During the May 2009 Namibian ringers' gettogether at Farm Wiese near Rehoboth, ringers assisted Dirk Heinrich with what I believe was the third iteration of the ringing project he had initiated with Dieter Oschadleus to study the movements between colonies of sociable weavers. While on the first occasion birds were fitted with metal rings only, on the second occasion colour rings were also added, using a single colour which applied to a particular colony - in order to track whether there is any movement between nests. I was lucky enough to participate in the 2009 get-together and naturally helped with the ringing of the sociable weavers. I understand that it was only on a subsequent retrapping at one of the nests later in 2009 that any evidence was found of a bird caught at one colony having "defected" to another colony.