Field Identification

little egret_Guryongpo_Nov15c_RS_NM

How Well Do We Know Nominate Little Egret Egretta garzetta?

Nial Moores, November 16th 2015.

On November 15th, I birded Guryongpo with Jason Loghry, Ha Jeong Mun and Seo Hae-Min. Driving through Gyeongju, from the moving car we saw a flock of perhaps 40 Little Egret Egretta garzetta leaving their roost (a decent-sized flock for the time of year, as the species is much commoner here in summer than winter); and then during a brief stop, we saw a few more feeding on the river in Pohang (none of which we looked at closely: how many birders do?). We then had good views of one feeding on the beach, sometimes angle-necked like a Chinese Egret as it waded or walked along the surf-edge. In good light (and in near-windless conditions), this bird seemed to me to show several features that might well be usual in Little Egrets in this region but which nonetheless seem to contradict expectations and descriptions of nominate garzetta in some of the popular birding literature.


Little egret_guryongpo_nov15b_RS_NM


little egret_Guryongpo_Nov15c_RS_NMLittle Egret Egretta garzetta, Guryongpo Peninsula, November 15 © Nial Moores

 As can be seen in the images, the bird has clean yellow lores; extensive pink along the lower mandible that peters out fairly gradually; all dark legs, with dark extending patchily onto the upperside of one of the toes; a shaggy-looking nape and hindnape, unrelated to wind (and lacking any trace of the two lanceolate nuchal plumes distinctive of the species in most adults); full breast plumes; and extensive aigrettes which extend slightly past the closed wings and tail.

First then, how to age this bird?

It is too well-plumed for a juvenile type. It is therefore a First-winter or an adult.

The online account of Little Egret posted by the Heron Conservation Group of the IUCN SSC, states that in the non-breeding plumage of adults “short plumes may occur on back and chest”. These plumes do not look short.

They add:

“When breeding, the Little Egret develops characteristic plumes on the back of the head, lower throat, and back. Particularly distinctive are the two or three thin, lanceolate crown plumes, which can be up to 16 cm long. The elongated feathers at the base of the neck are lanceolate distally. Lax back plumes are long, exuberant, and slightly recurved, but do not extend beyond the tail.”

According to Sibley online, when looking to find a Little Egret among Snowy Egrets in North America, the best feature is the two or three long nuchal plumes which “are present year-round on adults, except when missing during molt sometime between August to November”.

This bird then seems most likely to be an adult in non-breeding plumage with perhaps slightly delayed moult (hence the lack of these nuchal plumes). If so, then why are the other plumes on the breast and upperparts already so well-developed?  Moreover, in the Guryongpo bird the dorsal plumes even look to extend a little beyond the tail, as they do much more obviously in image 392 in the Birds Korea Gallery, a Little Egret photographed in the ROK in June 2008 by Tim Edelsten.

Like the Guryongpo bird, the lores of the breeding-plumaged bird in image 392 are yellow. The subspecies we have is supposed to be nominate garzetta. How usual or unusual are yellow lores supposed to be in nominate Little Egret?

The excellent Collins Bird Guide covering the birds of Britain and Europe states that the lores of European nominate garzetta are “blue-grey for greater part of the year, reddish during courtship period”; Brazil’s field-guide covering East Asia states that they are “yellow to greyish-green (non-breeding)”; and the Heron Conservation Group state that in the northern Australian subspecies of Little Egret E.g. immaculata, which is not suspected to occur in East Asia, “Nonbreeding lores are yellow, an important distinction from garzetta. Legs and feet are black, with yellow soles.”

So, while East Asian Little Egrets are of the nominate subspecies, and the nominate subspecies does not show yellow lores, East Asian Little Egrets can have yellow lores in the breeding season (but perhaps not in the non-breeding season?)…

The bill pattern of this Guryongpo bird also seems a little unusual: the extensive pale pink on the lower mandible seems more like that shown by most First-winters than by adults.  The Collins Bird Guide states that the bill of Little Egret is black. However, the plate in the same guide shows a breeding-plumaged adult with extensive pale (grey-pink?) along the bill base. There is no clear drawing of a non-breeding adult; and the image of the immature bird is too small to make out much detail beyond greenish legs (something that is shown by juvenile Little Egrets, in which legs darken quite rapidly in East Asia , however). The much less convincing (and quite sinister-looking!) plate in Brazil’s field guide shows an adult winter Little Egret with an all dark bill, and very few plumes, and states that the bill is black, and, puzzlingly, that young have “yellowish lower mandible” (this is a colour I do not remember seeing in any Little Egret anywhere, whatever their age: has anyone else?).

Of some interest too, an online image of a breeding plumage immaculata Little Egret from Northern Australia shows full plumes, yellow lores and extensive pink along the lower mandible.

The Guryongpo bird of November 15th instantly brought to mind a Little Egret that I digiscoped there in late January 2005 (in pre-Swarovski days: see below), and of yellow-lored Little Egrets I have seen there several times in subsequent winters. The 2005 bird was more obviously in breeding plumage, but had only one elongated nuchal plume and this was much shorter than those of most adult Little Egret (please note that in the image, this fairly short plume casts a misleadingly long shadow!). It also had an oddly shaggy head and nape (suggesting Snowy Egret) and really rather bright yellow lores.

RS-lateJan2005_LittleEgret_Guryongpo_NMLittle Egret, Guryongpo Peninsula, January 2005 © Nial Moores

In turn, both of these birds also reminded me of some correspondence I had last year with Angus Lamont, an obviously-experienced birder who lives in Shanghai. AL is very familiar with Little Egret. He wrote to say that he had found perhaps five pairs of birds that showed features that were not typical of Little Egret nesting in among a colony that contained 40 pairs of ordinary-looking Little Egrets. He suspected that these birds were Chinese Egret while admitting that he was “confused as all the breeding birds show a black upper mandible while the lower mandible is also black (although some birds show some traces of yellow). According to literature breeding birds should have yellow bills. In all other respects the birds are in normal breeding plumage. Have you come across birds like this at the Korean breeding sites? Do you think that the acquisition of a yellow bill might be age related?” (Angus Lamont, in lit., July 3rd 2014).

He sent me some images asking for opinions on their identity.

I have never seen dark-billed breeding-plumaged Chinese Egret and I very much doubt that such birds occur, as even non-breeding birds (seen e.g. in Korea and Vietnam and other parts of South-east Asia in winter) show quite extensive orange on the lower mandible. The images below are how Chinese Egret look to me here in Korea (and in other places I have seen them):


juvchineseegret_nakdong-aug2005-RS-NMChinese Egret Egretta eulophotes: Above, adult, Baekryeong, May 2015; below non-breeding adult or First Calendar-year , Nakdong Estuary, August 2005 © Nial Moores

On July 6th 2014 I replied to AL, stating that, “I regret to say that I am confident that some of the images are of Little Egret – including the two labelled as adult and a young in the fish pond. One other image shows what looks to be an adult Chinese near the nest (called young in your images).  Perhaps you saw Chinese nesting in close proximity with a Little or something even more unexpected…” before adding further details on some of the other differences between Chinese and Little Egrets. These include a different structure (especially longer-looking tibia and tarsus in Little) and differences in bare part coloration.  I wrote too that in Chinese Egret,  “Post-breeding adults and juveniles have green legs with poorly contrasting yellow feet (with adults often showing some black – at least on the shins); and bills that are dark, apart from a basal third or half (though I had intended to write “two-thirds or half of the lower mandible”) which is sharply demarcated off from the black -without the soft-edged and gradual fade of Little. This distinctive bare part coloration (at least, distinctive from Little) is maintained through until January at least. By February or March birds start to move back into breeding plumage.”

However (to my genuine surprise), AL then published the records of all of these birds as Chinese Egret (BirdingAsia volumes 22 and 23), even crediting my input! An image (plate 2, Vol 2: 89) of what AL labelled as a “mystery egret by the nest” taken on May 26th 2014 has to my eyes much more the structure expected of Little Egret; no lanceolate nuchal plumes but extensive plumes on the breast and fairly extensive dorsal plumes perhaps extending past the tail; and what look to be yellowish lores. Plate 6 on page 90 of Volume 2 also shows a bird that also does not sit at all well with my own experience of juvenile Chinese Egret either (see above), instead looking much closer to a Little Egret, albeit with a rather shaggy head and nape (but perhaps the start of a longer nuchal plume?). It also seems to have  much longer-looking tibia than the two birds in Plate 3, labelled as Chinese Egret fledglings at the nest.

Again, according to the Heron Working Group, the Little Egret is “highly variable” in appearance and also has distinct coastal and inland populations and several subspecies. Are the two birds at Guryongpo and some of those photographed in Shanghai odd-looking Little Egrets that are still within the range of individual variation of nominate garzetta? Do some of them perhaps have some hybrid influence? Or could some of them (and many other East Asian Little Egret) instead belong to a different taxon?

One thing is sure: these kinds of birds make clear (yet again!) that there is still so much to be learned, whether the species is common or not!

Please let us know your thoughts. If the comment option on the blog does not work (seems often not to), then please send me a mail instead  to: nial.moores at birdskorea dot org.




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