Pierson v. Post: Who Owns the Fox?

Post was hunting a fox on a wild, uninhabited beach. He was in active pursuit — his dogs were chasing it. Pierson, knowing Post was chasing the fox, intercepted and killed it. Post sued, claiming the fox was “his” because he was pursuing it first.

The court ruled for Pierson. Mere pursuit — even hot pursuit — does not establish possession. Property in wild animals is acquired only by actual capture or mortal wounding. Post was chasing the fox, but he never possessed it. The first person to actually capture or kill the animal owns it, regardless of who started the chase.

The dissent argued that among hunters, custom recognized that pursuit was enough to establish a claim. Requiring physical capture would discourage hunting and reward interlopers. This dissent raises a broader question: should courts defer to industry customs or impose formal legal rules?

Pierson v. Post is typically the first case in Property class because it introduces foundational concepts: What does it mean to “own” something? How do we establish property rights in unowned things? Should rules be bright-line (easy to apply but sometimes unfair) or flexible (fairer but harder to predict)? These questions recur throughout all of property law — and all of law.