7 Nisan 2013 Pazar

Guam Territorial Bird

Guam Territorial Bird

Guam Rail (common name) 
Gallirallus owstroni 
(scientific name)

Overview

The Guam rail, known as ko’ko’ in the Chamorro language, is a small, shy brown bird of the forest undergrowth. It is the size of a small chicken or duck with a longer, pointed beak, smaller but very muscular legs, and very long toes that help it walk on marshy ground. It has a white band over its eyes, a banded brown-and-white chest and wings, and a short tail. Females are similar in appearance, but slightly smaller than males. The Guam rail is an omnivorous bird that feeds on worms, insects, small lizards, snails, fish, bird eggs, carrion, seeds, fruit, and even palm leaves. It is almost completely flightless, but can fly 3 to 10 feet (1 to 3 meters) if threatened.
Although native to Guam, the Guam rail was completely extinct in the wild by the 1980s and has yet to actually be re-introduced to the island from the captive breeding programs that have saved the bird from total extinction. The Guam rail was declared the official bird of the island territory in 2000. (Previously, that designation had been held by the Mariana fruit dove.)

Close-up

STATUS
Official
ALSO KNOWN AS
Ko’ko’
PHYSICAL DETAILS
  MaleFemale
 SizeLength to end of tail: 11 in (28 cm)
Wing from flexure: 2.1 in (5.4 cm)
Length of tail: 1 in (2.5 cm)
Length to end of tail: 11 in (28 cm)
Wing from flexure: 2.1 in (5.4 cm)
Length of tail: 1 in (2.5 cm)
 Weight6–10.6 oz (170–300 g)6–10.6 oz (170–300 g)
BEHAVIOR
Rails are stealthy birds that make hardly any noise as the forage in the dense forest underbrush. The Guam rail breeds up to 10 times a year in shallow nests of grass and leaves placed in low, dense grassy or reedy vegetation close to water. Both parents build the nest and both feed and care for their young, although females spend more time incubating the eggs. The Guam rail is almost entirely silent except for a loud, piercing whistle used when there are other rails present or in extreme danger. It is a highly territorial bird, especially during breeding season.
HABITAT
Moist tropical forests, grasslands, scrub, fern thickets, and moist wetland habitats.
Range: Exists in small, protected areas on Guam and the nearby island of Rota in the Northern Marianas as well as at 17 zoos in the United States. Its traditional range is the island of Guam.
Migration: Non-migratory.
Conservation Status: Extinct in the wild due to hunting, egg predation by non-native brown tree snakes and rats, and attacks by feral cats. A captive breeding program based on a few of the last remaining birds captured in the wild in Guam in the 1970s and 1980s has introduced several dozen of the birds to protected areas in Guam and the Northern Marianas’ island of Rota, but their ability to survive is as yet unknown. Guamanian law protects both locally and federally listed endangered species and prohibits the taking, buying or selling of wild birds or their eggs.
NESTING
Nesting Period: year-round
Size of Clutch: 1–4 eggs
Incubation Period: 19 days
Egg Description: Speckled brown oval
Egg Size
: 1.3 x .8 in (3.1 x 2.1 cm)
SIMILAR SPECIES
Buff-banded rail, barred rail, Roviana rail, Cocos buff-banded rail.
TRIVIA
  • Although virtually flightless, the Guam rail can swim and dive using its wings underwater.
  • Chicks reach adult weight at seven weeks of age and are able to breed at only four months of age.
  • Several U.S. zoos are participating in a breeding program to preserve the ko’ko’ from extinction.

Click to enlarge an image
State Bird
Illustration of Guam Rail
State Bird
Guam Rail

CLASSIFICATION
Kingdom:Animalia
Phylum:Chordata
Class:Aves
Order:Gruiformes
Family:Rallidae
Genus:Gallirallus
Species:G. owstoni
Author: World Trade Press


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