online and it looks very obvious to me on photos I found. I never searched for geographical variations of Common Tern before and opened my eyes to this here thanks to @Southern Viking . I was recently in India, what a pity...

OP bird looks to me like a regular Common Tern and not like the S. h. tibetana I see online.

 

[Brian J Small]

Well, I checked online and it looks very obvious to me on photos I found.

data from 'Terns of Europe and N America', Olsen and Larsson

hirundo - males 39.8; females 35.7
longipennis - males 35.2; females 33.5
tibetana - males 33.8; females 32.2

'very short' is still an exaggeration to me, but tibetana is indeed notably shorter in averaging 6mm (c 15%) shorter