On 12 May 2016, Janske van de Crommenacker photographed a Greater Crested Tern at Denis Island, bearing a metal ring and yellow colour ring. There is no ringing programme for this species in Seychelles, suggesting that this bird must have come from elsewhere. After making enquiries, it appears that almost certainly the bird originated from South Africa.
Nola Parsons from SANCCOB, a seabird rescue centre based at Cape Town responded on 22 July to say "I think it is very possible that we rung the bird at SANCCOB! Although we normally place the metal ring on the right leg, but it could have been placed on the left leg by mistake, and we did use yellow bands that looked very similar to those in the photo. Without knowing the number, we can’t say for sure but the yellow bands were put on chicks that were hand-reared (mostly collected from the Cape Town waterfront area) and released, either on Robben Island or back at the waterfront. So it is really nice for us to know, or at least hope, that our chicks are making it to adulthood although I am not sure that they are meant to travel all the way to the Seychelles!"
It is known that Greater Crested Terns from outside the Malagasy region visit Seychelles. SBRC has recorded three records of the dark-backed race velox, which breeds from the Red Sea to Persian Gulf and Bay of Bengal.
It has also been noted that the species is a fairly common non-breeding visitor to almost all Seychelles coasts yet the total national breeding population is only a few hundred pairs. Perhaps numbers are augmented by non-breeding visitors from both the north and the south?