Albuquerque, João Miguel Porfírio de2026-02-102026-02-102025http://hdl.handle.net/10400.5/116967Tese de mestrado, Biologia da Conservação, 2025, Universidade de Lisboa, Faculdade de CiênciasUnderstanding species' dietary ecology is essential to unravelling the mechanisms that enable coexistence and clarifying ecological roles and evolutionary adaptations. Swifts (Apodiformes: Apodidae) and swallows (Passeriformes: Hirundinidae) are highly adapted birds to an aerial insectivorous lifestyle. However, dietary data remain scarce, especially for Afrotropical species. With many of these species breeding and foraging in sympatry, the question arises of how resource partitioning occurs, avoiding competitive exclusion. In this study, we employed DNA metabarcoding and next-generation sequencing to characterise the diets of four understudied and co-occurring West African aerial insectivores: the red-chested swallow (Hirundo lucida), wire-tailed swallow (Hirundo smithii), white-rumped swift (Apus caffer), and little swift (Apus affinis). This study represents the first application of these molecular techniques to dietary analysis for Africa's most highly aerial insectivore bird species. Faecal samples were collected in Guinea-Bissau using mist nets and collection platforms in habitats ranging from smallholder rice fields to urban areas. We aimed to (1) characterise the dietary composition and diversity of the four species, (2) quantify dietary overlap and niche partitioning, and (3) assess temporal shifts in swallow diets. Our results revealed broad prey diversity and substantial dietary overlap across species, consistent with generalist feeding behaviours and opportunistic prey capture. The pronounced overlap in diet suggests shared exploitation of aerial prey resources and points to convergence in feeding strategies among these aerial insectivores. Still, subtle but consistent dietary differences were detected among species, indicating niche partitioning likely influenced by morphology, habitat use and insect abundance. These small-scale differences may reduce direct competition and facilitate coexistence within shared environments. Combining high overlap and moderate dietary segregation highlights how generalist predators with similar ecological roles can coexist by balancing shared resource use and species-specific environmental filters. Conservation efforts should prioritise protecting diverse foraging habitats to support these species amid ongoing environmental change.application/pdfengApodidaeHirundinidaeDietary metabarcodingGuinea-BissauSympatric speciesmaster thesis204121884