[texbirds] NW Austin (Travis and Williamson Cos.) 11/28/12 - possible Great Black-backed Gull at Lake Travis?

From: Rich Kostecke <rkost73@xxxxxxxxx>
To: Texbirds <texbirds@xxxxxxxxxxxxx>
Date: Thu, 28 Nov 2013 18:57:35 -0800 (PST)
I birded several NW Austin (Travis and Williamson Cos.) locations this morning. 
 My first stop was the Highway 360 bridge over the Colorado River (i.e., the 
Pennybacker Bridge).  I keep hoping to pick up Bald Eagle and Ringed Kingfisher 
there for my patch, but no luck.  However, there was a fairly impressive gull 
flight going up river.  Among the 914 Ring-billed Gulls that passed over, I was 
able to pick out a single Franklin's Gull.  My second stop was Lake Travis Bob 
Wentz Park at Windy Point.  The park was pretty birdy (I tallied 50 species) 
with 5 species of duck (dominated by Gadwall), 2 Common Loon, 4 Eared Grebe, 2 
Osprey, 333 Ring-billed Gulls (the first sizable number of gulls I have 
observed at the lake this fall), 1-2 Herring Gulls (at least I was assuming 
they are both Herring Gulls - more on this in a bit), 1 Merlin, and a good 
number and diversity of non-water birds (including 1 Yellow-bellied Sapsucker, 
1 Blue-headed Vireo, 1
 Blue-gray Gnatcatcher, 2 Golden-crowned Kinglet, and 3 Pine Warblers).  
In regards to the Herring Gulls, I wouldn't mind a second opinion.  I have been 
pondering over them all day (I guess I am a bit out of practice on my gulls).  
I have posted some poor pictures taken at a distance and into the sun that I 
have heavily cropped and enhanced (i.e., lightened) - < 
http://www.flickr.com/photos/kostecke/sets/72157638159497315/ >.  Anyway, it 
may just be my imagination, but now as I look at the pictures, the bigger one 
seems really big in comparison to the other gull, particularly in the pictures 
labelled "gulls4" and "gulls5".  The gulls in those pictures are definitely not 
Ring-billed Gulls.  In the picture labelled "gulls3", both of the gulls in 
question (to the right) look bigger than the Ring-billed Gull on the left.  Of 
the ones on the right in gulls3, the one in the foreground still looks smaller, 
but not as dramatically smaller as in the other pictures, but perspective can 
sometimes be tricky when it comes to judging
 size.  Anyway, maybe it is my imagination, but I am wondering now if the 
larger one might be a 1st winter Great Black-backed Gull?  The size, hefty 
bill, and white rump in flight (gulls6, gulls7, gulls8) might be consistent 
with that ID.  Then, the one in the foreground (in gulls4 and gulls5) would 
seem to probably be a 1st winter Herring Gull (the bill looks maybe a little 
too bi-colored, more like on a 2nd winter bird, but the brown rump in flight - 
see gulls8 - would seem to be consistent with a 1st winter bird).  Anyway, let 
me know what you think.  Other than those 2 gulls being bigger and darker than 
the Ring-billed Gulls, the ID isn't as straightforward as you might think 
(Great Black-backeds can overlap in size with Herrings), especially as you 
start looking at those 2 gulls and seeing subtle to not so subtle differences 
in size, proportion, bill size and shape, etc.

In Williamson County, I had a Merlin at the office park at 7700 Parmer Lane.  
Along McNeil-Merriltown Rd., I had 1 Pine Warbler and 1 Harris' Sparrow as 
highlights (though, I made a typo when inputting my data into eBird which seems 
to have caused a minor ruckus from what I have heard - I had 7 Lesser 
Goldfinches, NOT 7 Lawrence's Goldfinches; the typo is fixed now, but not 
before a bunch of rare bird alerts went out on it).

Happy Thanksgiving!

Rich


 
Richard Kostecke, Ph.D.
The Nature Conservancy
318 Congress Ave., Austin, Texas 78701
Email: rkost73@xxxxxxxxx or rkostecke@xxxxxxx
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[texbirds] NW Austin (Travis and Williamson Cos.) 11/28/12 - possible Great Black-backed Gull at Lake Travis?

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