08 April 2013

Range expansion of Purple Swamphen in Saudi Arabia

The Purple Swamphen Porphyrio porphyria is a common resident breeder at Sabkhat Al Fasl and has recently (2011) expanded its breeding range to Khafrah Marsh a wetland site 30 kilometres south-west of Sabkhat. The species favoured habitat is large Phragmites australis reed-beds with associated water which is available at all the sites the species has been seen at in Saudi Arabia. The range expansion appears to be quite a quick as the first record for Saudi Arabia was on 8th August 2003 at Sabkhat Al Fasl core area 2 (Meadows 2004). Breeding was confirmed at this site in 2007 (Jennings 2010) with numbers increasing each year since this date. A new breeding site for the species was found in August 2011 at Khafrah Marsh where six adults and a juvenile were seen. This site is located 30 kilometres south-west of Sabkhat Al Fasl. Other signs of the species expanding its range include a record from Dhahran percolation pond, 130 kilometres to the south of Sabkhat Al Fasl in October 2009 and a recent sighting of one and possible two birds at Ash Shargiyah Development Company Farm, Fadhili 31st January 2013. Ash Shargiyah Development Company Farm is located approximately 40 kilometres due west of Sabkhat Al Fasl and although in the desert has an area of Phragmites australis reed-beds in which the bird was located. It appears that the rapid population increase observed at Sabkhat al Fasl over the past five years has created pressures on territories and prompted some birds to move to alternative suitable habitats within the Eastern Province and thereby expand its range. The single bird seen in Dhahran in October 2009 may well have been an early sign of this process (Roberts & Babbington 2012). Another alternative is the addition pressure being exerted on Sabkhat Al Fasl from hunters shooting birds, including Purple Swamphens and numerous fishermen catching the local Talapia fish with nets has cause some birds to move to find less disturbed areas to live and breed? The Purple Swamphen that occurs in Saudi Arabia is of one of the grey headed eastern / Asian subspecies from the Porphyrio porphyrio poliocephalus group which are either Porphyrio porphyrio caspius or Porphyrio porphyrio seistanicus. P. p. poliocephalus is found from India and Sri Lanka to south China and north Thailand. It has cerulean blue scapulars, face throat and breast. P. p. caspius is from the Caspian Sea area, and is like P.p. poliocephalus, but is larger whereas P. p. seistanicus occurs from Iraq to Pakistan, and is like P.p. poliocephalus, but larger although smaller than P.p caspius. A number of birds have been identified as P. p. seistanicus in Kuwait, UAE and Qatar but unless a bird is captured and measurements taken it is best, in my opinion, to leave these birds as either P. p. seistanicus or P. p. caspius.

Meadows, B.S., 2004. The first Purple Gallinule Porphyrio porphyrio in Saudi Arabia, Sandgrouse 26: 153.
Jennings M.C. 2010. Alas of the breeding birds of Arabia. Fauna of Arabia 25.
Roberts & Babbington 2012. Status and range expansion of Purple Swamphen in eastern Saudi Arabia Sandgrouse 34