Moorhens are medium-sized water birds in the genus Gallinula, Latin for 'little hen', in the rail family Rallidae. The genus currently includes seven species, of which one is extinct, and two others probably are. Three species formerly included in Gallinula have been found to have enough differences to be placed in two separate but closely related genera, Paragallinula (with one species, lesser moorhen Paragallinula angulata), and Tribonyx, the two native hens of Australia; Tribonyx differs visually by shorter, thicker and stubbier toes and bills, and longer tails that lack the white signal pattern of typical moorhens. The moorhens are also close relatives of the coots (Fulica),

Species

The genus contains five extant, one recently extinct, and two possibly extinct species.

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|150px ||Gough moorhen || Gallinula comeri <small>J. A. Allen, 1892</small> || Gough Island off Tristan da Cunha. Introduced on Tristan da Cunha as ecological replacement for extinct G. nesiotis. Formerly sometimes placed in Porphyriornis.

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| ||Makira woodhen || Gallinula silvestris <small>(Mayr, 1933)</small> || Makira (the Solomon Islands), extremely rare with no direct observations in recent decades, but still considered likely extant due to reports of the species persisting in small numbers. Sometimes placed in Pareudiastes if that genus is considered valid or Edithornis.

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|150px ||Samoan woodhen || Gallinula&nbsp;pacifica&nbsp;<small>(Hartlaub&nbsp;&&nbsp;Finsch,&nbsp;1871)</small> || Samoa, possibly extinct (1907?). Sometimes placed in Pareudiastes if that genus is considered valid.

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Species formerly included in the genus:

  • Lesser moorhen Paragallinula angulata
  • Black-tailed nativehen Tribonyx ventralis
  • Tasmanian nativehen Tribonyx mortierii

Other moorhens have been described from older remains. Apart from the 1–2 extinctions in more recent times, another 1–4 species have become extinct as a consequence of early human settlement; a species close to the Samoan moorhen from Buka, the Solomon Islands, which is almost certainly distinct from the Makira moorhen, as the latter cannot fly. The undescribed Viti Levu gallinule of Fiji would either be separated in Pareudiastes if that genus is considered valid, or it may be a completely new genus. Similarly, the undescribed "swamphen" of Mangaia, currently tentatively assigned to Porphyrio, may belong to Gallinula or Pareudiastes if that genus is considered valid.

Evolution

thumb|upright|Badge of [[HMS Moorhen|HMS Moorhen]]

Still older fossils document the genus since the Late Oligocene onwards. The genus seems to have originated in the Southern Hemisphere, in the general region of Australia. By the Pliocene, it was probably distributed worldwide:

  • Gallinula sp. (Early Pliocene of Hungary and Germany)
  • Gallinula kansarum (Late Pliocene of Kansas, USA)
  • Gallinula balcanica (Late Pliocene of Varshets, Bulgaria).<!-- Ardeola51:91 -->
  • Gallinula gigantea (Early Pleistocene of the Czech Republic and Israel)

The ancient "Gallinula" disneyi (Late Oligocene&mdash;Early Miocene of Riversleigh, Australia) has been separated as genus Australlus.

References

  • Identification guide (PDF) by Javier Blasco-Zumeta