Fwd: [CB] RE: [nwcalbird] Re: [CALBIRDS] Red-legged Kittiwake-Del Norte County
- Rob asked this to be forwarded.
Begin forwarded message:
> From: MigratoriusFwlr@...Steve Rovell
> Date: Mon Mar 10, 2003 10:49:38 PM US/Pacific
> To: smca@... ("Sean")
> Cc: jmorlan@..., feignervogel@...,
> Â Â email@example.com, firstname.lastname@example.org
> Subject: [CB] RE: [nwcalbird] Re: [CALBIRDS] Red-legged Kittiwake-Del
> Norte County
> Sean and others, Sorry for the cross posting. (This is somewhat
> of a lengthy message so bear with me).It is now apparent that I have
> made a mistake in aging this Kittiwake. After looking at some other
> sources I, and Brooke Mcdonnel, both came up with the conclusion,
> (independently from one another), that this bird is a 2nd
> winter/winter adult bird. So sorry about the mistake. A boo-boo that
> should have been apparent with the features that were presented on
> this bird but excitement and nervousness of finding such a
> mega-rarity overrode my thought process. Rookie move anybody? Here's
> why I now think that this bird was a 2nd winter/winter adult:
> 1st point: bill color- I am bringing up this point 1st since this is
> the feature that was brought into question by Sean Mcallister. The
> bird definitely had and all yellow bill, which according to Harrison's
> seabirds, and the North American Bird (reference set?), points
> towards 2nd winter/winter adult. But, Sibley's illustration has a 1st
> summer bird with an all yellow bill with a black tip? The Nat. Geo 4th
> ed. illustrates a bird with a all yellow bill? P.J. Grant states that
> the yellow bill is aquired by 1st summer plumage. Interesting indeed.
> I smell an identification paper brewing. Just to state again this bird
> had an all yellow bill.
> 2nd point: leg color- The bird that I saw had bright red legs. It was
> the "coral" color that Sibley calls it. Brooke had a different opinion
> as far as this is concerned, thinking it was more "reddish". But she
> also admitted that I have better eyes then here and people do perceive
> colors differently. Correct me if I am wrong but I think that with the
> combination of red legs and an all yellow bill there is no question to
> the identification of the bird. But I am not basing the i.d. only on
> these 2 features. That would not be good birding skills put to work
> for such a mega-rarity. Also, just a note on leg color for
> Black-legged Kittiwakes- the best source I found on this topic was in
> P.J. Grants book. He stated that 1st winter Black-leggeds can
> sometimes have flesh to orange-flesh and rarely bright pink or
> orange-red legs. Harrison's book states that some BLKIs can have
> reddish legs but no age was given. Sibley states that some BLKIs
> (especially 1st year birds) can have pink, yellow, and even orange-red
> legs. So I must pose a question: What is the exact idea behind the
> range of coloration of legs of BLKI and is that rare feature only on
> 1st year birds? There was a paper published in British Birds in 1959
> by a person by the name of J.C. Coulson that I think can shed some
> light on this topic. The title of the paper was "The Plumage and Leg
> Colour of the Kittiwake and Comments On the Non-breeding Population".
> 52: 189-196. I tried to find it here at Humboldt State but there
> records only go back to the 60's. If somebody has better access to
> this paper can somebody check it out and post their findings.
> Other features: bill length: the bird definitely had a shorter bill
> than neighboring Black-legged Kittiwakes. This was apparent 300 meters
> away looking through my Kowa 82 mm scope at 60x. Also the bill
> appeared to, me at least, not having as long of a decurved culmen as
> the Black-legged Kittiwakes that is was associated with. It also
> seemed to have a more rounded, blunt- shaped tip. This feature of bill
> length was one that Brooke said she definitely noticed. Some of the
> sources that I consulted also noted that the depth of the bill should
> be a little bit thicker. This I did not notice. Brooke, who went to
> Humboldt State University, where we both attend, did numerous
> measurements on the bills of numerous specimens of Black-legged
> Kittiwakes (adults and immatures) and 3 specimens of Red-legged
> Kittiwake (all adults ) and noted that there was a strong difference
> in the depth of the bill with the Red-leggeds all having thicker
> bills. Another note on bill length difference. Most of the kittiwakes
> that I got to compare the Red-leggeds bill to were adult birds.
> American Birds species accounts stated that there were culmen
> measurments taken of breeding Red-legged/Black-legged Kittiwakes on
> the Pribilofs and Bouldin island and Red-legged max=32.5 mm and
> min=22.6 while Black-legged had a max=45.5 mm and a min of 33.5 mm.
> Since this was during the breeding season I assume that these were all
> adult birds that were measured.
> Head shape and coloration: The bird, in relation to the other birds,
> had a somewhat different shaped head with a somewhat steeper forehead
> and flatter crown. The size of the bill also gave the impression of a
> smaller headed bird. The head was white with a grey ,smudgy, ear spot,
> and a greyish nape which turned into a darker grey half collar on the
> back of the neck. These features were subtle but evident on the bird
> when next to the Black-leggeds. To me there was some difference in
> coloration of the spot and collar in relation to the Black-leggeds. I
> think, though, that if this bird was alone this feature would not have
> much validity since there would be nothing to compare it to.
> Mantle color: The bird had a slightly darker mantle (1 to 2 shades). I
> saw the bird at all angles and with the overcast skies this feature
> did not seem to change with the birds movement. Of course if it was
> seen alone I would think that this point would lose its validity
> pretty fast.
> Leg length: In some of the sources (Sibley illustrates it well) it was
> stated that Red-legged Kittiwakes have shorter legs than Black-legged
> Kittiwakes. This feature was one that I unfortunaetly spent little
> time with although a few times I had the impression that the birds
> legs were indeed shorter than the neighboring Black-leggeds.
> Overall the bird seemed to be slightly smaller than the Black-legged
> Kittiwakes. Conclusion: I believe that this is indeed a Red-legged
> Kittiwake that was in 2nd winter/winter adult due to the combination
> of both bill color, length and shape; shape of the head; leg
> coloration and length, overall size and color of the mantle. If there
> are some skeptics out there, which there should be, please feel free
> to e-mail me privately.
> Just a note to others today: I haven't heard if anybody had
> successfully seen the bird today so I assume not. Also Elias Elias put
> a message on th North western Cal. bird box stating that he did see a
> Black-legged kittiwake with some red tags (bands?) on its legs and had
> a dark carpal bar on its wing. This was definitely not what we saw,
> (just for those skeptics out there). Anyways, I am beat from studying
> up on this bird and need to get some actual school stuff done. If
> anybody wants to discuss this bird with me feel free to e-mail me
> privately. I would love to hear other peoples ideas and comments. Take
> care and good luck to those who look for the bird.
> Oh, one more question.... What was the ages of the 2 accepted records
> for California and the 1 for Nevada? Joe you probably know this one. I
> know that there is a record for Washington also (which Brooke was
> lucky enough to see) which was of an adult bird.
> Rob Fowler
> P.S. Can somebody post this to Calbirds I am still having problems
> with it. Thanks in advance.
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