Measurements.—Two males measure: wing 180?, 182?; tail 62, 63; tarsus 55, 55; three females: wing 181?, 181?; tail 55, 59, 62; tarsus 54, 54, 56. Takatsukasa (1932: 10) lists the following measurements: males—wing, 155-169; tail, 54-62; culmen, 22.5-24; tarsus, 51-54; females—wing, 158-170; tail, 56-65; culmen, 23-25; tarsus, 50-55.
Specimens examined.—Total number, 10 (3 males, 4 females, 3 unsexed), as follows: Mariana Islands, AMNH—Guam, 1 (June 6)—Saipan, 6 (1895)—Asuncion, 3 (1904).
Nesting.—Concerning the nest of the Micronesian Megapode in the Marianas, Takatsukasa (1932:10) writes: "The nest is a large mound of sand mixed with grass and is made in the wooded land along the seashore. The mound is over one hundred feet in circumference and a few yards in height, and is built by the united efforts of the male and female, by scratching sand and grass with their large feet. The eggs are laid in this mound and they are hatched by the heat of the sun and that produced by the fermentation of the grass, and they are never hatched by the parent birds. The egg is of a pale brown, but always stained by nesting materials."
Takatsukasa (1932:11) quotes Oustalet as follows: "Specimens collected by Mr. Marche have proved that the breeding season of La Pérouse's Megapode is rather long, like the other species of the same family, it begins to breed in January or February and ends in June. Accordingly, in this period the eggs just laid, the chicks, the young and adult can be seen at one place, but Mr. Marche did not obtain any egg." Hartert (1898:61) records a chick taken on July 17. Yamashina (1932a: 411) records eggs taken in 1931 as follows: two eggs from Pagan, February 17; three eggs from Pagan, May 15; four eggs from Agrihan, June 24. The breeding season for both of the incubator birds, M. l. senex and M. l. lapérouse, is apparently from about January to August.
Remarks.—The Micronesian Megapode was first taken in the Marianas by the expedition of the Uranie. Bérard, a member of the expedition, obtained the bird at Tinian in December, 1820. Quoy and Gaimard (1824:27), who studied the birds of this expedition, reported that according to native tradition the species was in former times widely distributed in the Marianas and domesticated by the ancient people of the islands, but that in 1819 and 1820 the birds were not numerous on Tinian and not found on Guam and Rota. Marche (in Oustalet, 1896:27) obtained twenty-three birds at Saipan, one from Rota, two from Agrihan, and five from Pagan in 1887, 1888, and 1889; it is apparent that Quoy and Gaimard missed the bird at Rota. Marche was of the opinion that the megapodes were never domesticated and that they would probably not last much longer at Saipan and Rota owing to the incessant hunting for them by the natives. As in the Palaus, the natives apparently prefer the eggs to the adults. The latest collections of these birds in the Marianas were made by the Japanese. Yamashina (1932:411) obtained eggs in 1931 at Pagan and Agrihan, and again in 1940. He (1940:679) reported birds at Assongsong (Asuncion). Takatsukasa (1932:12) says, "A collector, working for Marquis Yamashina and myself, lately procured many specimens in Saipan and Pagan." Linsley (1935:249, 250) in searching for the megapode at Guam found little evidence of the birds. He interviewed people between the ages of forty-five and eighty and only two or three remembered seeing the bird. He said he saw one or two cross the road; but I suspect that they might have been rails (Rallus owstoni). Service personnel stationed at various islands in the Marianas during the late war have not reported the birds. The NAMRU2 party found no trace of the bird at Guam or Rota. Joe T. Marshall, Jr. (1949:203), did not find the bird at Saipan, Tinian, or Guam in 1945. Its status on Agiguan is unknown; isolated Japanese troops present on this small island from the time of the American invasion (1944) until the armistice (1945) may have used the birds for food and depleted the population seriously. At present the birds apparently still occur on islands in the northern Marianas. It seems that if these birds are to survive, they must be given some protection.
Evolutionary history.—The genus Megapodius consists, according to Peters (1934:1-7), of nine species which are distributed through the islands from the Philippines and Borneo to Australia and Melanesia. These have been redesignated under three specific names by Mayr (1938). Outlying forms occur in the Nicobar Group to the west and in Tonga (Niuafou Island) in the east and in the Palaus and Marianas to the extreme northeast. Lister (1911:757) is of the opinion that the megapodes may have reached these outlying islands by having been transported by the natives, by whom the eggs were highly valued as food. This idea is also maintained by Rutland (1896:29-30) and Christian (1926:260). Possibility and not factual evidence support this hypothesis. From their seeming ancestral stocks, M. pritchardii Gray of Niuafou Island and M. lapérouse of Micronesia are remarkably distinct which may indicate their early arrival at these islands and subsequent change from their ancestral stocks.
Like M. pritchardii, the Micronesian species is smaller than its relatives to the southwest and has short, rather rounded wings, although its feet are heavily built whereas those of M. pritchardii are lightly constructed. In comparing these birds with the species of megapode found in the Philippines, Celebes and Melanesia, it seems that both M. pritchardii and M. Lapérouse are closely related to the widespread species, M. freycinet, which may have been ancestral to both. The differences between M. prichardii and M. lapérouse indicate that they represent independent invasions. Nevertheless these megapodes may have had a wider range in Oceania in former times; man may have eliminated the birds from some islands by using their eggs. The eggs are laid in conspicuous mounds which are easily found by man.
M. lapérouse differs from M. freycinet of New Guinea and other parts of Melanesia and the Philippines; its small size, short wing and pearl gray head are distinctive characters. It shows greatest resemblance to the subspecies in Celebes (M. f. gilberti) in size and to the subspecies in the Moluccas (M. f. freycinet) in coloring; possibly M. lapérouse represents stock from one of these regions. Apparently the group as a whole evolved from a center of dispersal in the New Guinea area. Mayr (1942b:167) regarded all the species of Megapodius as belonging to one polytypic species, except M. lapérouse and M. pritchardii, which are allopatric species.