Anyone know their terns (1 Viewer)

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doug_newman

Well-known member

• Jun 25, 2006

• #1

Hi All.

I wonder if anyone wants to comment on this picture I took a while back of a Tern at Marievale. I was looking at it and noticed the difference in coloure of the inner vs outter webs of the primaries. I then read in Roberts and only Whiskered Tern has this mentioned in Roberts VII. Does that mean that this is a Whiskered Tern and not a White-winged Tern? (Photographed 600 Km inland at Marievale Bird Sanctuary - South Africa)

http://www.sahotspots.co.za/forum/viewtopic.php?p=2156#2156

Comments would be appreciated.

Cheers.
Doug

 

T

Th_SQ

Well-known member

• Jun 25, 2006

• #2

Whiskered Tern (juv moulting to 1st winter) for me : typical tertials and remaining mantle feathers.

 

Last edited: Jun 27, 2006

johnportsmouth

Member

• Jun 25, 2006

• #3

Hmmm can i throw 2 other terns in the mix though i want to say juvenile if it is either.
Roseate Tern & White Cheeked Tern.

Having checked all my books i am siding on Roseate Tern Juvenile though but i cant be sure sorry.

Hope that helps

 

JANJ

Well-known member

• Jun 25, 2006

• #4

Agree with Th_S,Q Whiskered Tern!

WT:

http://www.homepages.mcb.net/wormwell/juv Whiskered Tern.jpg

http://www.oiseaux.net/oiseaux/charadriiformes/images/guifette.moustac.alfo.3g.jpg

http://www.netfugl.dk/pictures.php?id=showpicture&picture_id=4732

WWT:

http://www.tarsiger.com/images/JANDE/Chlleu.JPG

http://www.birdsireland.com/images/2005/september/wwbt_Swords0309.jpg

http://www.birdtours.co.uk/tripreports/Spain/andalucia10/Andalucia Sept 2005_files/image004.jpg

JanJ

 

D

doug_newman

Well-known member

• Jun 25, 2006

• #5

I was leaning towards White-winged Tern. Both White-winged and Whiskered are very common at Marievale and the only other Tern one usually encounters is Caspian (although birds have wings).
Lookig at the differences in head pattern I was pretty sure it was White-winged but I was just interested in the fact that whith such a detailed photo, it is the first time I have picked up the bi-coloured primaries i.e. light grey outer webs and dark grey inner webs. Is this unique to White-winged or do both these Tern species have bi-coloured primaries in Juv plumage?

 

D

doug_newman

Well-known member

• Jun 25, 2006

• #6

According to our local field guides, Whiskered has a straight line through the eye onto the nape whereas White-winged's head pattern rises up to the crown behind the eye, not creating that straight line onto the nape. If that is correct I would have made this White-winged (also the lack of the slight reddish base to the bill?)

 

M

Mike Johnston

Well-known member

• Jun 25, 2006

• #7

doug_newman said:

According to our local field guides, Whiskered has a straight line through the eye onto the nape whereas White-winged's head pattern rises up to the crown behind the eye, not creating that straight line onto the nape. If that is correct I would have made this White-winged (also the lack of the slight reddish base to the bill?)

Click to expand...

I would say a moulting juvenile Whiskered. Remains of 'ginger' on mantle fit Whiskered. White-winged would have darker mantle, and it would show a darker carpal bar. Features you mention concerning cap and bill would be appropriate for an adult winter Whiskered, but photo correct for juvenile Whiskered.

 

JANJ

Well-known member

• Jun 25, 2006

• #8

Hi Doug.
As to head pattern:

http://www.sofnet.org/file/Huvven.jpg?Path=2&ID=944&File=Huvven.jpg

Upper is White-winged, left juv/1st winter, right winter.
Bottom is Whiekered, and same as above.

Notice the difference in head pattern and bill length/thickness.

JanJ

 

M

Mike Johnston

Well-known member

• Jun 25, 2006

• #9

Here's a pic of a juv. Whiskered. Pretty close to your bird I'd say, including head pattern. Bill is just reflecting light I think.

 

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