KQED just posted the segment devoted to Mikel’s research.

Our department is well known for its studies of emotion in humans. But Ph.D. candidate Mikel Delgado recently published the first experimental study in a wild animal on the emotion of frustration, using the Berkeley campus fox squirrels. As just as Prof. Dacher Keltner scores emotional responses in humans using the movement of facial muscles, Mikel scored emotion in squirrels by encoding the movements of their expressive bushy tails. The dog in this clip is Lucia’s dog, Gilly, demonstrating her keen interest in the lab’s research…
Delgado, M. M., & Jacobs, L. F. (2016). Inaccessibility of reinforcement increases persistence and signaling behavior in the fox squirrel (Sciurus niger). Journal of Comparative Psychology, 130(2), 128–137. http://doi.org/10.1037/com0000021