Proposal (849) to South American Classification Committee
Add
Vireo gilvus (Warbling Vireo) to main list
A single Vireo gilvus was photographed at Jardín Botánico de Quito, Ecuador, by Roger Ahlman (Freile et al. 2019; https://revistas.usfq.edu.ec/index.php/reo/article/view/1277) on 11 April 2017. This bird was first heard calling, later observed and photographed. It responded to playback of nominate subspecies and approached, letting Ahlman to secure a few photographs. This observation was carefully studied by the Comite Ecuatoriano de Registros Ornitologicos (CERO), and it received unanimous votes for acceptance. The dull tone of upperparts, dull buff on underparts, poorly outlined, fairly broad whitish supercilium (and calls) were good characters for V. gilvus.
This is the first documented record for Ecuador and
South America.
Reference:
Freile, J. F., A. Solano-Ugalde, D. M. Brinkuizen, P. J. Greenfield, M. Lysinger, J. Nilsson, L. Navarrete & R. S. Ridgely. 2019. Fourth report of the Committee for Ecuadorian Records in Ornithology (CERO) and a revision of undocumented and erroneous records in the literature. Revista Ecuatoriana de Ornitología 5: 52–79. https://revistas.usfq.edu.ec/index.php/reo/article/view/1277
Juan Freile, March 2020
Comments from
Robbins: “NO. This appears to be
based solely on photographs and a very poor (I'm not certain I can detect a
vireo) audio recording attached to an eBird checklist.
“1)
From the photos in the publication one cannot distinguish a worn Brown-capped (Vireo
leucophrys) from a worn Warbling Vireo -- based on my examination of skins
in the KU collection. Note that this was
in April.
“2)
The audio recording offers nothing in support of the identification. Vireos are notorious in responding to
non-specific vocalizations (pers. obs.).
“3)
The only way that I would accept a record of gilvus in South America is
to either have genetic data or have a bird with one or more of the following
data: banded/geolocater/transmitter.”
Comments
solicited by Remsen from Dan Lane: “I disagree
with Mark that this bird cannot be identified to Warbling Vireo with
confidence, and feel he is being a far too conservative with his criteria for
accepting a record of the species in South America. Comparing the photos of the
bird in question:
|
“With photos of Vireo
leucophrys from Ecuador:
https://ebird.org/media/catalog?taxonCode=brcvir1&sort=rating_rank_desc&mediaType=p®ionCode=EC
|
two things jump out
immediately.
“1)
the species name of V. leucophrys wasn't an accident! The glowing white
supercilium contrasts strongly with the eyeline and crown in *every* photo in
this series. Furthermore, the crown has a distinctly dark brown (again, a
character highlighted in the English name of the species) lower edge where it
meets the supercilium, exaggerating the pale eyebrow effect, and almost
suggesting the black line present there on V. olivaceus. These
characters are missing from the bird in question from Quito.
“2)
in the photos of V. leucophrys, there is a strong hint of the warm
yellow wash to the underparts contrasting with the whiter throat, even in the
most faded or least-saturated. This does not appear in the photos from Quito,
where the underparts are fairly uniform buff, with no suggestion of yellow.
“The states of both of these
characters in the photos from Quito are consistent with Warbling Vireo, and not
with Brown-capped.
“I would agree that the
response to playback and the recording made are not strong characters for
conclusive ID to Warbling Vireo, but I can at least say that the vocalizations
in the recording are of a member of the V. gilvus/leucophrys
complex, and are calls given by V. gilvus.
XC182706 Warbling Vireo (Vireo
gilvus)
|
XC105673 Warbling Vireo (Vireo
gilvus)
|
“Personally, I feel
absolutely confident that this record is correctly identified as Warbling
Vireo, and would be willing to accept it as the first record for South America.
Whether it represents a member of the eastern nominate subspecies or western swainsoni-group
may not be determinable from the evidence, although obviously likelihood would
favor nominate.”
Comments
from Jaramillo:
“YES. I was going to say no, based on
the fact that the looking at the photos in the publication, the color tones are
just off to me. A darker cap above the
supercilium is not unusual in Warbling Vireo, but the tones there are usually
gray toned, olive with a gray wash. This
bird, at least in the photo, looks mid brown. But then I saw that the eBird
checklist has additional photos, and particularly the one where it is sallying
to get a bug, is 100% Warbling Vireo. Here are the additional photos: https://ebird.org/checklist/S35871298”
Comments
from Claramunt:
“NO. I think the evidence is insufficient.”
Comments from Areta: “YES. After carefully
studying the photographs and refreshing my experience with V. leucophrys, I think that the bird in the pictures is V. gilvus. I can hardly listen to what
is being made by the bird in the recordings, so I cannot comment much on this
front.”
Comments from Pacheco: “YES. Based on the comments and
examination of the additional evidence I accept that there are reasons to agree
to the identification.”
Comments from Bonaccorso: “YES. I think Dan Lane's
examination is adequate and justifies the inclusion of Warbling Vireo in
the list. Mark, I think we cannot be as conservative as we used to be. These
cases will surely increase in frequency as climate patterns keep changing.”
Comments from Dan Lane (who has Stiles’s vote on this one): “Yes to
accepting to vote in Gary's place in this instance, and YES to accepting Vireo
gilvus onto the SACC list for South America.”
Additional comments from Robbins: “I looked at the
additional photos that are in the eBird checklist and I’m not convinced any of
the photos demonstrate that the bird has a gray crown vs. a brown crown. As I mentioned before, at this time of year,
both species should not be in fresh plumage. We have specimens of leucophrys in our
collection (but not from Colombia or Ecuador) that are worn and have very
little yellow on the flanks; they appear very similar to worn gilvus.
“So, in my opinion, what is needed is a comparison of birds from
the pertinent time of year and location.
As a result of Dan’s comments, on May 8th, I emailed Nate
Rice at ANSP, where there are pertinent specimens, i.e., specimens of leucophrys
from Colombia/Ecuador during the appropriate period. Unfortunately, Nate still does not have access
to the specimens. I presume that is also
the case for other museum colleagues. Thus, I plan to stay with my original
assessment until others can examine specimen material and offer their
assessments.”