Great or Intermediate Egret? (Singapore) (1 Viewer)

[lowressgbirding]

Hi everyone!

I've been googling quite a bit on how to differentiate between the Great and Intermediate Egret, but I'm still quite stumped looking through my photos.

I have 4 sets of photos here (different birds, although bird 2 might be the same as bird 3 or 4). The gape doesn't seem to extend far behind the eye, but the neck and beak look pretty long on all these birds.

Would appreciate any tips on how to identify whether these are Great or Intermediate Egrets or a mix of both, and why.

Thanks!

 

[Andy Adcock]

Intermediate, as you say, gape line doesn't extend beyond the rear of the eye but I think the last bird 4 images are Great. No books to hand but I think, the dark tip to the bill is also a feature of Great.

 

[lowressgbirding]

Intermediate, as you say, gape line doesn't extend beyond the rear of the eye but I think the last bird 4 images are Great. No books to hand but I think, the dark tip to the bill is also a feature of Great.

Thanks!

I believe the dark tip might be a feature of the Intermediate actually. Perhaps all these birds are Intermediate then. The kinks in the neck also do not look as obvious as the Great's, from pictures that I can find online.

 

[THE_FERN]

Intermediate, as you say, gape line doesn't extend beyond the rear of the eye but I think the last bird 4 images are Great. No books to hand but I think, the dark tip to the bill is also a feature of Great.

Well... ...difficult. But stubby bill and [appearing] plumpish-body + not super-long neck might favour intermediate. It gets my vote.

 

[Larry Sweetland]

This is why I like the concept of Indeterminate Egret 😁

 

[HouseCrow]

I would agree with Andy, all but 4 Intermediate; relatively short bill, big-ish head.
Bird 4 is not always obvious but the last one seems to show a proportionally small head.
Good name for Larry's suggested bird would be Egretta Ardea indeterminata.

my 2p

cheers
G

 

[Butty]

I think, the dark tip to the bill is also a feature of Great

Muck?

 

[lowressgbirding]

Thanks everyone for sharing your insight! "Indeterminate Egret" cracked me up 😄

 

[MacNara]

I think they are all Intermediate. The dark tip to the bill is if anything a feature of Intermediate. But I fully agree that all (except 2) are on the borderline for which of the two species it is, even if you've seen them often (the long, curved necks). The gape line to the rear can be hidden sometimes, either by feathers or the light, but in these birds I think not. I disagee with Andy and think that #4 is a clear Intermediate.

 

[HouseCrow]

B*gger, I think you are right Mac, 4 too is most likely an Intermediate.
I compared the last photo of 4 to one of my Eastern Great Egret last year

Great Egret (Ardea alba)

Great Egret from 1 Hamarikyuteien, Chuo City, Tokyo 104-0046, Japan on March 6, 2020 at 02:43 PM by Gerben ter Haar. not interested at all in human imposters

www.inaturalist.org

The head is really small relative to the bill, the eye small in the head.
Intermediate is more well proportioned I think.

pardon the switching to and fro
cheers,
G

 

[johnallcock]

I agree they're all Intermediate. The shaggy front to the foreneck (most visible here on 2c and 4d) is a feature I find useful that doesn't get mentioned as much as I think it deserves

 

[lowressgbirding]

Thanks everyone and hello again!

So I managed to finally spot a great egret today and thought to share some photos for comparison. The bird was a bit further today so the photos aren't so good, but the distinguishing features can be seen quite clearly, i.e. the long gape line extending beyond the eye, the kink in the neck, the fully yellow bill and how it's feeding in water instead of on the grassland.

Cheers!

 

[MacNara]

Yes, no problem with Great Egret here.

As you may know, Great Egret is divided into two subspecies - alba (larger than Grey Heron) and modesta (smaller than Grey Heron). We have both in Winter where I am in central Japan (Nara, Osaka, Kyoto), but only modesta (year-round), and not alba, breeds near here (so far as I know). I try not to be obsessive, but I think that these should be two species - they sometimes disagree and fight each other for example. However, so far, the 'authorities' don't agree with me.

I think there are other differences apart from overall size between alba and modesta - in winter the upper leg (tibia) is blue-ish on modesta (the most common) and it is yellow or yellow-ish in alba. And in addition, though I don't see it mentioned elsewhere, I think that the 'pants', or 'socks', or whatever you want to call the feathering that reaches from the body down the top of the tibia, is longer and more obvious on modesta than on alba (and indeed the legs are slimmer overall on modesta). (I think this is a neglected feature, rather like the 'shaggy front to the foreneck' which John Allcock mentions for Intermediate Egret in post#11.)

Your bird is clearly modesta, as I will try to demonstrate by posting a crop of one of your photos and a few photos showing the modesta and alba sub-species together that I took a couple of days ago near my house in Nara, Japan.

I hope this helps (you and anyone else who is still looking). The more I look, the more I am convinced these are two different species.

Photo one is the OP's bird, (cropped) - notice the blue and the long 'pants'
Photo two shows my two birds together - look at the size difference (a little extreme even for these two sub-species, actually)
Photo three show my two birds, and you can see from the gape lines on each face that both are 'Great Egret' (we definitely do not have wintering Intermediate here in my area, though I'm not sure about southern Japan, although they breed here)
Photo four shows my two birds and I hope you can clearly see the difference in leg colouration among other details

 

[lowressgbirding]

Thanks for sharing, MacNara! Indeed, the bird I saw today was smaller than I expected.

It's very interesting how the modesta and alba can be so different! Do you know what the range of the alba is and would I be able to find it in Singapore?

Edit: just found this on wikipedia; it seems I won't be able to see the alba in Singapore. This makes it harder for us to differentiate between the Intermediate and the Great, which may have quite similar sizes here, if we don't get good enough photos to see the finer details like gape line etc.

• A. a. alba Linnaeus, 1758 – nominate, found in Europe and across the Palearctic.
• A. a. egretta Gmelin, JF, 1789 – found in the Americas
• A. a. melanorhynchos Wagler, 1827 – found in Africa
• A. a. modesta Gray, JE, 1831 – eastern great egret, found in India, Southeast Asia, East Asia and Oceania

 

[MJB]

Yes, no problem with Great Egret here, G.

As you may know, Great Egret is divided into two subspecies - alba (larger than Grey Heron) and modesta (smaller than Grey Heron). We have both in Winter where I am in central Japan (Nara, Osaka, Kyoto), but only modesta (year-round), and not alba, breeds near here (so far as I know). I try not to be obsessive, but I think that these should be two species - they sometimes disagree and fight each other for example. However, so far, the 'authorities' don't agree with me.

I think there are other differences apart from overall size between alba and modesta - in winter the upper leg (tibia) is blue-ish on modesta (the most common) and it is yellow or yellow-ish in alba. And in addition, though I don't see it mentioned elsewhere, I think that the 'pants', or 'socks', or whatever you want to call the feathering that reaches from the body down the top of the tibia, is longer and more obvious on modesta than on alba (and indeed the legs are slimmer overall on modesta). (I think this is a neglected feature, rather like the 'shaggy front to the foreneck' which John Allcock mentions for Intermediate Egret in post#11.)

Your bird is clearly modesta, as I will try to demonstrate by posting a crop of one of your photos and a few photos showing the modesta and alba sub-species together that I took a couple of days ago near my house in Nara, Japan.

I hope this helps (you, G, and anyone else who is still looking). The more I look, the more I am convinced these are two different species.

Photo one is your bird, G (cropped) - notice the blue and the long 'pants'
Photo two shows my two birds together - look at the size difference (a little extreme even for these two sub-species, actually)
Photo three show my two birds, and you can see from the gape lines on each face that both are 'Great Egret' (we definitely do not have wintering Intermediate here in my area, though I'm not sure about southern Japan, although they breed here)
Photo four shows my two birds and I hope you can clearly see the difference in leg colouration among other details


View attachment 1419307View attachment 1419308View attachment 1419311View attachment 1419312

One of the reasons that there has been no decision on whether modesta should be split from alba is that the relationships between them and egretta of the Americas have not been fully established; the species limits of 'American Great Egret' need to be determined, too. These circumstances are laid out in Pratt 2011, but it seems that funding has gone to other priorities. Another aspect is that although the American Ornithologists' Union 6th edition (incl. 40th supplement) mandated the change of genus for the American populations from Casmerodius to Ardea, it may still be a bone of contention to some.
MJB
Pratt, HD. 2011. Observations on species limits in the Great Egret (Ardea alba) complex. J. Heron Biol. & Conserv. 1: 5. www.HeronConservation.org/vol1/art5

 

[MJB]

Thanks for sharing, MacNara! Indeed, the bird I saw today was smaller than I expected.

It's very interesting how the modesta and alba can be so different! Do you know what the range of the alba is and would I be able to find it in Singapore?

Edit: just found this on wikipedia; it seems I won't be able to see the alba in Singapore. This makes it harder for us to differentiate between the Intermediate and the Great, which may have quite similar sizes here, if we don't get good enough photos to see the finer details like gape line etc.

• A. a. alba Linnaeus, 1758 – nominate, found in Europe and across the Palearctic.
• A. a. egretta Gmelin, JF, 1789 – found in the Americas
• A. a. melanorhynchos Wagler, 1827 – found in Africa
• A. a. modesta Gray, JE, 1831 – eastern great egret, found in India, Southeast Asia, East Asia and Oceania

I suggest that you are being too pessimistic about alba appearing in Singapore. The BirdLife Datazone map for Great Egret (http://datazone.birdlife.org/species/factsheet/great-white-egret-ardea-alba/distribution) can be interpreted (via the Wikipedia data, but also the slightly more detailed data in IOC 11.2 Master List) to show that the northernmost summer breeding distribution of alba 'across the Palearctic' should result at least in vagrancy to southern Asia. The resident population of southern Asia is certainly modesta, and the southernmost migrant population 'across the Palearctic' (at the latitude of Afghanistan) is probably mostly modesta.
MJB

 

[MacNara]

Hi MJB: Thanks for your very useful contributions. Your profile says you are from Holt. Is that Holt in Norfolk, England, or is it one of the other Holts around the world?

 

[johnallcock]

I suggest that you are being too pessimistic about alba appearing in Singapore. The BirdLife Datazone map for Great Egret (http://datazone.birdlife.org/species/factsheet/great-white-egret-ardea-alba/distribution) can be interpreted (via the Wikipedia data, but also the slightly more detailed data in IOC 11.2 Master List) to show that the northernmost summer breeding distribution of alba 'across the Palearctic' should result at least in vagrancy to southern Asia. The resident population of southern Asia is certainly modesta, and the southernmost migrant population 'across the Palearctic' (at the latitude of Afghanistan) is probably mostly modesta.
MJB

It's plausible that alba could turn up as a vagrant in Singapore, but I think it would be extremely rare. I think the South Asia listing in IOC refers to birds in India/Pakistan/Bangladesh (?). In Eastern Asia it seems to rarely get much further south than central China/southern Japan (eg only one confirmed record in Hong Kong). eBird shows one record of alba in all of southeast Asia - an uncounted list in Thailand, with no details on how the subspecies was identified.
Singapore lies about 2,500km outside the normal range of this subspecies in south and east Asia. There are records of vagrant herons further out of range than this so it's not impossible, but it is fairly unlikely.

 

[MJB]

Hi MJB: Thanks for your very useful contributions. Your profile says you are from Holt. Is that Holt in Norfolk, England, or is it one of the other Holts around the world?

Norfolk
MJB

 

[MacNara]

Norfolk
MJB

A great birding base! I grew up in Birmingham, England, but my great friends in England are in Bury, Suffolk and that area. I only started birding about fifteen years ago in Japan where I have lived for forty years - hence the Japanese flag, because it's the area I know, though I have been lucky enough to get to know some bits of Africa and other continents (not the Americas) in the last decade. The last time I was in England, about ten years ago, I had a spare five days and did some birding along the Norfolk coast - Titchwell, Cley, Minsmere, Snape, and the other main places, which is my total English birding experience. That's why I wondered if your 'Holt' was there.