Wild ungulates can recognize certain predators without previous experience, but this innate ability may be relaxed under domestication. Using naïve dairy calves, Bos taurus, we examined the effects of exposure to a predator odour (coyote, Canis latrans, urine) and two control odours (deer urine and water) on (1) latency to approach a milk food reward, (2) exploration, vigilance and locomotor play, (3) magnitude of the startle response to a sudden noise delivered upon arrival at the feeder and (4) heart rate during feeding in 10 min trials on three consecutive days. In response to predator odour, calves delayed feeding and tended to explore more and play less in the first 30 s of the trial compared to calves exposed to control odours. The duration spent feeding and standing with the head raised (i.e. vigilant) did not differ among treatments. On the first day, calves exposed to predator odour startled more to a sudden noise than control animals. Mean heart rate during feeding decreased across days in the control treatments, but not in the predator treatment, suggesting a sustained response to the predator odour. We conclude that naïve domestic calves retain the ability to distinguish between predator and nonpredator odour.

Data were collected from the University of California Davis Dairy Facility on 34 calves in 2015. Variables are defined in Sheet 2 of the Excel file. The R script used to analyze the dataset is provided.