Hi Cath, I've been puzzling over the pictures of these very nice ants and agree that they are likely not to be Rhytidoponera metallica. The red legs and overall look just seems too different. They may well be Rhytidoponera aspera (https://www.antwiki.org/wiki/Rhytidoponera_aspera) which have been found in the region, but which I haven't seen before. I'll keep a look out from now on! Cheers, Jon