The diversity of moths in a nature reserve in the Northern Cape, South Africa : Variation over time, depending on abiotic factors and differences between areas with different grazing types

Abstract: Land use changes globally have significant impacts on flora and fauna. In South Africa, extensive land is used for grazing by both domestic livestock and farmed native grazers. However, the effects of different grazing types on vegetation and fauna remain poorly understood. The Northern Cape, the country's largest province with a substantial agricultural sector, lacks comprehensive insect research. This study aimed to investigate moth diversity in an unstudied area, assessing species composition, dung beetle abundance, vegetational patterns, and the influence of abiotic factors and trap types on catches of moth in areas with varying grazing practices. Habitat types and habitat preferences were also examined. The research was conducted in the mid-north region of the Kalahari, Northern Cape province, between February and April 2023. Moths were captured using three different light sources, three times a week, and a subset of moths were counted and registered. The findings revealed the presence of at least 142 macromoth morphospecies, with higher abundance and species richness in areas grazed by domestic animals compared to native grazers. Dung beetle abundance was also greater in these areas. Notably, different habitats exhibited variations in moth occurrence, with specific morphospecies showing preferences for particular habitats. Plant species richness was higher in areas grazed by native grazers, while vegetational cover was greater in areas grazed by domestic animals. The study could show influence of moonlight, temperature, and windspeed on moth catches, and trap types affected the number of morphospecies captured. Surprisingly, the results contradict previous studies that suggested higher diversity in areas grazed by native grazers. Possible explanations include differences between the two areas in how beneficial the surrounding areas are, differences in abiotic factors, environmental productivity, habitat heterogeneity and plant species composition. Further studies of differences between areas with different grazing types in similar regions are needed to validate the findings of this study.