A Brushup "Primer"
for Correctly Identifying Neotropic Cormorants.
NECOs historically seen in Northern Utah have been predominantly
Juveniles or Non-breeding Adults.
What do we have here?
What determines this?
1) Gular Angle, with NECOs having a "V" shaped gular; and
DCCOs having a "U" shaped gular
2) No yellow lores (unless feathered!)
The DCCO inset illustrates yellow lores/bare skin!
The NECO below illustrates yellow lores+feathers!
What else to look for:
It has been my experience that observation of a pink gular sac (if extended) is a "slam-dunk" positive for NECOs OF ALL AGES!
In DCCOs, their extended gular sac is yellow-orange.
(more on this at a later time)
Here we see another specific feature for positive I.D. of
ADULT, BREEDING PLUMAGE NECOs
as seen with the bird in the foreground, and its "V" gular being ridged with white feathers, continuing toward the back of the head.
The NECO behind is a non-breeding example.
Adult Breeding NECOs in Northern Utah have been in the minority.
Here we see 2 of them on the tiny island at Sandy Pond.
The final Litmus Test for NECO I.D. is SIZE DIFFERENCE when both species are seen together!
NECOs are typically approximately 1/3rd smaller.
The example below has even more merit, with the NECO being in
(Double-Crested on left; NECO on right)
I have coined the term,
"1st Spring Neotropic Cormorant" for birds such as the following that possess a unique yellow eye-ring!
A close-up of the bird's head showing the eye-ring and the
FEATHERED yellow lore, distinguishing it from DCCOs with yellow lores of skin.
Mill Race Pond continues to be on my birding circuit, beginning in May of 2010, when I discovered 7 Neotropic Cormorants there, to the present time.
During the time from May through October, 2010, being retired, I studied NECOs extensively there, constantly available, numbering anywhere from 2 to 7 individuals.
I also studied another source of NECOs I discovered that year which put Sandy Pond on Utah birders' radar for the 1st time.
In my studies, I succeeded in capturing a wide variety of images of NECOs behavior, such asSocial Signaling; thermo-regulation; courtship; breeding...etc.
For what I'm about to say to make sense, it must be emphasized that historically, I.D. of juvenile NECOs has been confusing for many, due to the presence/absence of 'yellow lores'.Field guides reported: "Neotropic Cormorants NEVER have yellow lores!"
This PDF field guide by Cin Tee Lee, debunks this myth, as does my own documentation: http://www.ruf.rice.edu/%7Ectlee/Cormorant.pdf
After becoming aware of the distinction between NECO pink gular pouch coloration and DCCOs yellow/orange gular pouches, it occurred to me that gular pouches could assist in I.D. of NECOs, especially in clarification of juveniles thought to be Double Crested cormorants.
In conversation with David Sibley, he said, "I was not aware of any color difference but it looks like you have documented it pretty thoroughly."
Fast forward to the present:At Mill Race Pond, I succeeded in capturing an image that documents both NECO and DCCO gular color display simultaneously.Finding Neotropic Cormorants alone in Utah is rare; photographing them together with Double Crested Cormorants more rare; and seeing them simultaneously in the act of gular display… what are the odds?!
March 3, 2013
Neotropic Cormorant at Mill Race Pond continues...
This time, fate provided me with the direct comparison of
Left: Neotropic Cormorant,
Right: Double Crested Cormorant
The following image is
ONE FOR THE BOOKS!
I've written considerably, with visual evidence, about
the significance of gular pouch coloration differences
between NECOs and DCCOS.
Today I succeeded in capturing BOTH SPECIES
IN THE SAME FRAME,
DISPLAYING THEIR GULAR POUCHES!
This image reinforces my postulate:
PINK gular = NECOs
What's the significance of pink gular sacs/NECO characteristic?
When Juvenile Cormorants possess "yellow lores" (such as is seen in "1st Spring NECOs"), it has been assumed
they are Double-Crested cormorants!
(see this Field Guide PDF by Cin Tee Lee, who debunks this myth:)
Below we see a 'First Spring Neotropic Cormorant'
(distinguished by itsYellow Eye Ring)
standing left of another NECO (BOTH SAME SIZE).
Some would label this bird a juvenile DCCO!
Sandy Pond, 2010
However, notice when the juvenile becomes agitated, it
by displaying its
PINK GULAR SAC!
Roll your cursor over this image to see the result!
Sandy Pond, 2010
FOR ADDITIONAL GRAPHIC HELP IN DETERMINING NECOs FROM DCCOs,
Go to this link,
an interactive page showing species and age differences side-by-side!