The bone is mine!—context-specific vocalization in dogs

Abstract

olfactory perception in dogs and the recent suggestion of olfactory learning in canine fetuses, we believe it is likely that very young puppies detect socially important stimuli using this chemical sense. We examined the ability for discrimination of social odors of 1-week-old dog puppies using a simple preferential positioning method. We tested 8 puppies of 2 litters (miniature dachshunds and miniature schnauzers). The dachshunds were 7 days old and the schnauzers were 8 days old. We prepared handkerchiefs with their mother’s neck odor and with the odor of unfamiliar nonmother adult females of the same breed with the same coat type and color. The puppies were placed between the 2 handkerchiefs in a cardboard box and were allowed to crawl freely in the box. The placement of the handkerchief was counterbalanced by switching their positions after 30 sec and 90 sec during the 120-sec trial. We analyzed the length of time the puppies stayed in each side and the length of time they touched the handkerchief with their nostrils. A repeated-measures ANOVA of breed (2) ! odor (2) and length of stay near the handkerchief did not show significant effects, however, the duration of nostril touch showed a clear main effect of odors (F(1,6) 5 14.749, P 5 0.009). The puppies touched the handkerchief with the mother’s odor for a much longer time than those with the odor of unfamiliar females. There was also a trend for the dachshunds to keep touching the handkerchief for a longer duration (F(1,6) 5 4.666, P 5 0.074). However, interaction of the 2 factors was not significant. The puppies preferentially stayed with the mother’s odor for a significantly longer time period. This suggests that the ability for olfactory discrimination of biologically important stimuli may be well developed before the puppies open their eyes. Whether this shows a recognition of the mother as an individual or a general recognition of motherlike odors must be addressed in the future.