Great Frigatebird females

I have been contacted by a mate who works out on the reef about the identification of Great Frigatebird females, or more specifically their eye ring. He photographed a number of them recently in Far North Queensland and noted that the eye ring was blue-grey not the pink-red shown in field guides. I did some checking which produced the following: * HANZAB says the “eye ring is pink”, it quotes Hindwood, 1963 for the bill colour of Coral Sea birds but there is no reference for the eye ring colour. I think that volume of HANZAB was published in 1990. * Serventy, Serventy and Warham (1971) says the female eye ring is “black to mid blue”. So nearly half a century ago the species was generally considered to have blue eye rings in females but not now they are pink. * Pizzey says the eye ring is “blue in the Herald Cays, ne. Q (F.T.H.Smith))”. I have not yet tracked down what paper or article Graham got the reference from. * David James writing in BirdingASIA in 2004 comments under a photograph “On the female, .. blue orbital ring (latter diagnostic of South Pacific populations). Herald Cays, Coral Sea, June 1997.” Note he describes them as being diagnostic of South Pacific populations. * I checked all the other field guides I have Morcombe, Pizzey, Simpson and Slater in Australia and Newman in RSA have the ring as red-pink. What do other listers think? Chris Lloyd