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Thursday, August 24, 2006

Possible Western Reef-Heron, cont'd.





Next three photos show a variety of feeding behaviors.



Here are more photos of the interesting heron that is being seen in NH and ME. The heron was discovered in Kittery Point, ME on Friday, 8/18/06. On the afternoon of Saturday, 8/19/06, it was seen near Newcastle, NH. It then alternated for the next several days, between ME in the morning and NH in the afternoon. It was still being seen today in NH on Rt. 1B, in New Castle.
The reason we are saying it is a possible Western Reef-Heron (sometimes called Western Reef Egret), is that there are some differences in the current resources as to the identification of this species and we wanted to take time to further explore the current state of thinking on the possible classification of this bird.
When we first saw the bird, we, and other birders with us, were having trouble reconciling the dark bill, dark lores, and black legs with fairly bright yellow feet with the pictures in field guides that birders had present at the site (these included: Birds of East Africa and the new National Geographic Complete Birds of NA). Most other field guides to North American birds do not include Western Reef Heron. When we got home, we continued to reference other guides and here is a summary of what we discovered.

What current field guides say about Western Reef-Heron

boea=Birds of East Africa by Stevenson and Fanshawe, pub. 2002
boem= Birds of Europe by Killian Millarney, pub. 1999
boej= Birds of Europe by Lars Jonsson, pub. 1993
ng= the newest Nat. Geo. Complete Birds of NA ed. by J. Alderfer, pub.2006
bowa = Birds of Western Africa by Borrow and Demey, pub. 2004

Bill Color
boea — yellowish brown
boem — variable, usually yellowish with darker culmen
boej — yellow to brownish with irregular dark elements
ng — dusky yellow
bowa — does not discuss (shows dusky yellowish)

The ME/NH bird: slate black bill with pale gray on extreme base of lower mandible (seen in blowups of photos).

Bill Shape
boea — slightly decurved
boem — a little longer and deeper-based than Little Egret, almost always slightly curved
boej — thicker than Little Egret with slightly more curved culmen
ng — subtle decurviture at tip
bowa — heavier than Little Egret, slightly drooped tip

The ME/NH bird: Bill seems to be long, rather straight.

Leg and Feet Color
boea — legs dark green, yellow on feet extends half-way up tarsus
boem — legs greenish gray-black to halfway or more down tarsus, rest of tarsus and toes dull yellow, legs can be more extensively grayish yellow
boej — legs dark with greenish yellow to yellow tones, subspecies schistacea (in India) has yellow feet and tarsus or patchy yellow tarsus; subspecies gularis (in Africa) legs dark brown, feet bright yellow
ng — legs black, feet yellow, feet black during courtship
bowa — greenish black legs, yellowish feet and lower legs

The ME/NH bird: Legs blackish all the way down to toes with slightly paler gray tibia (when dry, black when wet), toes bright yellow with a spur of yellow extending up the back of the tarsus for about 1 inch

Lores
boea — yellow (pictured dark)
boem — blue-gray, reddish during courtship
boej — (shows dark or pale gray, does not discuss)
ng — dusky yellow, red during courtship
bowa — does not discuss (shows dusky yellow)

The ME/NH bird: lores are dark bluish gray

Wings
boea — does not discuss
boem — does not discuss
boej — does not discuss
ng — does not discuss
bowa — variable white patch on primary coverts (shows obvious white outer primary greater coverts)

The ME/NH bird: Has an all-dark wing except for a small pale area at the base of the primary greater coverts (only seen in some flight postures from photos where primary coverts are lifted)

Going by the field guides alone, the ME/NH bird looked most like the dark morph Little Egret illustrated in Birds of East Africa.

Since then we have researched this issue and talked to many people and gotten some interesting feedback. Most of this information is about the taxonomy of Little Egret, Western Reef-Heron, and Dimorphic Egret, all of which have been split and lumped in just about any way that you could dream up.

But, it turns out that a highly-respected german researcher, Andreas Helbig, was doing work on the relationship of these species just before he recently died. A brief mention of his results and beliefs was kindly sent to us by Nikolas Haass from Philadelphia, a fellow of the Delaware Valley Ornithological Club and a member of the New Jersey Bird Records Committee. With his permission, here is a copy of his communication. (For clarification, there is both a Western and Eastern African population of Reef-Herons.)

Dear Lillian, Don and Jersey Birders,

Firstly, I don't have any doubts about the ID of the
Maine bird. I think it is a 'Western Western Reef
Heron', which I called 'Southern Little Egret' below.
Interestingly Eastern Western Reef Heron is commonly
kept in captivity and thus a frequent escapee. Western
Western Reef Heron seems not to be that common in
captivity. Thus, the bird might even be a 'wild' bird!
However, they are no long distance migrants... But I
don't want to discuss that, I'd rather wanted to give
more information or confusion concerning the taxonomy:

More details of the Western Reef Heron taxonomy:
gularis (Bosc, 1792), breeds at the West African
coast, schistacea (Hemprich & Ehrenberg, 1828) breeds
at the Indian Ocean coast, dimorpha (Hartert 1914)
breeds on islands in the Indian Ocean (CRAMP & SIMMONS
1977; HANCOCK & KUSHLAN 1984; DEL HOYO et al. 1992).

BAUER & GLUTZ VON BLOTZHEIM (1966); PAYNE & RISLEY
(1976); CRAMP & SIMMONS (1977); PAYNE (1979);
SIBLEY & MONROE (1990); SVENSSON et. al. (2000) treat
Western Reef Heron as a separate species.

HANCOCK & KUSHLAN (1984), DEL HOYO et al. (1992)
however, treat all forms of Western Reef Heron as
subspecies of Little Egret: Egretta garzetta gularis,
Egretta garzetta schistacea und Egretta garzetta
dimorpha.

VOISIN (1991) treats Dimorphic Heron Egretta gularis
dimorpha as subspecies of Western Reef Heron.

BAUER & GLUTZ VON BLOTZHEIM (1966); CRAMP & SIMMONS
(1977) treat Dimorphic Egret Heron Egretta gularis
dimorpha as subspecies of Little Egret Egretta
garzetta dimorpha (although they treat Western Reef
Heron as a separate species: E. gularis gularis and E.
gularis schistacea)

PAYNE & RISLEY 1976; PAYNE 1979. SIBLEY & MONROE
(1990) treat Dimorphic Egret as a separate species:
Egretta dimorpha ("Mascarene Reef-Egret" in SIBLEY &
MONROE 1990).

WOLTERS (1976) treats the Eastern form of Western Reef
Heron as separate species: Egretta schistacea.

The late Andreas Helbig (he is the one who split
European Larus argentatus and American Herring Gull L.
smithsonianus) summarized his work in Bauer et al.
(2005) (cf. also BARTHEL IN SVENSSON et at. 2000):
The Western (Atlantic) form of Western Reef Heron
Egretta [garzetta] garzetta gularis seems to be a
southern SUBSPECIES of LITTLE EGRET Egretta [garzetta]
garzetta. Similar to Snow Goose and 'Blue Goose' which
originally were geographically separate populations of
the same species, the southern subspecies of Little
Egret (gularis) occurs predominantly in the dark
morph.
In contrast, the Eastern (Indian Ocean) form of
Western Reef Heron Egretta schistacea (formerly
Egretta gularis schistacea) seems neither closely
related to Little Egret nor to 'Western' Western Reef
Heron (better 'Southern' Little Egret, this name is my
personal input), but seems to be a different species
and NOT even a member of the superspecies Egretta
[garzetta]!
On the other hand the Madagaskar form Egretta
[garzetta] dimorpha might be a separate species within
the superspecies Egretta [garzetta]!

Of course Eastern Reef Heron Egretta sacra remains
a different species.

A German summary of all that will be found in HAASS
(in press) and a summarizing German ID paper to all
the confusing egrets has been published in Limicola
(HAASS 1997).


BAUER, K.M. & U.N. GLUTZ VON BLOTZHEIM (1966):
Handbuch der Vögel Mitteleuropas. Bd. 1. - Frankfurt
am Main.
BAUER, H.G., E. BEZZEL & W. FIEDLER (2005): Das
Kompendium der Vögel Mitteleuropas. - Wiebelsheim
(Aula).
CRAMP, S. & K.E.L. SIMMONS (1977): Handbook of the
Birds of Europe, the Middle East and North Africa. The
Birds of the Western Palearctic. Vol. 1: Ostrich to
Ducks. - Oxford, London, New York (Oxford University
Press).
HANCOCK, J. & J. KUSHLAN (1984): The Herons Handbook.
Paintings by R. GILLMOR & P. HAYMAN. - London & Sydney
(Croom Helm).
HAASS, N.K. (1997): Rätselvogel 62: Küstenreiher
Egretta gularis. Limicola 11: 310-311.
HAASS, N.K. (in press): Egretta gularis Bosc, 1792.
Küstenreiher. In: HÖLZINGER, J. (in press): Die Vögel
Baden-Württenbergs 2.1. - Stuttgart.
HOYO, J. DEL, A. ELLIOTT & J. SARGATAL (1992):
Handbook of the Birds of the World. Vol. 1: Ostrich to
Ducks. - Barcelona (Lynx Edicions).
PAYNE, R.B. (1979): Ardeidae. In MAYR & COTTERELL
(eds.). Peter’s Check List of the Birds of the World
(2nd ed.). Mus. Comp. Zool., Cambridge, Mass.
PAYNE, R.B. & C.J. RISLEY (1976): Systematics and
evolutionary relationships among the herons
(Ardeidae). Univ. Mich. Mus. Zool. Misc. Publ. No.
150.
SIBLEY, C.G. & B.L. MONROE (1990): Distribution and
Taxonomy of Birds of the World. New Haven.
SVENSSON, L, P. GRANT, K. MULLARNEY & D. ZETTERSTRÖM.
(2000): Vögel Europas, Nordafrikas und Vorderasiens.
Stuttgart.
VOISIN, C. (1991): The Herons of Europe. London (T &
AD Poyser).
WOLTERS, H.E. (1975-1982): Die Vogelarten der Erde. -
Hamburg und Berlin (Parey).

Summing up where things now stand

Nothing is finalized, but it may be that the ME/NH bird could be called a dark morph (Southern) Little Egret. Little Egrets do breed on Barbados and the Nat. Geo. Guide says that dark morph Little Egrets breed there too (we are presently trying to confirm this). It is possible that dark morph (Southern) Little Egrets migrate north from Barbados in spring and south in fall and this is why we see them on the East Coast. All of this is still conjecture and of course the taxonomy suggested above has not been officially accepted by the American Ornithologists' Union. Still there is much room for thought, discovery, and research on these exciting birds.

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