Coital Behavior in Dogs Iii. Effects of Early Isolation On Mating in Males

Abstract

Three groups of male beagles were reared from weaning to sexual maturity under special circumstances and their responses to estrous females were compared in a series of mating tests. Five dogs were reared under conditions of semi-isolation (SI). They lived in individual cages and had very little physical contact with other animals throughout the experiment. The 5 males constituting the control group also inhabited individual cages but for 15 min. each day they were set free in the colony room where they could interact with other uncaged dogs. A final group of 5 males was reared together with 5 females in a I-acre field. None of the subjects had contact with estrous bitches except during the mating tests. The copulatory performance of the control and the group-reared males was essentially the same, but that of the semi-isolates was deficient in one particular. SI males mounted estrous females as readily and as frequently as members of the other 2 groups, but the orientation of mounting was abnormal. Ninety-seven per cent of the mounts by control and group-reared males were oriented to the female's rear, whereas 39 per cent of the mounts by SI dogs were directed to the head, side, or flank of the receptive bitch. One consequence of this difference was that SI males achieved intromission in only 24 per cent of their tests, as compared with 58 per cent and 54 per cent for the control and group-reared animals.