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.
