Causes of adult mortality in two populations of New Zealand sea lions (Phocarctos hookeri)

Infectious disease, particularly tuberculosis caused by Mycobacterium pinnipedii, and conspecific trauma are the leading causes of adult mortality in New Zealand sea lions (Phocarctos hookeri), an endangered species endemic to New Zealand. The study, which analyzed 136 sea lions across two populations—one on remote Enderby Island and another recolonizing the mainland—revealed that these factors accounted for 37% and 24% of diagnosed deaths, respectively. Anthropogenic trauma emerged as a significant threat in the mainland population, highlighting the growing risk from human interactions as both human and pinniped populations expand. This research underscores the critical need to manage human-pinniped conflicts to ensure the species' recovery.

Lenting, B., Gartrell, B., Kokosinska, A., Duignan, P. J., Michael, S., Hunter, S., & Roe, W. D. (2019). Causes of adult mortality in two populations of New Zealand sea lions (Phocarctos hookeri). Veterinary and Animal Science, 7, 100057. https://doi.org/10.1016/j.vas.2019.100057