Ant-ics and appetites: mapping ant (Formicidae) diversity and resource selection in Agumbe

Abstract

Ants are important components of terrestrial ecosystems, yet information on their diversity, behaviour, and resource use in non-protected landscapes of the Western Ghats remains limited. This study investigated ant diversity, community composition, behaviour, morphometrics, and resource selection across forest patches, grasslands, and areca plantations in the Agumbe landscape of the central Western Ghats. Field surveys were conducted between December 2025 and March 2026 using visual encounter surveys and active hand collection. Ant diversity, abundance, community composition, behaviour, and morphometric traits were documented. Resource selection experiments were conducted on Trichomyrmex colonies using sugar, rice, and seeds that differed in physical texture. A total of 75 ant species, 423 occurrence records, and 10,284 individuals were recorded. Forest patches supported the highest species richness, abundance, and diversity, while plantations and grasslands supported fewer species. Community composition differed significantly among habitat types, with habitat characteristics influencing ant assemblages more strongly than stream position. Behavioural observations documented a range of ecological roles, including predation, scavenging, honeydew collection, seed collection, brood transport, recruitment, and nest maintenance. The study also recorded ten putatively undescribed species, new state records, and worker polymorphism in Lepisiota wroughtonii. Resource selection experiments showed a clear preference hierarchy of Sugar > Rice > Seeds, indicating that resource characteristics might influence foraging decisions. The findings highlight the ecological and taxonomic importance of the Agumbe landscape and provide baseline information on ant diversity, behaviour, and resource use in the central Western Ghats. The study also emphasizes the importance of forest patches for conserving ant biodiversity in human-modified landscapes.