Diet composition, body condition and sexual size dimorphism of the common African toad (Amietophrynus regularis) in urban and agricultural landscape

Abstract Land use and land cover change (LULCC) are major drivers of global biodiversity loss. The conversion of natural habitats into human-modified landscapes poses novel and multifaceted environmental stressors to organisms, influencing their ecology, physiology, life history and fitness. Although the effects of LULCC have been studied extensively at the community level, there is scant information about its effect on population and individual characteristics. We assessed the diet composition, body condition, and sexual size dimorphism of the common African toad (Amietophrynus regularis) in urban and agricultural landscape. Diet composition was evaluated using gut content analysis, while body condition was measured using residual mass index. Overall, 935 prey items comprising six classes, at least 18 orders and 31 families were obtained from toads. This broad dietary niche suggested that Amietophrynus regularis is a generalist predator. The family Formicidae was the most consumed prey item, with a frequency of occurrence above 80% at both sites. We found no sex- or habitat-biased dietary partitioning in the toads. A statistically significant positive correlation existed between snout-vent-length (SVL) and diversity of prey items (Pearson’s correlation r = 0.999, p ≤ 0.0001) for toads from farmland, which also had better body conditions. The toads showed female-biased sexual size dimorphism, but males had longer tibio-fibula, radio-ulna, foot, and distal fore limbs. This study is probably the first to assess the diet composition, body condition and sexual size dimorphism of Amietophrynus regularis simultaneously. The ecological, evolutionary and conservation implications of our findings are discussed.