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Last updated on April 17, 2014 at 11:16 EDT

Common Gallinule, Gallinula chloropus

The Common Gallinule (Gallinula chloropus) is a bird that is a member of the rail family. This bird can be found primarily scattered outside of Australasia as well as many tropical rain forests, deserts, and the polar regions. In other parts of the world this bird is known as the common moorhen. The Common Gallinule is an American term which also refers to the subspecies G. c. cachinnans. “Moor coot” is misleading because G. chloropus is not a coot, but it is usually referred to as “water rail” (Rallus aquaticus). This bird is also referred to as simply “moorhen” or “waterhen” because it prefers wetlands to moorland; both terms may refer to a number of related species. “Watercock” is the rail species (Gallicrex cinera) which is not a male “waterhen”. Because this bird is common worldwide there is a diversity of names in numerous places; apart from coots, Common Gallinules are the most familiar rail species outside of the Australian region to most people.

The Common Gallinule has unique characteristics. Apart from the white under-tail, it has dark plumage, a red facial shield and yellow legs. Younger gallinules lack the red shield and are browner. When this bird is threatened it will make a loud emit hissing sound. This bird has a wide range of gargling calls.

The gallinule is a common breeding bird that resides in well-vegetated lakes and marsh environments. The gallinules that populate colder areas where the water freezes, such as northern USA, southern Canada and Eastern Europe, will migrate toward temperate climes. The gallinule consumes small aquatic creatures and a variety of vegetable material. This bird will forage while swimming or walking through marshland. It can be tame in some areas though it is usually secretive. The Common Gallinule remains abundant and widespread though it has lost its habitat in parts of its range.

In dense vegetation the gallinule will build its nest which is a roofed basket on the ground. Between mid-March and mid-May in the Northern hemisphere temperate regions this bird will begin to lay its eggs. In the early season females will lay about 8-12 eggs. In the summer a second brood usually occurs, however the female normally lays 5-8 eggs, sometimes less. Sometimes females will share nests. Both the male and female gallinules incubate and feed their young; incubation generally last about three weeks. After 40-50 days these fledge and after a few weeks the young will become independent and come spring raise their first breed. If threatened, the immature birds may cling to their parents’ body; from there the adult bird takes flight to find safety, carrying their offspring.

Regardless of being a abundant species, smaller residents are more likely to become extinct. The Small Indian Mongoose (Herpestes javanicus) is a threat to the Hawaiian moorhen or “˜alae “˜ula (G. c. sandvicensis). The Small Indian Mongoose was first introduced to the Hawaiian Islands in-order-to hunt rats, however this species found the local bird-life easier to hunt. Due to construction in its habitat the Mariana Common Moorhen or pluattat (G. c. guami) is rare. In 2001 only 300 adult birds remained, and since 1984 this bird was listed as endangered both locally and federally. Belonging to the widespread subspecies G. c. orientalis and locally known as debar on Palau (which is a generic term that is also referring to ducks, meaning “waterfowl”) this bird is very rare here and is hunted by locals. Angaur and Peleliu (on the archipelago) is where most of the population resides, while the species is most likely gone from Koror. A few dozen species still occur in the Lake Ngardok wetlands of Babeldaob, however the complete number of the Common Gallinule is roughly in the same region as the Guam population; 100 or less adult birds (typically less than 50) have come across in survey. The Common Gallinule is as plentiful as its vernacular name implies (on a global scale), therefore it is considered a Species of Least Concern by the IUICN. The cyclocoelid flatworm parasite (Cyclocoelum mutabile) was first described from the Common Gallinule and the Eurasian coot (Fulica atra).

Today there are roughly one dozen subspecies that are considered valid; a few more have been characterized and are now considered junior synonyms. Most are not recognizable because the differences are often subtle. Typically, the region and location of the sighting is the best indication of the subspecies, however this is not always reliable. Old World birds have a tail-ward margin of the red featherless area in a smooth waving line. The Old World birds also have a frontal shield with rounded top and parallel sides. American birds also have a fontal shield that is has a straight top and is less wide near the bill, giving a marked indentation of the red area to the back margin. There are two Pleistocene populations that are known from fossils. The fossils were distinct birds (usually larger) and most likely the immediate ancestors of today’s Common Gallinules. From the deposits in Florida’s Ichetucknee River showed the long-winged and stout paleosubspecies. It was initially described as a distinct species.

Image Credit: National Biological Information Infrastructure/Wikipedia

Common Gallinule Gallinula chloropus