_Ardea intermedia_ Wagler, Isis, 1829, p. 659. (Type locality,
Java.)
_Egretta intermedia intermedia_ Hand-list Japanese Birds, rev.,
1932, p. 183 (Koror); Hand-list Japanese Birds, 3d ed., 1942, p.
203 (Koror); Mayr, Birds Southwest Pacific, 1945, p. 302 (Palau);
Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 42 (Rota,
Guam, Peleliu, Angaur, Ulithi).
_Egretta intermedia_ Wharton and Hardcastle, Journ. Parasitology,
32, 1946, pp. 306, 310 (Ulithi); Baker, Ecol. Monogr., 16, 1946,
p. 408 (Guam).
_Geographic range._--India and Ceylon east to Malaysia,
Philippines, China and Japan. In Micronesia: Mariana
Islands--Saipan, Rota, Guam; Palau Islands--Koror, Peleliu, Angaur;
Caroline Islands--Ulithi.
_Characters._--Adult: A large white heron with green facial skin;
black legs, feet and toes. In breeding plumage: Head with crest;
neck and back with ornamental plumes; bill black. Winter plumage:
Without crest or plumes; bill yellow with blackish tip. Immature:
Resembles adult in winter plumage, but feathers soft and downy.
_Measurements._--Five males from Saipan, Rota, Guam, and Angaur
measure: wing, 295-321 (308); tail, 112-127 (119); culmen, 85-87
(87); tarsus, 111-118 (114); three females from Saipan, Ulithi,
Angaur: wing, 294-301 (297); tail, 101-116 (110); culmen, 77-83
(80); tarsus, 108-115 (107).
_Weights._--The author (1948:43) records the weights of two males
from Guam as 445 and 463.
_Specimens examined._--Total number, 8 (5 males, 3 females), as
follows: Mariana Islands, USNM--Saipan, 2 (Sept. 29, Oct. 2)--Rota,
1 (Oct. 31)--Guam, 2 (June 13); Palau Islands, USNM--Angaur, 2
(Sept. 21); Caroline Islands, USNM--Ulithi, 1 (Aug. 15).
_Food habits._--The NAMRU2 party found grasshoppers, other insects,
spiders and lizards in the stomachs of egrets taken at Guam,
Ulithi, and Angaur.
_Parasites._--Wharton and Hardcastle (1946:306, 310) obtained the
chiggers (Acarina), _Neoschöngastia egretta_ and _N. ewingi_, from
this egret from Ulithi.
_Remarks._--The NAMRU2 party obtained Plumed Egrets at Rota, Guam,
Ulithi, and Angaur in 1945. Previously, the only known record was from
Koror, as reported in the Hand-list of Japanese Birds (Hachisuka _et
al._, 1932:183). In addition, in 1945, Joe T. Marshall, Jr., obtained
two birds at Saipan, and Gleise (1945:220) reported seeing "white
herons" at Tinian, which probably were egrets. Gleise estimated the
number of these birds at Tinian to be fifty; he found them in swampy
areas. At Rota, the NAMRU2 party found a flock of sixteen birds in a
cultivated field on October 31. At Guam, egrets were first observed on
February 25, 1945, when a flock of fourteen was found in a fallow rice
paddy near Piti. This flock remained in this area and were seen
occasionally until as late as June 13, when two were taken as specimens.
A short time later (June 30) the entire area was cleared for military
use and the birds were seen no more. At Agfayan Bay a flock of sixteen
birds was found on the beach on July 24 and on August 6. These birds
kept apart from Reef Herons which were also in the area. In June, 1946,
M. Dale Arvey observed egrets in swamps along the Ylig River at Guam. At
Ulithi Atoll, three egrets were seen on August 15 at Potangeras Island,
feeding in grassy areas adjacent to the beach. In the southern Palaus,
the NAMRU2 party found egrets in August and September on tidal flats and
open grasslands at Peleliu and Angaur. At Peleliu, a flock of
twenty-five birds was seen on September 8 and a flock of eight birds on
September 16. At Angaur approximately twenty birds were seen in groups
of five or more on September 21. These birds, unlike the Reef Herons,
preferred grasslands to beach areas for feeding and were usually seen in
sizeable flocks.
There was no evidence of breeding; specimens examined were either
immatures or adults in winter plumage, since they had yellow bills
tipped with black and slight or no development of ornamental plumes.
Birds taken at Guam in June and at Angaur in September had no ornamental
plumes, while birds taken at Ulithi in August, at Saipan in September
and October, and at Rota in late October show some development of the
back plumes. Wharton and Hardcastle (1946:306) found the same species of
chigger on Plumed Egrets from Ulithi and from Okinawa in the Riu Kiu
Islands. The NAMRU2 party observed the birds in Micronesia from
February until October in 1945, and although the Plumed Egret may be
considered as merely a visitor to Micronesia, it would not be surprising
to find nests there. The fact that several new distributional records
were obtained for Micronesia in 1945 may indicate that the birds have
been overlooked by ornithologists in the past or that the birds are
increasing the breadth of their winter (or breeding?) range.
=Demigretta sacra sacra= (Gmelin)