Common Tern ID

To: Mike Carter <>, BIRDING-AUS <>
Subject: Common Tern ID
From: jilldening <>
Date: Wed, 15 Jan 2003 05:12:46 +1000
Hi Mike,

Thanks for the reply. I have thought further about this bird, prompted in
part by the generosity of others in sharing their experience with me. I
could not make this bird into an Arctic Tern, as it appeared, from my
memory, to have legs of equal length to the Commons around it. Nor was I
happy with Roseate, although Paul O'Neill explained that young Roseates can
show a dark carpal bar. And I didn't get a look at the back end.

After some thought, I am still locked into the Common Tern ID. What was so
different was the blinding brightness of the bill and legs.

I have seen many examples similar to the bird you described below, and I
agree with every feature you have noted pointing to a Common in the last
stage prior to showing full breeding plumage. I find it interesting that the
bird below had already replaced its outer primaries by 4/2/02. Last Saturday
was 11/1/03, and at that point I noticed that not one single Common Tern had
yet replaced its outer primaries. We are in that critical period in between.

In contrast, almost all of the Little Terns have replaced all their outer
primaries, with just the odd one still showing worn primaries. And yet it is
still rare to find a Little Tern yet showing any yellow on its bill. It is
only days away though. I saw the first show of yellow on a Little Tern bill
on 2/1/03, but it is still a rare sight.

Mike, I have suddenly remembered something else about the tern I saw in
Caloundra, and which made quite an impression on me at the time - how could
I have forgotten? My apologies. I was managing a group at the time, and
didn't have time to write down what I was noticing. (Now there's a lesson to
us all.) There was a show of white bare part between the eye and the black
of the surrounding feathers. A thin white line in the lower rear of the eye
surround, as in the Common or Black Noddy. Have I shifted the goal posts?


Jill Dening
Sunshine Coast, Qld
26º 51'     152º 56'
Ph (07) 5494 0994

> From: "Mike Carter" <>
> Date: Tue, 14 Jan 2003 11:56:07 -0000
> To: "jilldening" <>, "BIRDING-AUS"

> Subject: Re: [BIRDING-AUS] Common Tern ID

> I agree your bird is a Common Tern, possibly of the nominate subspecies
> hirundo. However, because on the breeding grounds in Siberia, there is a wide

> The day Jill posted her query, I received a letter with photos from Rob
> Drummond with a similar problem. They were terns taken at Ricketts Point in
> Port Phillip Bay on 4.02.02. Rob was confident that a black billed, red legged
> bird with black primaries, dark carpal bar and partially black, irregular
> shaped, non-breeding plumaged, crown (not extending to nape), was a Common
> Tern. This, I understand, was typical of others present. His query bird had a
> black bill, black (possibly tinged red) legs, white forehead but remainder of
> crown to nape black, no carpal bar, grey, not black primaries and long tail
> streamers extending to tip of folded wings. I consider this was an adult
> Common Tern of the race longipennis in almost full breeding plumage, needing
> only a black forehead, a darker belly and perhaps some moderation in colours
> of bare-parts to complete the process.
> A bird so nearly in breeding plumage in early February is very advanced.
> According to fig. 1 in HANZAB, head moult should not start till February and
> one might assume that the outer primaries should be in moult rather than
> complete. Perhaps the data used was more relevant to hirundo than longipennis.

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