The bowing display of Streptopelia doves was studied in captive individuals of five species at Madingley, Cambridge, England from 1961 to 1964. The five species were S. roseogrisea-(risoria) (barbary), S. decaocto (collared), S. turtur (turtle), S. chinensis (necklace) and S. senegalensis (senegal). F1 hybrids were bred between the barbary and the other four species and single males of each of the F1 necklace x collared and senegal x turtle were also observed. F2 generation birds of the collared x barbary F1 hybrid, as well as some backcrossed birds were included in the study. Bowing displays were usually given only by male doves when close to another dove. The form of the bowing display differed from species to species and exhibited a typical intensity in each species. Each hybrid also had a bowing display of characteristic form. The ciné film showed that there was variation in form between the bowing cycles of any one bout, both in the pure species and in the hybrids. This variation could not be adequately described from the films taken in this study. The rate of bowing of each species was constant and differed from that of every other species. Hybrids also exhibited a typical intensity in this character. There was much more intra-specific and intra-hybrid variaton in the timing of individual movements within bowing cycles in a bout than in the timing of the bowing cycle as a whole. The relative variability of the different elements could be ranked, and in all species and hybrids studied the timing of the total cycle tended to be least variable and that of the pause at the top of the bow most variable. The frequencies with which bowing displays and kah calls were given under standard conditions, were measured, and provided two other behavioural characters whose pattern of inheritance could be studied. Three patterns of inheritance were found in each of these behaviour patterns of the F1 hybrids. In some cases the behaviour was intermediate between that of the two parents, in others it approximated the behaviour of one parent closely and in others again the hybrid's behaviour exceeded the range of either parent.