Evolutionary Ecology and Conservation Implications of Diet Specialization in Nigerian Forest Primates

Diet specialization represents a key evolutionary trait governing the vulnerability of primate species to habitat modification and the depletion of food plant resources. While diet breadth data exist for several African primate species from other range countries, the diet composition, food plant preferences, and diet specialization indices of primate communities in Nigerian forest reserves have not been systematically studied. This dissertation investigates the evolutionary ecology of diet specialization and its conservation implications for four sympatric primate species in Nigerian forest reserves spanning Cross River State (South South) and Oyo State (South West). Long-term behavioral observation data were collected over 18 months for red-capped mangabeys, mona monkeys, olive baboons, and Western patas monkeys. Phenology monitoring of 500 food plant individuals tracked fruit, seed, and leaf availability throughout the study period. DNA metabarcoding of fecal samples provided dietary composition data unbiased by observer limitations. Phylogenetically controlled comparative analyses examine the evolutionary determinants of diet specialization within the study community. Results demonstrate that mangabeys exhibit the narrowest diet breadth and the strongest positive selectivity for fig species, predicting their high vulnerability to habitat loss that reduces fig density. An original dietary vulnerability index is proposed for integration into conservation status assessments of African primates. The dissertation advances primate evolutionary ecology and provides actionable dietary vulnerability metrics for conservation managers. Keywords: primate diet, diet specialization, evolutionary ecology, Nigerian forests, conservation vulnerability