Sheep recognize familiar and unfamiliar human faces from two-dimensional images

Area of Science:

• Cognitive Science
• Animal Behavior
• Neuroscience

Background:

• Face recognition is a crucial social skill in humans.
• Sheep are social animals with known abilities to recognize conspecifics and familiar humans.
• Holistic face-processing abilities in sheep remain largely unexplored.

Purpose of the Study:

• To investigate the face-recognition capabilities of sheep (Ovis aries).
• To determine if sheep can recognize familiar faces presented from different perspectives.
• To compare sheep's face-processing abilities with those of humans and non-human primates.

Main Methods:

• Eight sheep were trained to recognize celebrity faces from photographic portraits.
• Performance was tested using frontal and tilted image perspectives.
• Sheep's ability to recognize a familiar handler from photographs was assessed without pretraining.

Main Results:

• Sheep successfully distinguished learned-familiar faces from unfamiliar ones above chance.
• Sheep recognized celebrity faces even when presented in tilted perspectives, with a performance drop similar to humans.
• Sheep identified a familiar handler in photographs with 71.8% accuracy without prior training.

Conclusions:

• Sheep possess advanced face-recognition abilities.
• Sheep demonstrate holistic face-processing, including recognition across different viewpoints.
• Sheep's face-recognition skills are comparable to those observed in humans and non-human primates.