Egret at Ras al Khor Wildlife Sanctuary, Dubai- December 2018 (1 Viewer)

Aladdin · Dec 16, 2018

Dear Members and Bird watchers

How to see the difference between a young and old Great Egret? For how long time do a Great Egret grow to be a "GREAT" Egret?

Picture #1 We see a Common Greenshank, but look at the size difference between the two Great Egrets. And I have no doubt that the "LITTLE" Egret is a Great Egret, gape extends between the eye and it looks exactly the same as the big Egret in colours etc. Is this a young Great Egret?

Picture #2 A Great Egret and a smaller Egret. Great difference in size. IN picture # 3 and 4 we can see the smaller Egret, yellow bill and yellow gape extending just behind the eyes.

I think that they have only spotted one Intermediate Egret in Dubai. And I was thinking Cattle Egret even though it is not walking around in the pastures. I have seen them fishing before and I have thought it was a Little Egret before I realized that the bill was yellow.

But this small Egret is too big to be a Cattle Egret. And the hunting style, leaning forward with extended neck as the Intermediate Egret. Yellow bill and Iores. Gape extending just a notch behind the eye, so it should not be a Intermediate.

And might be my imagination, the head is more round than the Great Egret, comparing with picture #5.

Any Ideas about the identity of the bird in picture #2 and 3? Is it a small Great Egret?

Kind regards and happy birding
Aladdin

MacNara · Dec 16, 2018

Hi Alladin,

Birds are full-sized when fledged, so the size difference is not related to age (though there is some individual difference in size, of course).

And part of the difference in your photo is the posture of the birds - the front one crouched down with its neck folded in, and the other extended as far as possible.

However, if you look, you will see that the bigger bird has a yellow tibia (upper leg), while the smaller bird has a blue upper leg.

There are two recognised sub-species of Egretta alba - E.a. alba and E.a. modesta, and this leg colour difference (actually yellow for alba and black in winter for modesta where I live) is one of the distinctive features, and a variation in size is another. Both of these sub-species can be seen in autumn, winter and spring near my house in central Japan. Modesta breeds not far away, I think alba breeds only on the continent (but I'm not sure).

In Japanese, alba is 'Big Great Egret' and modesta is 'Intermediate Great Egret' ('Intermediate Egret is, of course, a different bird).

It's not easy to get a comparison picture of them together (in the same frame), but one of each was in the same small pond at my local spot last year, and I attach a few photos.

The pond is a shallow and even, so the depth of water each bird is standing in is the same.

In the first two pictures - standing and with modesta flying, you can see there is a definite size difference. You should also be able to see that the larger bird has yellow tibia, while the smaller bird has black tibia. It's definitely my impression that the trousers (feathering at the top of the tibia) is proportionately longer in modesta, but I think alba has longer legs which may contribute to this effect. If you look at the standing photos (photo 1 and photo 4) you can see the yellow of the tibia of alba, but only the trousers of modesta.

Photo 3 is enhanced a little to show the yellow tibia more clearly (you can see the black tibia of modesta clearly in photo 2).

I include photo 4 for balance. Here you can see that if both birds are in a similar stretched posture, the size difference doesn't seem so large. But it is still clearly there, and notice that the alba bird's tail is out of the water and the tibia visible, while the opposite is true of the modesta.

Some people think these will eventually be two species. Apart from the size and bare parts colouration difference, one reason for agreeing from my personal experience is that I have seen a group of modesta (much commoner here in Japan in the winter) mob a couple of alba. And the flight photos in the photos I attach were of the birds harassing each other. So it seems they recognise themselves as 'different'.

I hope this helps. I'm not an expert, just reporting some personal observations. These birds are very widespread in the world, and there is surely more differentiation than I am aware of which may be relevant to your question.

Anyway, I think your photos show an alba and modesta together.

Aladdin · Dec 16, 2018

MacNara said:
Hi Alladin,

Birds are full-sized when fledged, so the size difference is not related to age (though there is some individual difference in size, of course).

And part of the difference in your photo is the posture of the birds - the front one crouched down with its neck folded in, and the other extended as far as possible.

However, if you look, you will see that the bigger bird has a yellow tibia (upper leg), while the smaller bird has a blue upper leg.

There are two recognised sub-species of Egretta alba - E.a. alba and E.a. modesta, and this leg colour difference (actually yellow for alba and black in winter for modesta where I live) is one of the distinctive features, and a variation in size is another. Both of these sub-species can be seen in autumn, winter and spring near my house in central Japan. Modesta breeds not far away, I think alba breeds only on the continent (but I'm not sure).

In Japanese, alba is 'Big Great Egret' and modesta is 'Intermediate Great Egret' ('Intermediate Egret is, of course, a different bird).

It's not easy to get a comparison picture of them together (in the same frame), but one of each was in the same small pond at my local spot last year, and I attach a few photos.

The pond is a shallow and even, so the depth of water each bird is standing in is the same.

In the first two pictures - standing and with modesta flying, you can see there is a definite size difference. You should also be able to see that the larger bird has yellow tibia, while the smaller bird has black tibia. It's definitely my impression that the trousers (feathering at the top of the tibia) is proportionately longer in modesta, but I think alba has longer legs which may contribute to this effect. If you look at the standing photos (photo 1 and photo 4) you can see the yellow of the tibia of alba, but only the trousers of modesta.

Photo 3 is enhanced a little to show the yellow tibia more clearly (you can see the black tibia of modesta clearly in photo 2).

I include photo 4 for balance. Here you can see that if both birds are in a similar stretched posture, the size difference doesn't seem so large. But it is still clearly there, and notice that the alba bird's tail is out of the water and the tibia visible, while the opposite is true of the modesta.

Some people think these will eventually be two species. Apart from the size and bare parts colouration difference, one reason for agreeing from my personal experience is that I have seen a group of modesta (much commoner here in Japan in the winter) mob a couple of alba. And the flight photos in the photos I attach were of the birds harassing each other. So it seems they recognise themselves as 'different'.

I hope this helps. I'm not an expert, just reporting some personal observations. These birds are very widespread in the world, and there is surely more differentiation than I am aware of which may be relevant to your question.

Anyway, I think your photos show an alba and modesta together.

WOW! CHEERS! Very interesting!

Now I will start to look between the differences between the different subspecies and according to Wikipedia there is 4 different Subspecies.

So I learned from you :
Picture #1 is a E.a. alba (Yellow legs)
Picture #2 is a E.a. modesta (Blue/ black legs)

Thank you for that! And I add a third picture, according to Wikipedia is found in India, the A. a. modesta Gray and I took the picture in Sundarbans in India when I was there to look for tigers.

The legs are fully black on the Indian bird.

Anyway, I was lucky to get both off the Great Egrets in the same picture and it was really striking, the size difference. And they didn´t seemed to be unfriendly with each other.

But I saw the Western reef Heron, both white and dark morph in the pond, staying well clear of each other. I meet another birder and he showed me some pictures he had been taken a few days earlier. And the white and dark morph had come a little too close to each others and they had started to fight, big time!

Thank you again, highly appreciated
Best regards and happy birding
Aladdin

MacNara · Dec 16, 2018

I'm sure that someone who knows more than me will come along and make a comment, which will advance the thread.

But my own experience in my very limited area of the world and since I started paying some attention to the difference between these two sub-species leads me to the opinion that alba and modesta are probably worth splitting. They overlap a lot, so I'd be interested to hear if people think they interbreed.

Phil Andrews · Dec 16, 2018

https://www.hbw.com/species/great-white-egret-ardea-alba

johnallcock · Dec 16, 2018

I agree that the first photo shows two Great Egrets, and that the size difference between these two as well as the difference in leg colour suggest that they are alba and modesta.

The smaller bird in the second photo and in photos 3 & 4 is an Intermediate Egret. Compared to Great Egret, notice the different neck shape (broad at base, tapering to narrower near head), shorter bill, dark tip to bill and plumes on the breast. The posture is also typical of Intermediate.

Aladdin · Dec 16, 2018

johnallcock said:
I agree that the first photo shows two Great Egrets, and that the size difference between these two as well as the difference in leg colour suggest that they are alba and modesta.

The smaller bird in the second photo and in photos 3 & 4 is an Intermediate Egret. Compared to Great Egret, notice the different neck shape (broad at base, tapering to narrower near head), shorter bill, dark tip to bill and plumes on the breast. The posture is also typical of Intermediate.

Thank you all!

Yes, the two Egrets on the first picture was clear to me, just wondering about the different sizes and as MacNara tought me, they are different Subspieces. And for me this was very interesting as it never would have thought about that, thanks! Learn something new everyday!

As johnallcock kindly point out, the shapes of the other small Egret reminds me about the Intermediate Egret. Yellow Iora and a yellow gape. And the hunting technique, tends to stalk upright with neck extended forward.

I have seen them hunting looking like a Great Egret as well.

Picture 1+2+3 in this post is the same bird as on picture 3 and 4 in the first post. We can see that the yellow gape extends just a notch behind the eye and the "kink" on the neck, this put me off the Intermediate egret and the fact that they have only observed one Intermediate in Dubai before.

Picture #4 is the same bird walking just in front of a Great Egret. And, might be my imagination, but the smaller Egret´s head looks more "round" than the Great Egrets pointy shaped head

Last picture is an Intermediate Egret that I spotted along the Hiran River - Sasan Gir, India

Kind regards and happy birding
Aladdin

MJB · Dec 16, 2018

MacNara said:
But my own experience in my very limited area of the world and since I started paying some attention to the difference between these two sub-species leads me to the opinion that alba and modesta are probably worth splitting. They overlap a lot, so I'd be interested to hear if people think they interbreed.

IOC1.6 supported a split, but IOC2.10 reversed this decision until the relationship between American Great Egret A.a. egretta and all the other alba taxa can be determined, following the limited data available: see Pratt 2011.
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

MacNara · Dec 16, 2018

johnallcock said:
The smaller bird in the second photo and in photos 3 & 4 is an Intermediate Egret. Compared to Great Egret, notice the different neck shape (broad at base, tapering to narrower near head), shorter bill, dark tip to bill and plumes on the breast. The posture is also typical of Intermediate.

Thanks for that John. Indeed, when I wrote the first version of my original long post, I included a sentence saying that I was basically commenting only on the first photo. I deleted it because on re-reading Alladin's post, I took at face value his claim that Intermediate Egret has only been seen once in Dubai, without actually looking at the photos closely, and after the half-hour it took to compose my post, I neglected to go back and look at the others.

(Indeed, on re-reading now, I realise that I misunderstood Alladin's post (my fault, the post is clear enough) to say he was sure that all were Great and that he wanted to know about the size difference, rather than noticing the subsidiary question he raised about photos 2 and 3 and so looking properly at those photos.)

Apologies for my sloppiness and thanks for picking up on it.

If 2, 3 and 4 show Intermediate Egrets, then presumably he should send his shots to the Dubai rarities committee, for the Intermediate Egret, rather than the Great Egrets!

Aladdin · Dec 16, 2018

MacNara said:
Thanks for that John. Indeed, when I wrote the first version of my original long post, I included a sentence saying that I was basically commenting only on the first photo. I deleted it because on re-reading Alladin's post, I took at face value his claim that Intermediate Egret has only been seen once in Dubai, without actually looking at the photos closely, and after the half-hour it took to compose my post, I neglected to go back and look at the others.

(Indeed, on re-reading now, I realise that I misunderstood Alladin's post (my fault, the post is clear enough) to say he was sure that all were Great and that he wanted to know about the size difference, rather than noticing the subsidiary question he raised about photos 2 and 3 and so looking properly at those photos.)

Apologies for my sloppiness and thanks for picking up on it.

If 2, 3 and 4 show Intermediate Egrets, then presumably he should send his shots to the Dubai rarities committee, for the Intermediate Egret, rather than the Great Egrets!

MacNara!

Your post was excellent and I learned a lot. Your "sloppiness" is most likely due to my English and I sometimes get confused myself when I´m writing as English is not my native language.

Thank you all, I have learned a lot from this posts, highly appreciated.

Kind regards and happy birding. And I take this opportunity to wish you all a happy X-mas

Aladdin

Egret at Ras al Khor Wildlife Sanctuary, Dubai- December 2018 (1 Viewer)

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