The west coast of South Africa is part of the migratory corridor for humpback whales (Megaptera novaeangliae) sub-stock B1, and also a migratory and feeding area for sub-stock B2. So-called super-groups of the species (defined as 20+ individuals feeding close to each other, within five body lengths of their nearest neighbour) have been sighted yearly in the area since 2011. The Mammal Research Institute – Whale Unit, University of Pretoria, performed research boat-based activities in the area in two blocks of activities over the period of super-groups occurrence. The first block was from 16 November to 06 December 2024; the second, between 16 January and 02 February 2025. The latter focused in suction-cup tag deployments and was just partially covered with funds from the Whales and Climate Research Program. In total, 21 boat days were performed, summing ~ 107 h of activities at sea. During such effort, 31 groups of humpback whales were logged. From these, 13 were super-groups, with group sizes ranging from 20 to 80+ individuals. The other groups included unaccompanied adults or smaller groups of up to 30 dispersed individuals. We obtained 58 biopsy samples of humpback whales, fluke pictures of a minimum of 70 different individuals, drone footage from nine flights, 8 faecal samples, 26 zooplankton samples, and the deployment of nine suction-cup tags. The data and samples obtained will help in a better understanding of aspects such as stock structure, movements, diet, size and body condition, and sex of the humpback whale individuals forming the super-groups.
