02 August 2015

Racial identity of Purple Swamphens from DNA - Sabkhat Al Fasl


Steve Trewick, an expert on the Purple Swamphen group who has written a number of papers of the species, very kindly analised some DNA from two dropped Purple Swamphen feathers I sent him from two birds we trapped and ringed at Sabkhat Al Fasl, Saudi Arabia. Steve sequenced a New Zealand bird at the same time as a control for the Saudi Arabian birds. The idea was to try to ascertain the subspecies involved in the birds occurring in Saudi Arabia. Steve said the following “As expected the birds appear to fall with the poliocephalus samples we have”. I then asked Steve if he knew if the DNA from my bird was from P. p. poliocephalus or from P. p. caspius or P. p. seistanicus. These are all grey-headed types like our birds. Steve replied saying “That’s the problem at the moment there are simply not enough data for all populations for comparison. I’m working on getting additional sampling that will help answer your question”. The good news is that even with a few, and very small, feathers we can get some good data. We still need to search for better tissue so that other markers can be used too. The problem with mitochondrial DNA that includes Control Region is it is maternally inherited so if there is inter-racial mating then we will get confused but the more data we have the less chance of this occurring.