DEVELOPMENT OF SOCIAL-BEHAVIOR IN 4 LITTERS OF DOGS (CANIS-FAMILIARIS)

The development of social behaviour in 4 litters of dogs was observed without interfering with the puppies from birth to 8 weeks of age. Dir ect and continuous observation was combined with video recording. Thre e of the litters were observed during one session of 2 h once a week, and the fourth litter during one session of 40 min twice a week. Socia l interactions were divided into 1) investigation of litter mates (lic king, sniffing or investigating orally), 2) social play, 3) and intera ctions in which agonistic elements (dominance postures, threats, bites or submission) were displayed. The different forms of social interact ions appeared for the first time when the puppies were between 14 and 21 days of age. Social investigation appeared first and was followed b y play and agonistic interactions. From week 5, differences between th e puppies in the tendency to initiate social play and agonistic intera ctions emerged. Generally, within the litters individual differences w ere consistent over weeks 6-8 (positive correlations between weeks), w hereas the tendency in the puppies during these weeks were negatively correlated with those of week 3 (play) or weeks 3 and 4 (agonistic int eractions), indicating a rebound effect for both play and agonistic be haviour. No significant correlations, however, were found for social i nvestigation. More often than expected males played or engaged in agon istic with other males, whereas these behaviours occurred less often t han expected between females. Both males and females, however, preferr ed male partners for agonistic interactions. No sex differences were f ound in the direction of social investigation. Agonistic behaviour was often responded to by play and play was often responded to by agonist ic behaviour, and the results indicated that before 8 weeks of age dif ferences in social behaviour between the puppies were already establis hed.