Help with Ibis Identification - Cancun, Mexico (1 Viewer)

[Glaverty]

In mid-November, 2019, on two days at a resort south of Cancun, I took photos of a juvenile ibis. After looking at the expected species in the area, I entered them into eBird as Glossy Ibis. A few weeks later, I received a note from the eBird reviewer indicating that the bird was actually a White-faced Ibis (distinguishing feature that he mentioned was the red eye colour). As requested by the reviewer, I changed my identifications on two checklists to White Faced Ibis. From what I can tell from eBird, this would be only the second eBird observation for this species in Quintana Roo province. When I subsequently looked on eBird, my observations have been supressed (the photos are marked 'unconfirmed'). Unfortunately, I didn't keep the email from the eBird reviewer (and any attempts to get intervention / explanation from eBird have been fruitless). ). I am starting to wonder if my original identification of this bird (as Glossy Ibis) was correct. Am attaching the photos below and would welcome any comments from birders with experience in Ibis identification.

 

[Andy Adcock]

1st year Glossy.

 

[Butty]

1st year Glossy.

And the reddish iris...?

 

[KC Foggin]

Beautiful images of this Glossy Ibis and nicely captured Glaverty!

 

[Andy Adcock]

And the reddish iris...?

It can only be one of three and it's not Green so what do you think it is and why, eye looks brown in the last shot.

White-faced and Glosy may not be seperable in some cases at this age.

 

[Microtus]

The reddish eye should make it a White-faced Ibis.

 

[Butty]

eye looks brown in the last shot.

I'd go for reddish-brown, and red-brown in most of the others.

The reddish eye should make it a White-faced Ibis.

This is my understanding, and I've never seen a definitive statement to the contrary - but I have in the past found differentiation of non-obvious glossy/white-faced ibises problematic, so I'm cautious.

 

[Microtus]

Maybe it is a hybrid?

 

[Andy Adcock]

I'd go for reddish-brown, and red-brown in most of the others.


This is my understanding, and I've never seen a definitive statement to the contrary - but I have in the past found differentiation of non-obvious glossy/white-faced ibises problematic, so I'm cautious.

Wouldn't you expect a bird whose eyes had effectively become adult, to at least be showing some signs of developing the adult face pattern?

 

[Butty]

Wouldn't you expect a bird whose eyes had effectively become adult, to at least be showing some signs of developing the adult face pattern?

Definitely not. They might do, but in birds in general such a link is absolutely not to be expected/assumed.
My understanding is that white-faced ibis has a red(dish) iris at all ages.

 

[Andy Adcock]

Definitely not. They might do, but in birds in general such a link is absolutely not to be expected/assumed.
My understanding is that white-faced ibis has a red(dish) iris at all ages.

I don't think that's true.

'III. In juvenile and first-basic plumages (first summer, fall, and winter) both species have a dark eye and no color to the face for an extended period; thus some cannot be identified in the field. It is important to realize that dark ibises observed in fall and winter may well be young birds and should be recorded as “Glossy/White-faced Ibis” in eBird and elsewhere unless some definite identifying feature can be seen. That said, some of them may become identifiable during this period:'

At this link.

Dark Ibis Identification - Missouri eBird

Dark Ibis Identification: Identification of the two dark ibises (genus Plegadis) can range from easy to impossible, depending on their plumage stage. In most parts of Missouri, White-faced Ibis (Plegadis chihi) is more regular and numerous than Glossy Ibis (Plegadis falcinellus), but they cannot...

ebird.org

 

[Butty]

Maybe it is a hybrid?

Option of last resort. It's far more likely that we (or those contributing so far, me included) just don't know enough to be certain-sure about how to separate problematic glossy/white-faced ibises. Or that it is a white-faced ibis.

 

[Butty]

'III. In juvenile and first-basic plumages (first summer, fall, and winter) both species have a dark eye

Good researching - and that's fair enough - and far from being surprising... But this bird does have a reddish iris, which (as far as I'm aware??) glossy ibis never has (I'm delighted to be corrected on that). Which makes it white-faced ibis - apparently! (I'll ignore that source's gross mis-use of the term 'first summer' there.)

Note:

dark ibises observed in fall and winter may well be young birds and should be recorded as “Glossy/White-faced Ibis” in eBird and elsewhere unless some definite identifying feature can be seen. That said, some of them may become identifiable during this period:'

This one has become identifiable - apparently. Or it's an adult - although the grey (not pink) facial skin seems to make it a 1st-year, and the not-very-glossy and slightly-patchy upperparts might also fit a 1st-year better.

 

[birdmeister]

I'm fairly sure it's either a White-faced or Glossy x White-faced, but I don't think it's wise to discount a hybrid quickly from these photos.

It's my understanding that hybrids regularly show red eyes (pure Glossy does not, which has been mentioned above). The thing that gives me pause in the OP's good images is what looks like bluish/whitish borders to reddish facial skin. However, I have no personal experience with White-faced or hybrids and would like to hear other opinions.

Here are eBird checklists with photos of hybrids. At least one (probably both) of these observers is very highly experienced and a sharp birder. The second checklist is a bit less applicable since the bird is in breeding plumage, but still shows the hybrid face pattern.

https://ebird.org/checklist/S76430177

https://ebird.org/checklist/S68000665

 

[Butty]

fairly sure it's either a White-faced or Glossy x White-faced

But... why suspect a hybrid when a) white-faced ibis (apparently) fits just fine and b) glossy ibis is (apparently) excluded by iris colour?

 

[birdmeister]

But... why suspect a hybrid when a) white-faced ibis (apparently) fits just fine and b) glossy ibis is (apparently) excluded by iris colour?

Several features make me think this bird doesn't fit a pure bird of either species:

1. Dirty grayish-red facial skin, not as red as I think is typical for White-faced
2. Thin, defined pale lines bordering facial skin, a Glossy feature that pure White-faced should not show
3. Red eyes that pure Glossy doesn't show

In short, I just don't think the bird looks right for a normal White-faced.

 

[njlarsen]

I would add that the reddish facial skin should not usually be seen on a glossy in winter plumage according to my Sibley. I don't have enough experience to talk about a hybrid.

Niels

 

[Deb Burhinus]

Definitely not. They might do, but in birds in general such a link is absolutely not to be expected/assumed.
My understanding is that white-faced ibis has a red(dish) iris at all ages.

Afaiwa - juvenile WFI have brown irises turning to brownish reddish in imm. The reddish tones on the coverts and scaps rule out a juvenile WFI imo (which are overall greenish)

However - It looks like an adult White-faced Ibis in non-breeding plumage to me - the facial skin is not so red in non-breeding plumage and the white border can be present to some degree in both species

ML315682851 - White-faced Ibis - Macaulay Library

Macaulay Library ML315682851; © Robert Lewis; Orange, California, United States

macaulaylibrary.org

 

[Butty]

1. Dirty grayish-red facial skin, not as red as I think is typical for White-faced
2. Thin, defined pale lines bordering facial skin, a Glossy feature that pure White-faced should not show

1. Sibley shows 1st-winter white-faced ibis as having entirely grey facial skin.
2. Thin pale lines bordering the facial skin is (I've always thought) a well-known feature of immature/non-breeding white-faced ibis, and is shown by Sibley.
So it still (apparently) seems good for full-blooded white-faced ibis.

The reddish tones on the coverts and scaps rule out a juvenile WFI imo (which are overall greenish)

In mid-November, if it's a young bird, it would of course be 1st-winter rather than juvenile. Sibley says, about 1st-winter white-faced ibis: 'averages paler golden-rosy gloss' (presumably relative to adult, either breeding or non-breeding) - which makes it sound as though the rosy/red/whatever tone is variable, i.e. there can be some in 1st-winter birds - in which case 1st-winter wouldn't be ruled out. And, as I indicated above, the patchiness of the upperparts may indicate some retained juvenile feathers which, if so, would make it 1st-winter.

 

[Deb Burhinus]

1st-winter wouldn't be ruled out. And, as I indicated above, the patchiness of the upperparts may indicate some retained juvenile feathers which, if so, would make it 1st-winter.

Afaia - as I indicated above, juvenile irises are brown - imm. irises are also brown (with a pinkish tinge later but in early first winter still brown albeit lighter/warmer - see link below). A few individuals can have reddish eyes by December. Both the OPs have bright red eyes however, so while not ruling out advanced 1w, it doesn’t seem as likely.

The ‘patchy’ scaps and coverts look fine for a sub-adult/adult to me - the moult of Ibis species is afaik, quite complex (a bit like Cormorants) and moult continues at several different loci through the winter with an additional pre-breeding moult so I would expect there to be continuing signs of active moult and several generations of feathers visible as in the OP. Post-juveniles in White-faced (If the strategy is similar to Glossy) afaiu, would not have a complete post-juvenile moult, and still look predominantly dark greenish in their first winter imo (at least early on). Also note the primaries look very dark and quite fresh compared to the 1w in the link below - 1st winter White-face also have a pale cheek patch which is absent in both the OPs.

Some good background ID notes and images of a typical 1st Winter November, White-faced Ibis here
http://www.jeaniron.ca/2019/wfibis.htm.

• note the rust brown irises
• greenish plumage (lacking the rusty scaps
• pale cheek patch
• worn/faded primaries

Also compare a 1w Glossy Ibis (29th November further down the page on the above link and note how dark that individual is still too)


Imo, the OP birds are at least 2cy/3cy birds (or even adults in non-breeding plumage) as here

White-faced Ibis Photos and Videos for, All About Birds, Cornell Lab of Ornithology

<p>The handsome White-faced Ibis shimmers with purple, green, and bronze plumage. Breeding adults add to this a ruby-red eye surrounded by a sharp white mask, and pink legs. Flocks of this long-legged bird forage in marshes across large parts of the American West, where wetlands are very scarce...

www.allaboutbirds.org

but it would be helpful to get some more detailed references to moult strategy in WfIbis to age them accurately.

Regardless of age, I think the OPs are almost certainly White-faced - the key criteria here being the diagnostic red irises which don’t show in Glossy Ibis in any age.