Date: 12/23/18 1:55 pm
From: David Irons <llsdirons...>
Subject: [obol] Re: White Egret
Noah,

This is a great post, particularly the inclusion of links to photos with Great Egrets showing gape extension that match up with what the Washburn Lane bird shows. The allure of a possible mega-rare bird in our midst invariably creates opportunities for self delusion. This overly optimistic delusion is usually manifests itself in the form of clinging to aspects of the bird that favor the rarity and ignoring, or not going looking for those aspects that create a counter argument. Seasonal and individual variations often explain birds not looking like what we expect them to look like. As you point out, the odds greatly favor this bird being a Great Egret that doesn't look quite right over it being an Intermediate Egret. Having seen this bird, I would be as happy as anyone if it proves to be the latter, but there are too many unanswered questions about this bird for me to be all-in and calling it such.

Most of the folks who have seen this egret (myself included) have little or no experience with Intermediate Egret. Further, how many of us have been closely studying the individual variation that we might see in Great Egrets? Great Egrets are relatively abundant birds that we see often and rarely in the context of trying to sort them out from other white herons/egrets. It is a species that we recognize instantly and don't have to study or look at closely to identify. Once we have a 'dog in the fight' (having seen the potential rare bird) it can become quite difficult to objectively filter information.

In recent weeks we have seen similar optimism in the case of the pale Snow/McKay's Bunting on Clatsop Beach. I suspect that many have already counted this bird as McKay's despite the reservations expressed by those who have far more experience with both species. Opinions–some extremely well-informed–that expressed dissent or uncertainty about identifying the bird as a McKay's seemed to gain little traction on OBOL amid all the hopeful optimism.

I would like to re-share (I know I've posted it before) a link to another informative post by David Sibley from several years ago. Sibley has often proven to be the cool head in the room when it comes to the mass hysteria that occasional grips the birding world (think "rediscovery" of Ivory-billed Woodpecker). In addition to presenting a great counter-argument to the Luneau videos being proof of Ivory-billed Woodpecker still being extant, he played significant role in revealing that a bird initially believed to be South Carolina's first Scott's Oriole was actually a far more expected Orchard Oriole. In the linked article below Sibley delves into the psychology of how we process observations of rare birds, especially once we are chasing a bird that has already been identified, or at least tentatively identified as a mega-rarity.

http://www.sibleyguides.com/2011/05/a-mystery-oriole-and-the-limitations-of-identification-by-impression/
A "mystery" oriole and the limitations of identification by impression - Sibley Guides - Sibley Guides - Identification of North American birds and trees<http://www.sibleyguides.com/2011/05/a-mystery-oriole-and-the-limitations-of-identification-by-impression/>
I agree with your analysis and conclusions but I think we lose sight of how limited their application might be. Most of what you say applies to static images, still photos certainly but as well perched or otherwise immobile birds.
www.sibleyguides.com

Dave Irons
Beaverton, OR



________________________________
From: <obol-bounce...> <obol-bounce...> on behalf of Noah Strycker <noah.strycker...>
Sent: Sunday, December 23, 2018 7:25 PM
To: Sally Hill
Cc: Alan Contreras; Jeff Gilligan; OBOL
Subject: [obol] Re: White Egret

Hi all,

I guess I have about as much experience as anyone on this list with Intermediate/Great egrets in other countries... which is to say I've wrangled with these birds a few times before, for better or worse ;)

First, it seems to me that gape extent is helpful as a supporting feature but can be very difficult to judge without a point-blank view (as others have pointed out). Facial feathers often obscure the narrowing rearline of the gape on Great Egrets, making it appear shorter than it really is. There are many images on eBird showing this variation. For instance, look closely at the gape on these Great Egrets, all photographed in the US in the past few days - none of them appears to project behind the eye:

https://macaulaylibrary.org/asset/130535571
https://macaulaylibrary.org/asset/130451321
https://macaulaylibrary.org/asset/129885791
https://macaulaylibrary.org/asset/129653601

As for our bird, I guess I would hazard a rather small/variant Great Egret, which incidentally is overwhelmingly more likely than a hemispherically misplaced Intermediate Egret. In Sally's last photo it shows the classic "kink" in the upper neck typical for a Great Egret, instead of the gently symmetrical S-curve an Intermediate should have, although even this field mark can be subtle. I've seen unusually small Great Egrets in Oregon before, and they are known to have significant size variation, especially between males and females; heavier birds may weigh almost three times as much as lighter birds according to published studies. All birds show individual variation, of course, and I can remember cases of confusingly small gulls and other species in the past. See this interesting post from Sibley:

http://www.sibleyguides.com/2012/01/do-dwarf-birds-exist/

It's probably safest to leave this bird simply as "white egret sp," at least for now. Remember also that not all birds are safely identified, no matter how loud some voices in the room. I still have no idea about the infamous white egret<https://ebird.org/view/checklist/S39201795> (seen by many) at Malheur - even after studying it for an hour from literally 10 feet away, it had almost-equal characteristics of Snowy Egret, Cattle Egret, and Little Blue Heron!

But to indicate that this discussion is settled, or that "experts" have called our bird an Intermediate Egret, is misleading and unhelpful, especially when detailed comments like the one pasted below (from the Facebook ID group, and the most informative perspective I've seen about this bird by someone who has really studied these species) are being offered:

Personally I wouldn’t ID this one as an Intermediate and from what I see, I would suggest that this is a runt Great egret. To me the bill looks too long for Intermediate for a start but it’s mainly some subtle details of the head that strongly point towards a Great egret. There is a noticeable difference in the size of the eye between the 2 sp, with Intermediate sporting a comparatively larger eye. Check out a few pics on the web (make sure they are correctly identified though...) and you’ll see it’s quite obvious once you have your eyes tuned into it: the eye of a Great egret appears tiny compared to Intermediate. The shape and colour of the loral bare skin patch is very useful and readily visible on the Oregon bird: it is somewhat narrow and thus looks rectangular rather than square. In Intermediate the loral patch is wider and thus appears square. The combination of these 2 features (eye size, shape of the loral patch) give to each sp a distinctly different facial expression once you know what to look for. I would also add that the lores don’t look especially yellow on the subject bird (rather greenish) and, perhaps more importantly, they sport at their bottom a black line that runs along the edge of the upper mandible: a typical feature of Great egret, as opposed to old world Great white egret, that was first brought to light by Sébastien Reeber as a possible feature that would help and separate nearctic birds from European birds. - Thibaut Chansac

Merry birding,

Noah Strycker


On Sun, Dec 23, 2018 at 9:12 AM Sally Hill <1sallyhill.9...><mailto:<1sallyhill.9...>> wrote:
I have been following that discussion. Interesting.

Sally Hill


On Dec 23, 2018, at 9:04 AM, Alan Contreras <acontrer56...><mailto:<acontrer56...>> wrote:

Questions about the face pattern have been posted on the Advanced Bird I.D. page on Facebook. I’m not going to copy and paste the comments but those who are interested should check it out.


Alan Contreras
<acontrer56...><mailto:<acontrer56...>
Eugene, Oregon

www.alanlcontreras.com<http://www.alanlcontreras.com>


On Dec 23, 2018, at 8:55 AM, Jeff Gilligan <jeffgilligan10...><mailto:<jeffgilligan10...>> wrote:

If the published sources are correct, and the identification criteria as reported on chat sites by “experts” who live within the range of Intermediate Egret are correct in their comments, this is an Intermediate Egret.

Unless the identification criteria is shown to be inaccurate, I will refer to the bird as an Intermediate Egret.

Thank you for the additional photos. They are of plenty good enough quality to see the crucial identification factors.


Jeff Gilligan



On Dec 23, 2018, at 9:34 AM, Sally Hill <1sallyhill.9...><mailto:<1sallyhill.9...>> wrote:

I overlooked two photos that have the next more extended.
Here is link. https://ebird.org/view/checklist/S50848667

Sally Hill
Eugene Oregon




 
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