IUCN Red List Assessment
Red List Category Year Assessed
Vulnerable Red List Criteria
Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. Reviewer/s
Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority) Contributor/s Justification
The cause of the population reduction in this species (commercial whaling) is reversible, understood, and is not currently in operation. For this reason, the species is assessed under criterion A1, not under A2, A3 or A4. Physeter macrocephalus
is globally widespread (thus not qualifying as threatened under criterion B), and does not have a global population that warrants listing under criteria C-D. Empirical trend data for this species globally are unavailable. However, commercial whaling at a large scale for this species in the North Pacific and Antarctic within the last three generations (82 years) certainly resulted in a global decline during this period. Commercial whaling for this species has ceased and therefore this population is evaluated under the A1 criterion rather than under the A2-4 criteria. A peer-reviewed publication (Whitehead 2002) provides a model-based estimate of global trend that can be used to evaluate the population under the A1 criterion. The results from that study gave a 6% probability for Endangered, a 54% probability of meeting the Vulnerable category, and a 40% probability of falling into the Near Threatened category. The results suggest little chance that the population would meet the criteria for Endangered or for Least Concern. There is credible and realistic evidence for either the Vulnerable or Near Threatened category. Given that the results give greater probability for at least the Vulnerable category (60%), and that this is the more precautionary category, the species is classified as Vulnerable.