Gray-headed Swamphen Porphyrio poliocephalus Scientific name definitions

A large, colorful rail with dark purple to blue colors and a large red bill and frontal shield, the Gray-headed Swamphen is a recent addition to the avifauna of North America due to the establishment of a nonnative population in southeastern Florida. Although recently known as the Purple Swamphen (Porphyrio porphyrio), the taxonomy of this species is complex and various taxonomic bodies now split the P. porphyrio complex into 6 species, including the Gray-headed Swamphen (P. poliocephalus). For further information on the taxonomy of Porphyrio, see Systematics.

The native range of the Gray-headed Swamphen extends from the Middle East through India and southern Asia to northern Thailand. In 1996, this swamphen was discovered in Florida at Pembroke Pines in Broward County, the result of unintended releases from one or two private collections nearby. The following decade saw the Gray-headed Swamphen expand its range within Southeast Florida, including the Everglades, the Everglades Agricultural Area, and Lake Okeechobee, with dispersers found outside this region. From October 2006 through December 2008, an eradication program by state agencies removed 3,187 swamphens (Hardin et al. 2011 Hardin, S., E. Donlan, M. Ward and D. Eggeman. (2011). Attempted eradication of Porphyrio porphyrio Linnaeus in the Florida Everglades. Management of Biological Invasions 2 (1):47-55. Close ). However, the eradication campaign was deemed a failure at reducing the distribution and abundance of swamphens, and was discontinued. Since then, the Gray-headed Swamphen has continued to increase in the region and the species is now a common sight in stormwater treatment areas, water conservation areas, agricultural areas, and constructed wetlands in urban and suburban Southeast Florida. However, range expansion to date has mostly been limited to Southeast Florida.

The Gray-headed Swamphen has received little study in Florida (e.g., Pranty et al. 2000 Pranty, B., K. Schnitzius and H. W. Lovell. (2000). Discovery, origin, and current distribution of the Purple Swamphen (Porphyrio porphyrio) in Florida. Florida Field Naturalist 28:1-11. Close , Hardin et al. 2011 Hardin, S., E. Donlan, M. Ward and D. Eggeman. (2011). Attempted eradication of Porphyrio porphyrio Linnaeus in the Florida Everglades. Management of Biological Invasions 2 (1):47-55. Close , Pranty 2012 Pranty, B. (2012). Population growth, spread, and persistence of Purple Swamphens (Porphyrio porphyrio) in Florida. Florida Field Naturalist 40 (1):1-12. Close , Pranty 2013a Pranty, B. (2013a). Introducing the Purple Swamphen: Management, taxonomy, and natural history. Birding 45 (3):38-45. Close , Callaghan and Gawlik 2016 Callaghan, C. T. and D. E. Gawlik. (2016). Diet and selectivity of the Porphyrio porphyrio (Purple Swamphen) in Florida. Southeastern Naturalist. Close ). As a result, we incorporate into this account information on the Gray-headed and other closely related swamphens (Porphyrio) from the Old World (e.g., see Ripley 1977 Ripley, S. D. (1977). Rails of the World: A Monograph of the Family Rallidae. Godine, Boston, MA, USA. Close , Taylor 1996 Taylor, P. B. (1996). Family Rallidae (rails, gallinules, and coots). In Handbook of the Birds of the World. Volume 3: Hoatzins to Auks (J. del Hoyo, A. Elliott, and J. Sargatal, Editors). Lynx Edicions, Barcelona, Spain. pp. 108–209. Close , Taylor 1998 Taylor, B. (1998). Rails: A Guide to the Rails, Crakes, Gallinules and Coots of the World. Yale University Press, New Haven, Connecticut, USA. Close ). More detailed information was compiled for various sections of this account; e.g., habitat (Taylor 1996 Taylor, P. B. (1996). Family Rallidae (rails, gallinules, and coots). In Handbook of the Birds of the World. Volume 3: Hoatzins to Auks (J. del Hoyo, A. Elliott, and J. Sargatal, Editors). Lynx Edicions, Barcelona, Spain. pp. 108–209. Close , Freifeld et al. 2001 Freifeld, H. B., D. W. Steadman and J. K. Sailer. (2001). Landbirds on offshore islands in Samoa. Journal of Field Ornithology 72 (1):72-85. Close ), breeding (Craig 1980a Craig, J. L. (1980a). Breeding success of a communal gallinule. Behavioral Ecology and Sociobiology 6 (4):289-295. Close , Craig 1980b Craig, J. L. (1980b). Pair and group breeding behaviour of a communal gallinule, the Pukeko, Porphyrio porphyrio. Animal Behaviour 28 (MAY):593-603. Close , Jamieson and Craig 1987a Jamieson, I. G. and J. L. Craig. (1987a). Dominance and mating in a communal polygynandrous bird: Cooperation or indifference towards mating competitors? Ethology 75 (4):317-327. Close , Jamieson and Craig 1987b Jamieson, I. G. and J. L. Craig. (1987b). Male-male and female-female courtship and copulation behaviour in a communally breeding bird. Animal Behaviour 35 (4):1251-1253. Close , Jamieson 1997 Jamieson, I. G. (1997). Testing reproductive skew models in a communally breeding bird, the Pukeko, Porphyrio porphyrio. Proceedings of the Royal Society B-Biological Sciences 264 (1380):335-340. Close , Craig and Jamieson 1988 Craig, J. L. and I. G. Jamieson. (1988). Incestuous mating in a communal bird: A family affair. American Naturalist 131 (1):58-70. Close ), behavior (Holyoak 1970 Holyoak, D. T. (1970). The behaviour of captive Purple Gallinules (Porphyrio porphyrio). Avicultural Magazine 76:98-109. Close , Craig 1977 Craig, J. L. (1977). The behaviour of the Pukeko, Porphyrio porphyrio melanotus. New Zealand Journal of Zoology 4 (4):413-433. Close ), evolution (Garcia-R and Trewick 2015 Garcia-R, J. C., and S. A. Trewick (2015). Dispersal and speciation in Purple Swamphens (Rallidae: Porphyrio). The Auk: Ornithological Advances 132:140–155. Close ), and diet (Carroll 1966 Carroll, A. L. K. (1966). Food habits of Pukeko (Porphyrio melanotus Temminck). Notornis 13 (3):133-144. Close , Norman and Mumford 1985 Norman, F. I. and L. Mumford. (1985). Studies on the Purple Swamphen, Porphyrio porphyrio, in Victoria. Australian Wildlife Research 12 (2):263-278. Close ).

Although the Gray-headed Swamphen is predominantly sedentary within its native range, Porphyrio are known to disperse long distances (> 300 km) in response to unsuitable water levels (e.g., Vielliard 1973 Vielliard, J. (1973). The Purple Gallinule in the marismas of the Guadalquivir. British Birds 67 (6):230-236. Close , Sánchez-Lafuente et al. 2001 Sánchez-Lafuente, A. M., F. Valera, A. Godino and F. Muela. (2001). Natural and human-mediated factors in the recovery and subsequent expansion of the Purple Swamphen Porphyrio porphyrio L. (Rallidae) in the Iberian Peninsula. Biodiversity and Conservation 10 (6):851-867. Close ), and such dispersal has been documented in Florida (Pranty 2012 Pranty, B. (2012). Population growth, spread, and persistence of Purple Swamphens (Porphyrio porphyrio) in Florida. Florida Field Naturalist 40 (1):1-12. Close ). Their excellent dispersal ability combined with the abundance of an important food plant in Florida, the Gulf Coast spikerush (Eleocharis cellulosa; Pranty 2013a Pranty, B. (2013a). Introducing the Purple Swamphen: Management, taxonomy, and natural history. Birding 45 (3):38-45. Close , Callaghan and Gawlik 2016 Callaghan, C. T. and D. E. Gawlik. (2016). Diet and selectivity of the Porphyrio porphyrio (Purple Swamphen) in Florida. Southeastern Naturalist. Close ), has raised concern among wildlife managers about further expansion of the species. As a result, additional research on the potential impacts to native flora and fauna is badly needed.