The Collaborative International Dictionary
Chief hare
Chief hare \Chief" hare`\ (Zo["o]l.) A small rodent ( Lagamys princeps) inhabiting the summits of the Rocky Mountains; -- also called crying hare, calling hare, cony, American pika, and little chief hare.
Note: It is not a true hare or rabbit, but belongs to the curious family Lagomyid[ae].
Wiktionary
chief hare
n. A small rodent, the pika.