Variation in faecal testosterone levels in male gray whales on a foraging ground relative to maturity and timing.

ABSTRACT: Understanding wildlife reproductive seasonality is crucial for effective management and long-term monitoring of species. This study investigates the seasonal variability of testosterone in male Pacific Coast Feeding Group (PCFG) gray whales, using an eight-year dataset (2016-2023) of individual sightings, drone-based photogrammetry and endocrine analysis of faecal samples. We analyzed the relationship between faecal testosterone levels and total body length (TL), body condition (body area index, BAI), sexual maturity and day of the year using generalized additive mixed models. Our findings reveal a significant increase in faecal testosterone levels in mature males (MM) towards the end of the foraging season. This increase was not observed in JM, highlighting age-dependent development of se

SUBMITTER: Fernandez Ajo A 

PROVIDER: S-EPMC11744369 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature