I have now discovered more about the background of this group. The adult pair came with several others from Hanover, which I did know, but was unaware that the adult male 'Sputnik' (in photo) is the father of the adult male' Yengo' (born while they were still living in Hanover) in the only other UK group, at Paignton. The two groups both contain closely related individuals e.g the mother of this male also lives in the Paignton group, so their male is her grandson, while another female in Paignton's current group was born at Colchester and is their male's sister.