First Direct Evidence for Natal Wintering Ground Fidelity and Estimate of Juvenile Survival in the New Zealand Southern Right Whale Eubalaena australis

A groundbreaking study provides the first direct evidence of natal wintering ground fidelity and estimates juvenile survival rates in New Zealand's southern right whale population. Researchers used DNA profiling of skin biopsy samples to track individual whales from their year of birth, documenting their return to the Subantarctic Auckland Islands over multiple years. Fifteen out of 57 whales initially sampled were recaptured during winter surveys between 1995-2009, including four individuals aged 9 to 11 years, with two females first identified as calves in 1998 and later seen with their own calves in 2007. The study estimates high annual juvenile survival rates ranging from 0.87 to 0.95, using Cormack-Jolly-Seber models to analyze discrete age classes and continuous age functions. This method offers a robust approach for long-term demographic and genetic monitoring, particularly useful for species like southern right whales that undergo significant physical changes over time.

Carroll, E. L., Fewster, R. M., Childerhouse, S. J., Patenaude, N. J., Boren, L., & Baker, C. S. (2016). First Direct Evidence for Natal Wintering Ground Fidelity and Estimate of Juvenile Survival in the New Zealand Southern Right Whale Eubalaena australis. Plos One, 11(1), e0146590. https://doi.org/10.1371/journal.pone.0146590