I originally put all these down as crested terns but a friend has cast doubt on them as being lesser crested. 1, 2, 3 were taken in Western Australia, 4 was in Fiji and 5 was taken out on the great barrier reef. The only one that I'm pretty sure of now is #5 as it's size compared to the black-naped terns makes it a crested tern. Any thoughts? Thanks in advance for any help received.