Spatio‐Temporal Patterns in Relative Abundance and Distribution of Southern Right Whales in Southwestern Australia, 2021–2024

ABSTRACT Southern right whales ( Eubalaena australis ) are listed as Endangered in Australia due to past commercial exploitation. Currently, they are experiencing contemporary declines in population growth rates. Knowledge of critical periods and habitats in whale occupancy and reproduction is crucial for conservation efforts. This study documented the inter‐ and intra‐annual relative abundance and distribution of southern right whales within a Biologically Important Area along 450 km of southern coastline in Western Australia, using data from 94 weekly aerial surveys conducted from May–November 2021–2024. A total of 5899 individual sightings were recorded, of which 72% were mother–calf pairs. Whales were present from late‐May to early‐November, and peak relative abundance occurred in mid–late August. Maximum relative abundance varied annually, ranging from 92 to 194 individuals. Peak relative abundance periods and counts generally agreed with annual census observations for mother–calf pairs. Whale counts in the study area accounted for approximately 22% of the overall western population. Mother–calf pairs and unaccompanied whales occupied four key aggregation areas: Cheynes Beach, Cheyne Bay, Wray Bay, and Doubtful Island Bay. These findings highlight the seasonal significance of reproductive areas for southern right whales in southwestern Australia and are imperative for informing national recovery planning for the species.