Historical dietary ecology of black-backed jackals (Lupulella mesomelas) based on dental microwear texture analysis

Abstract

Within the diverse carnivore guilds of eastern and southern Africa, Black-backed Jackal (Lupulella mesomelas) populations are stable and thriving, unlike hundreds of mammal species in Africa that are adversely affected by human-mediated habitat loss and hunting. Population stability may be due to the extremely broad diet of the Black-backed Jackal or behavioral flexibility allowing dietary shifts to more prevalent resources. To assess geographic, seasonal, and historical dietary variation and change, we analyzed the diet in the Cape (L. m. mesomelas) and East African (L. m. schmidti) subspecies of Black-backed Jackal through dental microwear texture analysis from 1896 to 1970. We found no significant differences across geographically distinct subspecies or season. However, greater complexity was observed in the East African Black-backed Jackal after 1920—a period of population growth and industrialization in Sub-Sharan Africa. Our results imply that despite local differences in habitat, prey, and carnivorous contemporaries, dietary mechanical properties of Cape and East African black-backed jackals were relatively similar, representative of truly expansive and variable diets or similar utilization of different food items. Higher complexity over time implies a shift toward greater brittle food utilization, possibly in the form of bones and hard seeds, or greater contact with exogenous grit. We discuss these results in the context of mammal habitat loss and population decline, as well as increasing anthropogenic impact in Sub-Saharan Africa.