Habitat use of south-eastern Pacific humpback whales (

Abstract

Context Golfo Dulce is a wintering ground of the south-eastern Pacific population of humpback whales. Habitat use and spatial preferences of whales during their reproductive season must be addressed to effectively conserve this species. Aims This study aims to determine spatial segregation depending on humpback whale group composition (groups that included mother–calf dyads versus adult-only groups). Methods Spatial aggregation was assessed using sightings per unit of effort from June to October, 2010–2019. The group preferences were analysed as a function of water depth and distance from the coast, and habitat use was characterised using behavioural data. Key results Our SPUE analysis showed important locations used by humpback whales. The mother–calf groups were present in waters <80 m deep, and their main behaviour was resting (nursing and social). Adult-only groups were in the deeper waters, and the main behaviours were social breaching and travelling. Spatial preferences and behaviour data allowed the identification of critical nursing areas near potential mating grounds. Conclusions and implications Our study has highlighted the need for inshore habitat protection, and these habitat-use patterns should be considered when designing effective conservation and management strategies for marine spatial planning.