SPECIES

Purple Gallinule Porphyrio martinica

Richard L. West and Gene K. Hess
Version: 1.0 — Published March 4, 2020
Text last updated January 1, 2002

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Identification

Medium-sized marsh hen; total adult length 27–36 cm, mass 208–288 g. In adult, head, neck, and most underparts glossy purple, with olive-green upperparts, white undertail coverts, red bill with yellow tip and blue-white frontal shield (at juncture of bill and forehead), and yellowish legs and feet. Toes long (middle toe and claw 7–8 cm). Sexes alike in plumage and overlap in size; female mass about 10% less than male (Hunter 1986).

Eyes dark brown; bill, frontal plate, tarsi, and toes pale gray-green. Downy young black.

Similar Species

In North America, Common Moorhen (Gallinula chloropus) somewhat similar in appearance, but adult Purple Gallinule has head and underparts purple versus blackish in moorhen, and frontal shield pale blue versus red in moorhen. Moorhen also has prominent white border along sides and flanks, which is lacking in Purple Gallinule, and undertail coverts black with white border (these entirely white in gallinule). Purple Gallinule about the same size as Common Moorhen but more slender, with longer neck and legs, giving it a different aspect; it stands higher, with legs placed more forward than the Common Moorhen (Gosse and Hill 1847). Juvenile Purple Gallinule distinguished from juvenile Common Moorhen by paler and browner overall coloration, with light-brown breast and whitish belly, while juvenile moorhen is grayer with grayish breast and belly and a pale border along sides and flanks absent in juvenile gallinule.

Juvenile American Coot (Fulica americana) distinguished from juvenile Purple Gallinule by overall grayish coloration, dark (not white) undertail coverts, and dark (not yellow) legs and feet. Juvenile Purple Gallinule superficially resembles even paler Azure Gallinule (P. flavirostris), with which it overlaps in its South American range, but juvenile Purple Gallinule has olive green in its back and blue-green in primaries rather than pale blue-gray and azure tones of Azure Gallinule.

Not to be confused with superficially similar but much larger Purple Swamphen (Porphyrio porphyrio), also known as Purple Gallinule, which has become feral in s. Florida and is widespread outside the Americas (Cramp and Simmons 1980a, American Ornithologists' Union 1998a, Pranty et al. 2000).

Molts

Hatchlings

Covered in glossy-black natal down with varying amounts of dull frosty white (feather sheath) on chin, throat, face, crown, and secondary coverts. Pollex (wing claw) present. Gross and Van Tyne (Gross and Van Tyne 1929: 442) give the following soft part colors “. . . iris, chaetura drab; tarsus, vinaceous-drab; feet light russet-vinaceous; claws mouse gray; claw at tip of manus, white. . . base of maxilla, eugenia red extending forward to an irregular black line which runs through the nostril, bordering this black line in front is a band of pale livid pink, the remainder of the maxilla distal to the latter band is black except the chalky white egg tooth at the tip. The tip of the mandible (lower) is black, the base flesh pink with a narrow black band and one of hydrangea pink just posterior to the black of the distal end of the lower mandible.”

Juvenile Plumage

Prejuvenile (postnatal) molt complete. Begins at 2.5–3 wk on breast area of ventral tract (Helm 1982). Alar, cural, dorsal, and spinal tracts emerging at 3–4 wk (Helm 1982). Full Juvenile plumage attained by 10 wk (Helm 1982).

Forehead, crown, hindneck, back, scapulars, and upperwing coverts dark olive brown; hindneck often washed olive green, upper back, scapulars, and upperwing coverts tinged with bronze-green, and upperwing coverts variably tipped paler (buff). Lower back dark olive brown, and rump through tail dark brownish, with rectrices edged paler. Sides of head paler than crown (buff brown); chin and throat even paler (cream to whitish). Breast and remaining underparts (except undertail coverts) buff brown, becoming more grayish on breast, more olive on flanks and thighs, and palest (whitish) on rear flanks, belly, and vent. Under tail-coverts white. Some individuals, presumably yearlings, have brownish tinge to some back- and flight feathers. Juvenile brown with olive-green back; light-tan sides, breast, and belly; and white undertail coverts. Wings olive-brown with blue-green primary coverts. Outer webs of primaries and secondaries olive-brown with dull-olive gloss that appears greenish blue at some angles, inner webs dull charcoal brown; tertials dark olive brown. Under surface of primaries, secondaries, and tertials dull gray; most underwing coverts pale brown gray broadly margined white (Gross and Van Tyne 1929, Taylor 1998, GKH).

Soft parts: “. . . iris sayal brown; bill grape green shading to vinaceous-drab at the base; frontal plate, neutral gray; tarsus, dark olive-buff; toes, olive-ochre; nails olive-buff” (Gross and Van Tyne 1929: 443).

Basic I Plumage

Prebasic I (Postjuvenile) molt apparently complete; begins at about 16–20 wk and lasts 4–5 mo (Hunter 1986). Molt starts on upperparts and sides of body, followed by sides of head, breast, flanks, and upperwing coverts, then underparts, underwing coverts, remiges, and rectrices. White on throat and chin and some flecks of brown on crown, neck, and face are last areas to molt. In migratory populations, body feathers replaced on winter grounds late Sep–Mar, but nonmigratory populations in Suriname replace body feathers Jul–Nov and flight feathers Oct–Nov (Cramp and Simmons 1980a, Helm 1994).

Basic I plumage similar to, and often not separable from Definitive Basic (adult) plumage if no worn Juvenile feathers present. Some individuals may have feathers of upperparts with pale buff or gray tips, and upperparts may be slightly more rufous brown than adult (Cramp and Simmons 1980a, Taylor 1998).

Definitive Basic Plumage

Definitive Prebasic (Postnuptial) molt complete. In migratory populations molt occurs late summer preceding southern migration (Helm 1982). Molt usually starts with a few small body feathers, followed by remiges and tail. Remiges and rectrices lost simultaneously, resulting in flightless period of 3–4 wk (Hunter 1986, Helm 1994). Heavy molt on body and wing coverts when flight feathers fully grown. In Louisiana, entire molt took 6 wk and occurred mainly Aug–Sep (Helm 1994). Molt recorded Jun–Oct in non-migratory populations in Suriname (Cramp and Simmons 1980a, Helm 1994).

In Ohio, flightless Purple Gallinules recorded 15 Aug–10 Sep; 1 flightless adult taken 4 Sep had no remex longer than 18 mm, and some were entirely sheathed; flightless adult taken 10 Sep had no remex longer than 75 mm, and basal halves of most of remiges were sheathed. Birds observed or taken after 15 Oct have fully developed remiges, the longest being >125 mm; these birds could fly well (Trautman and Glines 1964). An adult flightless Purple Gallinule shot during hunting season on 5 Oct 1978 was the latest molting individual found in Louisiana (Helm 1982).

Entire plumage becomes drab and faded by time of Prebasic molt (Helm 1994). At the approximate time remiges are shed, bill becomes dry and scaly and loses its swollen appearance. Bill and frontal shield also become dark brown (Helm 1994), or shield may become pale blue and bill tip yellow-green during molt (Cramp and Simmons 1980a).

After completion of molt, Definitive Basic plumage similar to Definitive Alternate plumage. In fresh plumage, feathers of underparts narrowly tipped white.

Definitive Alternate Plumage

Definitive Prealternate (Prenuptial) molt partial, probably involves smaller body feathers (Cramp and Simmons 1980a).

Head, front, and sides of neck, and all underparts (except undertail coverts), mainly deep, glossy, bluish purple, becoming more blackish along base of bill and frontal shield, and dull blackish on lower belly, vent, and thighs. Under tail-coverts white. Hindneck, sides of back, and sides of breast pale blue, often washed green. Remainder of back, scapulars, rump through tail, inner greater and median upperwing coverts, and tertials, olive brown to olive green, but variable; back iridescent and sometimes more bluish, scapulars and rump sometimes brownish, upperwing coverts sometimes purer green, and tail toward iridescent olive-blue. Lesser upperwing coverts, outer median and greater wing coverts, outer webs of remiges and primary coverts, pale blue, with olive green wash on inner primaries (P1–P6 or P7), and near central median and greater wing coverts. Inner webs of remiges and primary coverts dark grayish brown. Axillaries and larger underwing coverts dark brown or gray brown, washed bronze or bluish, especially on outer webs, and larger underwing coverts sometimes narrowly tipped white. Smaller underwing coverts pale blue or blue green. Under surface of remiges and rectrices dull gray (Taylor 1998).

Bare parts: “Iris, Hay's russet; the distal 122 mm of the bill, light virdine yellow; base of bill, jasper red; frontal plate, light forget-me-not blue; tarsus and feet amber yellow; claws naples yellow” (Gross and Van Tyne 1929: 444). Color of iris, legs and feet become duller outside of breeding season (Taylor 1998).

In worn plumage, upperparts become darker blue-green and olive wash lost except on scapulars and tertials, and underparts become less glossy and more grayish (Taylor 1998).

Bare Parts

See Molts and plumages, above. Also see Belton 1984 .

Measurements

Linear Measurements

Males average larger than females in all measurements (see Appendix 1) South American males average larger than North and Central American males in all measurements. Females of all 3 regions are similar in size.

Mass

Mean (g) of 4 adult males taken in Panama: 230.1 (range 203.7–269.0); adult female, 190.3; juvenile male, 218.4; juvenile female, 141.7 (Gross and Van Tyne 1929). Individuals taken from a Colombian rice field during early nesting season: mean (g) for males 213.4 ± 5.1 SE, females 223.5 ± 15.6 SE; not significantly different (n = 14 males and 14 females; McKary McKay 1980). No information available on geographic variation.

Enlarge
Juvenile Purple Gallinule

; photographer William L. Newton

Enlarge
Purple Gallinule, adult perched

Note long toes, adaptations for walking on floating vegetation; photographer William L. Newton

Enlarge
Purple Gallinule, adult swimming

; photographer William L. Newton

Recommended Citation

West, R. L. and G. K. Hess (2020). Purple Gallinule (Porphyrio martinica), version 1.0. In Birds of the World (A. F. Poole and F. B. Gill, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.purgal2.01