Discriminative responsiveness by lambs to visual images of conspecifics

A series of experiments was conducted to assess whether lambs are discriminatively responsive to visual images of conspecifics. Lambs (3-4-week-old) consistently responded with more interest and less avoidance when exposed to a life-like image of an unfamiliar lamb, a ewe or the silhouette of a ewe, than to a meaningless mosaic of the same conspecific stimulus. In each instance, lambs preferentially sniffed the head region of the conspecific image. Slides of a ewe and a dog likewise elicited differential responses by lambs, but there were no clear differences in their attraction to, or avoidance of these two categories of stimuli. In contrast, adult ewes responded more negatively to the dog image than to the ewe slide. Overall, lambs appeared to respond to conspecific images as social stimuli, however, social discrimination by visual cues alone may improve with age and experience.