Endangered Species in the Pacific Islands
Micronesian Megapode / Megapodius laperouse / sasangat or sasangal
The Micronesian megapode is a pigeon-sized bird with an average weight of about 12.25 ounces (3.8 grams). It has a dark gray to black body plumage and an ash gray head with a slightly darker, short, rough crest.
The flight feathers and short tail are grayish-black, and the wings are short and round. The bill is yellow with the upper mandible clove-brown to black at the base. The feathers around the eye, ear, and throat are very sparse or absent revealing red skin and a red throat patch. The heavily built legs and feet are yellow with the joints of toes and/or all the upper surface dark gray-black.
|Micronesian Megapode - Photo credit USFWS
Habitat & Behavior:
The Megapodiidae are part of a family within the order Galliformes (chicken-like birds) found only in the Australasian region. The family is comprised of seven genera found in Australasia (Australia, New Guinea and surrounding islands, eastern Indonesia, the Nicobar Islands, the Philippines, Micronesia, Vanuatu, and Niuafo`ou of the Tonga Islands). The Micronesian megapode is generally a bird of the forest.
Megapodes are sometimes called “incubator birds” because they rely on solar energy, volcanic activity, or microbial decomposition as a heat source for incubation. They are also characterized by laying large eggs without an air chamber. Chicks lack an egg tooth at hatching and kick their way out of the egg. Megapode chicks are precocial (feathered, able to walk, and able to regulate their body temperature) at hatching and the adults do not care for the young.
The Micronesian megapode seems to be an omnivore, taking a variety of plant and animal foods available on the forest floor, including seeds, beetles, ants, other insects, and plant matter.
Micronesian megapodes are known to give at least three types of calls, including two calls that are different for males and females and that may be given in a duet. Duetting in birds is correlated with year-round territorial behavior and life-long pair bonds.
Past & Present:
The Micronesian megapode was historically widespread throughout the Mariana Island chain but declined on all of the southern Mariana Islands (Guam, Rota, Aguiguan, Tinian, and Saipan) in the 19th and early 20th centuries. While the megapode was extirpated on Guam, Tinian, and Rota, a small, remnant population persists on Aguiguan along with a very small (possibly reintroduced) population on Saipan.
The megapode remains in relatively large numbers only on the smaller, mostly uninhabited northern islands of Anatahan, Sarigan, Guguan, Pagan, Maug, Alamagan, Ascuncion, and possibly Agrihan. Population estimates of the megapode total about 1,440 to 1,975 birds in the island chain.
The decline in numbers is thought to be a result of exploitation and habitat loss and degradation. Overgrazing by feral goats, cattle, and pigs has had a profound effect on the vegetation of the islands. In addition to possible direct human predation, megapodes are known to be preyed on by introduced monitor lizards and may also be preyed on by feral dogs, cats, and pigs.
A serious potential threat to megapode populations is the establishment of the brown tree snake from Guam to other islands in the Marianas archipelago. The brown treesnake was accidentally introduced to Guam shortly after World War II and has systematically spread throughout the island, causing the loss of nearly all of the avifauna (birds) and some of the other native vertebrate and invertebrate species of Guam.
The U.S. Fish and Wildlife Service (Service) listed the Micronesian megapode as endangered in 1970. In 1982, the Service conducted the Micronesian Forest Bird Surveys in the Marianas and determined the status of populations in the southern Marianas. More recent surveys have been completed for the islands of Rota, Tinian, Saipan, and Sarigan. Plans are underway to survey for Micronesian megapodes in all the northern Mariana Islands.
The CNMI government declared the islands of Guguan, Asuncion, Maug, and Uracas wildlife sanctuaries in the early 1980s, providing protected habitat for the megapode and other wildlife.