Carnivore communities in the Serengeti-Mara ecosystem are among the richest and most diverse in the world. However, human population growth and urban expansion have led to declines of carnivore species through both direct and indirect human-wildlife interactions. The Masaai Mara National Reserve (MMNR), contained within the Serengeti-Mara ecosystem, has been subjected to two different management systems which has led to high levels of anthropogenic disturbances in the Talek region and low levels in the Mara Triangle. We used the naturally occurring “experiment” in the MNNR, where the Mara Triangle can serve as a control for the highly disturbed Talek region, to tease apart changes in the composition and structure within the carnivore community in response to intense anthropogenic pressures. We developed a hierarchical community distance sampling model (CDSM) to estimate local carnivore abundances within each region using line transect data. By including all species from the community, even those that are rare or elusive, our model allows for a comprehensive assessment of species and community differences between regions. The CDSM accounts for species-specific differences in detection probabilities and estimates abundances for each species.
Results/Conclusions
There were 574 observations of 11 carnivore species with over 1800 individuals detected across both regions during 8400 km of survey transects. Less than 600 individuals were detected from 9 species during data collection in 13 replicate transects within the Talek region, while 1250 individuals from 11 species were detected within the Mara Triangle during 16 sampling replicates. We used the CDSM to estimate abundances of all 11 species of carnivores for both regions. The Talek region had high abundances of spotted hyena (Crocuta crocuta) and black-backed jackal (Canis mesomelas), but had moderate to low abundances of the other 9 carnivore species. The Mara Triangle had comparable abundances of spotted hyena and black-backed jackal to that of the Talek region, but also had high abundances of banded mongoose (Mungos mungo), bat-eared fox (Otocyon megalotis), and lion (Panthera leo). Our results suggest differences in carnivore community composition and structure between the highly disturbed Talek region and the pristine Mara Triangle. The differences in carnivore communities between regions suggests that the contrasting management styles may have led to differing anthropogenic pressures.