_Ardea sacra_ Gmelin, Syst. Nat., 1, pt. 2, 1789, p. 640. (Type
locality, Tahiti.)
_Ardea jugularis_ Kittlitz, Observ. Zool., in Lutké, Voy. "Le
Séniavine," 3, 1836, pp. 286, 299, 304 (Ualan, Lougounor, Guahan);
Hartlaub, Journ. f. Ornith., 1854, p. 167 (Mariannen); Kittlitz,
Denkw. Reise russ. Amer. Micron. und Kamchat., 2, 1858, p. 63
(Ualan); Pelzeln, Reise "Novara," Vögel, 1865, pp. 118, 162, 120,
121 (Puynipet, Ualan).
_Ardea (Herodias) atra_ Gray, Cat. Birds Trop. Is. Pacific Ocean,
1859, p. 48 (Ladrone or Marian Islands, Caroline Islands).
_Ardea sacra_ Hartlaub, Proc. Zool. Soc. London, 1867 (1868), p.
831 (Matelotas Islands); Hartlaub and Finsch, Proc. Zool. Soc.
London, 1868, pp. 8, 118 (Pelews); Finsch and Hartlaub, Journ. f.
Ornith., 1870, p. 137 (Pelews, Matelotas); Gray, Hand-list Birds,
3, 1871, p. 28 (Marian, Carolines, Pelews, Matelotas); Hartlaub
and Finsch, Proc. Zool. Soc. London, 1872, pp. 89, 104 (Pelew,
Uap, Ualan); Gräffe, Journ. Mus. Godeffroy, 2, 1873, p. 123 (Yap);
Finsch, Journ. Mus. Godeffroy, 8, 1875, pp. 5, 32 (Palau); _idem_,
Journ. Mus. Godeffroy, 12, 1876, pp. 18, 38 (Ponapé, Ualan);
_idem_, Proc. Zool. Soc. London, 1877 (1878), p. 781 (Ponapé);
_idem_, Journ. f. Ornith., 1880, pp. 294, 306 (Ponapé, Kuschai);
_idem_, Ibis, 1880, pp. 220, 330, 332 (Taluit); _idem_, Proc.
Zool. Soc. London, 1880, p. 577 (Ruk); _idem_, Ibis, 1881, pp.
105, 106, 109, 115 (Kushai, Ponapé); Schmeltz and Krause, Ethnogr.
Abth. Mus. Godeffroy, 1881, pp. 299, 353 (Mortlocks, Ruk); Finsch,
Mitth. Ornith. Ver. Wien, 1884, p. 51 (Jaluit, Kuschai); Oustalet,
Le Nat., 1889, p. 261 (Mariannes); Wiglesworth, Ibis, 1893, p. 211
(Marshalls); Oustalet, Nouv. Arch. Mus. Hist. Nat. Paris, (3), 8,
1896, p. 36 (Guam, Marshalls, Palaos, Carolines); Schnee, Zool.
Jahrbücher, 20, 1904, p. 390 (Marschall-Inseln).
_Demiegretta sacra_ Salvadori, Ornith. Papuasia, 3, 1882, p. 348
(Marshalls, Ualan, Ponapé, Ruck, Pelew, Mariannis); Wiglesworth,
Abhandl. Ber. Zool. Mus. Dresden, no. 6, 1890-1891 (1891), p. 67
(Marianne, Pelews, Luganor, Ruk, Ponapé, Ualan, Taluit); Hartert,
Novit. Zool., 5, 1898, p. 64 (Saipan); Sharpe, Cat. Birds British
Mus., 26, 1898, p. 137 (Pelew, Carolines, Marshalls); Hartert,
Novit. Zool., 7, 1900, p. 11 (Ruk); Seale, Occ. Papers Bernice P.
Bishop Mus., 1, 1901, p. 29 (Guam); Safford, Osprey, 1902, p. 67
(Marianas); _idem_, The Plant World, 7, 1904, p. 266 (Guam);
Kuroda, Avifauna Riu Kiu, 1925, p. 129 (Micronesia); Bryan, Guam,
Rec., vol. 13, no. 2, 1936, p. 15 (Guam); Bequaert, Occ. Papers
Bernice P. Bishop Mus., 16, 1941, p. 266 (Kusaie).
_Demigretta sacra_ Safford, Contr. U. S. Nat. Herb., 9, 1905, p.
79 (Guam); Prowazek, Die deutschen Marianen, 1913, p. 101 (Saipan,
Tinian); Cox, Island of Guam, 1917, p. 21 (Guam); Bequaert, Mushi,
12, 1939, p. 81 (Kusaie); Warton, Ecol. Monogr., 16, 1946, p. 175
(Guam); Warton and Hardcastle, Journ. Parasitology, 32, 1946, pp.
306, 316 (Ulithi, Guam).
_Demiegretta jugularis_ Takatsukasa and Kuroda, Tori, 1, 1915, p.
50 (Truk, Ponapé, Pelew).
_Demiegretta jugularis grayi_ Uchida, Annot. Zool. Japon., 9,
1918, pp. 484, 488, 490 (Ponapé).
_Demiegretta sacra sacra_ Kuroda, in Momiyama, Birds Micronesia,
1922, p. 36 (Guam, Saipan, Angaur, Luganor, Yap, Ngoli, Ruk,
Ponapé, Kusaie, Taluit).
_Demigretta sacra sacra_ Wetmore, in Townsend and Wetmore, Bull.
Mus. Comp. Zoöl., 63, 1919, p. 171 (Kusaie); Mathews, Syst. Avium
Australasianarum, 1, 1927, p. 198 (Carolines); Yamashina, Tori, 7,
1932, p. 406 (Ponapé); Hand-list Japanese Birds, rev., 1932, p.
183 (Saipan, Guam, Babelthuap, Peliliu, Angaur, Ngulu, Yap, Truk,
Lukunor, Ponapé, Kusaie, Jaluit, Majuro); Mayr and Amadon, Amer.
Mus. Novit., no. 1144, 1941, p. 10 (Guam, Saipan, Palau, Ponapé,
Kusaie, Ruk, Tah); Hand-list Japanese Birds, 3d ed., 1942, p. 203
(Saipan, Rota, Babelthuap, Peliliu, Angaur, Ngulu, Yap, Ulithi,
Truk, Lukunor, Ponapé, Kusaie, Jaluit, Arhno, Majuro, Moloclab,
Wotze, Likieb, Ailuk); Mayr, Birds Southwest Pacific, 1945, pp. 51,
284 (Micronesia); Downs, Trans. Kansas Acad. Sci., 49, 1946, p. 90
(Tinian); Strophlet, Auk, 63, 1946, p. 535 (Guam); Borror, Auk, 64,
1947, p. 417 (Agrihan); Stott, Auk, 64, 1947, p. 524 (Saipan);
Baker, Smithson. Misc. Coll., vol. 107, no. 15, 1948, p. 42 (Rota,
Guam, Peleliu, Ulithi, Truk).
_Demigretta sacra micronesiae_ Momiyama, Tori, 5, no. 22, 1926, p.
110 (Type locality, Caroline Islands; Pelew, Yap, Truk, Ponapé,
Kusaie).
_Geographic range._--Coasts of Asia and adjacent islands from Korea
and Japan south to Malaysia, Australia, Melanesia, Polynesia and
Micronesia. In Micronesia: Mariana Islands--Agrigan, Tinian,
Saipan, Rota, Guam; Palau Islands--Babelthuap, Koror, Garakayo,
Ngesebus, Peleliu, Ngabad, Anguar; Caroline Islands--Ulithi, Yap,
Ngulu, Truk, Lukunor, Ponapé, Kusaie; Marshall Islands--Jaluit,
Arhno, Majuro, Maloclab, Wotze, Likieb, Ailuk, Bikini, Eniwetok,
Kwajalein.
_Characters._--A medium-sized heron with three color phases: in
gray phase color of body varies from "deep blackish-slate" to
light bluish-slate, particularly on the breast, with a white gular
stripe; wear and fading causes the color of the body to change to
brownish-slate; bluish-gray ornamental plumes may be present on
adult; in white phase color of body is pure white in adult stage;
plumage of immature may be mottled; in mottled phase there may be
a variable amount of gray and white (for complete study of
plumages of _Demigretta sacra_ see Mayr and Amadon, 1941:4).
_Measurements._--Mayr and Amadon (1941:1) record the length of the
wing of thirty adults from the Marianas and Carolines as 268-309
(284). Seven adult males obtained by the NAMRU2 party at Rota,
Guam and Peleliu measure: wing, 287-307 (294); tail, 95-114 (101);
culmen, 91-101 (96); tarsus, 78-87 (82); seven adult females, from
Rota and Guam: wing, 265-285 (275); tail, 87-96 (91); culmen,
86-92 (89); tarsus, 72-79 (76).
_Weights._--The author (1948:42) lists the following weights: four
adult males from Guam (gray phase) 590-667 (614); two adult males
from Guam (white phase) 600 and 662; five adult females from Guam
and Rota (gray phase) 477-553 (506).
_Specimens examined._--Total number, 80 (38 males, 40 females, 2
unsexed) as follows: Mariana Islands, USNM--Rota, 3 (Oct. 18, Nov.
2, 5)--Guam, 21 (May 11, June 6, 18, July 6, 8, 16, 24, 27, Aug. 6,
8, 27); AMNH--Saipan, 2 (July 22)--Guam, 9 (Feb. 11, Mar. 6, 7,
April 11, Aug. 15, Sept. 14, 16, Nov. 27, Dec. 20); Palau Islands,
USNM--Peleliu, 3 (Sept. 10, 16); AMNH--exact locality not given, 5
(Nov. 8, 21, 23); Caroline Islands, USNM--Ulithi, 1 (Aug.
15)--Kusaie, 1 (Feb. 8); AMNH--Truk, 3 (Feb. 18, May 20, Nov.
5)--Tah, 2 (Oct. 18)--Ponapé, 2 (Nov. 21, undated)--Kusaie, 26
(Jan. 25, 26, Feb., Mar. 10-20, 20-30, April 1-10, 18); Marshall
Islands, USNM--Bikini, 2 (March 29, April 2).
_Nesting._--The Reef Heron apparently nests on most of the islands
in Micronesia. The eggs are laid in a nest of grass and twigs on or
near the ground. Hartert (1898:64) records a nest found in grass at
Saipan on July 28, 1895. Yamashina (1932a:406) reports on one egg
taken at Ponapé on July 23, 1931. Marshall (1949:219, fig. 37)
found a breeding bird in April at Tinian. Coultas (field notes)
learned from the natives at Ponapé that the Reef Heron builds
a nest of small sticks near the ground in the mangrove thickets.
Two or three eggs are laid, and nests can be found at various times
of the year. Mayr and Amadon (1941:4) comment on the prolonged
breeding season and report six sets of eggs from Polynesia taken in
January, March, April, September, October, and November.
_Food habits._--The author (1948:42) found fish and crabs in the
stomachs of birds taken at Guam, Ulithi and Peleliu.
_Parasites._--Uchida (1918:484, 488, 490) found the following bird
lice (Mallophaga) on the Reef Heron at Ponapé: _Nirmus orarius_,
_Colpocephalum importunum_, and _Myrsidea teraokai_. Bequaert
(1939:81 and 1941:266) found the fly (Hippoboscidae),
_Ornithoctona plicata_, on the heron at Kusaie. Wharton (1946:175)
and Wharton and Hardcastle (1946:306, 316) obtained chiggers
(Acarina), _Neoschöngastia egretta_ and _N. carveri_, from the
Reef Heron at Guam and Ulithi.
_Remarks._--The species _Demigretta sacra_ contains two subspecies, the
widespread _D. s. sacra_ and a larger form, _D. s. albolineata_ (Gray),
known from New Caledonia and the Loyalty Islands. The latter subspecies
is surrounded by the former, a distribution which closely parallels that
in each of the species _Phalacrocorax melanoleucus_ and _Gygis alba_ of
Oceania. Recently Delacour (in Delacour and Mayr, 1945b:105) has dropped
the name _Demigretta_ placing all of the forms of this genus in
_Egretta_. He says, "We cannot accept the genus _Demigretta_, which is
based on the more extended feathering of the tibia, the different length
and texture of the feathers of the trains, the shortness of the tarsus
and the presence of a dark gray color phase. The latter exists in the
Madagascan and African subspecies of _Egretta garzetta_."
The Reef Heron is a conspicuous member of the bird life of Micronesia,
being recorded from most of the island groups. It prefers the placid and
shallow waters of the lagoons and tidal beaches where it obtains the
littoral animal life as food. The birds are seldom seen inland and
usually frequent the beaches and rocky coasts. In this respect there is
little opportunity for competition with the migratory Plumed Egret,
which prefers the grassy upland and marsh areas and inland ponds. The
Reef Heron is a quiet, usually solitary, and retiring bird, being
exceedingly difficult to approach, especially when found on the open
tidal flats.
The problem of plumages and color phases in the Reef Heron has been
treated by Mayr and Amadon (1941:4-10). Specimens which they examined
from Micronesia were found to be 54 percent gray, 40 percent white, and
6 percent mottled. Of the birds obtained by NAMRU2 field parties, fewer
than 40 percent were white. Field counts showed a considerable variation
in the ratio of grays to whites: Guam--6 grays to 4 whites; Ulithi--4
grays, 6 whites, 1 mottled; Palau--equal number of grays and whites;
Truk--2 whites, 1 gray, 1 mottled. For some unknown reason, the gray
birds were more easily approached than the white birds. Gleise and
Genelly (1945:221) saw one white Reef Heron at Eniwetok. Wallace (field
notes) found white herons more numerous than gray ones at Kwajalein in
1944 and 1945. Borror (1947:417) observed gray birds at Agrigan. Stott
(1947:524) saw one blue heron on December 24, at Saipan. The 150 birds
seen by him at Lake Susupe in December probably were Plumed Egrets.
In discussing the variation in the color phases of the Reef Heron
throughout its range, Mayr (1924b:237) suggests that the reduced
variability of small populations may not be due to accidental gene loss,
but instead to the population having descended from a single pair or
from one fertilized female. The descendents would naturally possess only
those characters provided for in the genetic make-up of the parents.
Reef Herons on New Zealand and in the Marquesas Islands all are gray,
while at other island groups different proportions of gray and white
individuals occur; such phenomena may result because of the genetic
constitution of the "founders."
=Nycticorax nycticorax nycticorax= (Linnaeus)