Getting an earful
Ears are essential for getting useful information from the environment. Not just information about what is around us, but where and how we relate to it in space. For animals, ears may serve another function: communication.
The way an animal holds its ears, as well as the number of times it changes between one ear posture and another, can tell us something about how they’re feeling. This is useful when trying to understand our pet dog or cat. But, animals aren’t just telling us how they feel, they’re telling each other (we just happen to pick up on it as well). It would make sense for social animals to be able to communicate their emotions, particularly negative ones like pain or stress, in order to get help from their fellow group members.
Following that line of thinking, we might expect that an animal like sheep communicate with each other, possibly through ear posture. Sheep are a social animal and a prey species so they want to know what’s going on with their fellow sheep.
One experience that hasn’t been assessed up until now is pain. We looked at what ear postures lambs showed both before and after they were tail docked (a procedure known to cause pain). We saw that lambs spent less time with their ears in the passive posture and more time with their ears back after docking. They also moved their ears more (changed between different postures) after docking.
Getting back to the key idea of this post though: communication. It’s unlikely that holding their ears in a certain way or changing how often they move their ears helps lambs alleviate pain (like some other pain-related behaviours may do). Instead, lambs might use their ears to signal to other lambs or adult sheep that they’re in pain. The question then is: are other lambs or adults paying attention?
Reference: Guesgen, M.J., Beausoleil, N.J., Minot, E.O., Stewart, M., Stafford, K.J. (2014). Lambs show ear posture changes when experiencing pain. Animal Welfare (in preparation).