Moerman versus Pierson: the nexus of occupancy in animals ferae naturae and liability in tort

Pierson v Post is a well-known early case on establishing a property interest in an animal ferae naturae, i.e. in a wild animal. Pierson established an early American interpretation of the rule of occupancy for animals ferae naturae. This article provides a complete review of that case and provides details and original language quotations from Pufendorf, Grotius, Fleta, Bracton, Barbeyrac, Blackstone, and the Roman laws discussed in the case. There is extensive discussion on the Codes and Institutes of Justinian from the Corpus Juris Civilis. The article covers the historical development of the idea of occupancy as related to animals ferae naturae. This analysis is then used to contrast the decision in Moerman v. State of California.

In Moerman v. State of California, a California appellate court found the state was not liable for damages caused by wild elk involved with a state-guided relocation program. In so doing, the court relied upon a narrow and alternative interpretation of Pierson v. Post’s long-established precedence on the rules of occupancy for animals ferae naturae.

This article attempts to illuminate the differences between the appellate court’s interpretation and previous interpretations of those rules. The issues of focus are when can a person acquire an animal ferae naturae, and if acquired, can that person then be held liable for the injuries caused by that wildlife? In particular, these issues were encountered in Moerman and this article reviews the decision of that case and finds it at odds with traditional jurisprudence.

This paper finds a clear tradition in common law on when persons can acquire an animal ferae naturae and also finds that such an owner can in some cases be held liable for the tortious acts of that animal. This paper finds that Moerman’s handling of the rule was too narrow and thus incorrectly applied. Had the rule been correctly applied, it is found that the state might have reasonably been found liable for property damage.