You very well might have the answer….
On Sep 14, 2017, at 9:06 AM, Brodie Lewis <brodietlewis@xxxxxxxxx> wrote:
Nate Swick found this paper on two accepted records of CAEG x LBHE hybrids
(apparently he has some thing called "Google"). As noted, the hybrid
individual showed the smoky tipped primaries that none of the hundreds of
other cattle egret fledglings had.
To my novice mind, the bird in question shows certain features that only make
sense for CAEG, and others that should be disqualifying, so the hybrid idea
is compelling.
Paper can be found here:
https://www.researchgate.net/profile/Lawrence_Igl/publication/316881260_Observations_of_Little_Blue_Herons_nesting_in_North_Dakota_and_an_instance_of_probably_natural_hybridization_between_a_Little_Blue_Heron_and_a_Cattle_Egret/links/5915cc5caca27200fe500e0c/Observations-of-Little-Blue-Herons-nesting-in-North-Dakota-and-an-instance-of-probably-natural-hybridization-between-a-Little-Blue-Heron-and-a-Cattle-Egret.pdf
<https://www.researchgate.net/profile/Lawrence_Igl/publication/316881260_Observations_of_Little_Blue_Herons_nesting_in_North_Dakota_and_an_instance_of_probably_natural_hybridization_between_a_Little_Blue_Heron_and_a_Cattle_Egret/links/5915cc5caca27200fe500e0c/Observations-of-Little-Blue-Herons-nesting-in-North-Dakota-and-an-instance-of-probably-natural-hybridization-between-a-Little-Blue-Heron-and-a-Cattle-Egret.pdf>
Brodie
Maupin
On Sep 13, 2017 08:18, "Brodie Lewis" <brodietlewis@xxxxxxxxx
<mailto:brodietlewis@xxxxxxxxx>> wrote:
One thing that stuck with me from looking at the birds was that while they
weren't easy ID's, they're also noticeably different from each other. The
"cattle" is noticeably smaller with a shorter, more yellow bill. If there was
a hybridization and they were nest mates, this would be possible, I suppose?
The other thing I noticed is that when I was watching them, it was the LBHE
that was harassing the CAEG (I'm just using these as labels, as I agree it
can't be considered a pure cattle egret), the opposite of what Matt observed.
I even have a photo of the larger bird nipping at the smaller one.
For the more reliable heron experts out there: I could see the smaller bird
being of mixed parentage, as it seems to show traits of different birds, but
is there any reason to suggest the larger bird is anything other than pure
LBHE?
Maybe they are nest mates, but brothers from a different mother, or sisters
from a different mister...
Brodie
Maupin, Or
On Sep 13, 2017 00:51, "Tim Janzen" <tjanzen@xxxxxxxxxxx
<mailto:tjanzen@xxxxxxxxxxx>> wrote:
Dear Matt,
In my opinion, the dusky blue coloration in the wings seen in photo
ML68686581 at http://ebird.org/ebird/view/checklist/S39142883 ;
<http://ebird.org/ebird/view/checklist/S39142883> trumps the fact the bird
has black on the legs. I don’t think that a Snowy Egret can ever show as
much blue coloration as is seen in the bird in this photo. There are other
features on this bird that also suggest LBH. The overall bill coloration and
the thickness of the bill are also strongly suggestive of LBH and not of
Snowy Egret. The legs of the bird in photo ML68686611 seem consistent with
LBH in my opinion. They are basically greenish yellow. The bill coloration
in photos ML68686611 and ML68686621 is also consistent with LBH. Another
reference that reviews field marks for immature Snowy Egrets and Little Blue
Herons is Ken Kaufman’s book “Advanced Birding”. In that book on p. 35 Ken
states that “The plumage of Snowy Egret is all white at all stages, but the
Little Blue is never pure white: even in the youngest immature the tips of
the outer primaries are gray.” I see no reason to think that either bird
(assuming that two different birds were photographed) must be a hybrid. I
think that light conditions are making the bill of the bird in ML68686611
appear more yellow than it really is. The photo appears to have been taken
late in the afternoon. The bill is far too long for a Cattle Egret.
Sincerely,
Tim Janzen
From: Matt Cahill [mailto:matt.c.cahill@xxxxxxxxx ;
<mailto:matt.c.cahill@xxxxxxxxx>]
Sent: Tuesday, September 12, 2017 11:12 PM
To: Shawneen Finnegan
Cc: Jeff Gilligan; Tim Janzen; OBOL
Subject: Re: [obol] Re: Malheur Narrows Egrets
Hi all,
I went back out to see the hegrets this afternoon, to watch them interact and
take a few more photographs. I expected to confirm my doubts about the
(potential) little blue, instead I walked away doubting the (potential)
cattle egret even more. Back home in Bend, I read this thread and some
additional resources and developed my own theory. Read on if you're still
enjoying this ID challenge as much as I am.
David Sibley has a very helpful article (I think) on differences between
snowy egrets and juvenile little blues, the only difficult heron ID in his
opinion. The article is here:
http://www.sibleyguides.com/2012/08/distinguishing-immature-white-little-blue-heron-from-snowy-egret
<http://www.sibleyguides.com/2012/08/distinguishing-immature-white-little-blue-heron-from-snowy-egret>
He writes extensively about how habit is a very useful ID trait. In short
summation, both of the mystery hegrets behave much more like little blues
than snowies (so I think). But more definitively, Sibley writes that little
blue heron "wingtips show small dark gray tips on outer primaries...[and] are
diagnostic". Both birds do show this trait in some of my photos, one more
extensively than the other. See the fourth photo from yesterday's checklist
(I added more from my SLR): http://ebird.org/ebird/view/checklist/S39142883 ;
<http://ebird.org/ebird/view/checklist/S39142883>
Sibley continues that the "presence of black [on the legs] is diagnostic for
Snowy Egret, as is contrasting yellow feet." Both birds show nearly identical
leg and foot coloration: a complex pattern of yellow and black. But
definitely black. See today's checklist for a good comparison:
http://ebird.org/ebird/view/checklist/S39154699 ;
<http://ebird.org/ebird/view/checklist/S39154699>
These two traits are contradictory. Both birds have 'diagnostic' qualities of
both snowy egrets and little blues, with habit supporting LBH's. But to
further complicated it, the 'cattle egret' individual has a very yellow bill
which if looked at in isolation (along with the surrounding gape) looks very
much like a cattle egret, to me. Sibley writes that snowies have a "bill
usually darker [than LBHs] with blackish on culmen extending back close to
forehead". Sifting through Google Images, I can't find any photos of LBH's or
Snowies of any age having such a yellow bill as the 'cattle egret'
individual.
Interestingly, it is easy to find pictures of juvenile Cattle Egrets with
similar leg patterns as both of our individuals. Which leads me to a theory
I'll offer. Could it be that both of these birds are Cattle Egret x Little
Blue Heron hybrids? Such a hybrid could show the same leg and foot pattern,
wing pattern, and variety of bill shapes and colors as our friends at the
Narrows. Could it be even further that these two birds are nest mates? It
doesn't seem completely beyond logic that a little blue and a cattle egret,
both near the edge of their range and finding no appropriate mate instead
found each other. Then their offspring found an incredible bounty of dying
carp at the Narrows. I could be reading into it, but the birds seem to like
each other, in a sibling rivalry kind of way!
In short, I don't see how we can claim either bird is a pure Snowy Egret,
Little Blue Heron or Cattle Egret, at least not based on resources I've
found. A far-flung Asian species is exciting, but seems harder to stick than
a native hybrid. Putting the pieces together, this is the outcome I've found.
Would love other's thoughts.
Thanks for reading!
Matt Cahill
Bend
