Multi-species hierarchical modeling reveals variable responses of African carnivores to management alternatives
Please contact the first author for questions about the code or data: Matthew T. Farr (matthewtfarr@gmail.com)
Carnivore communities face unprecedented threats from humans. Management regimes have variable effects on carnivores, where species may persist or decline in response to direct or indirect changes to the ecosystem. Using a hierarchical multi-species modeling approach, we examined the effects of alternative management regimes (i.e., active vs. passive enforcement of regulations) on carnivore abundances and group sizes at both species and community levels in the Masai Mara National Reserve, Kenya. Alternative management regimes have created a dichotomy in ecosystem conditions within the Reserve, where active enforcement of regulations maintains low levels of human disturbance in the Mara Triangle and passive enforcement of regulations in the Talek region permits multiple forms of human disturbance. The alternative management regimes have variable effects on 11 observed carnivore species. As predicted, some species, such as African lions and bat-eared foxes, had higher population densities in the Mara Triangle, where regulations are actively enforced. Yet, other species, including black-backed jackals and spotted hyenas, had higher population densities in the Talek region where enforcement is passive. Multiple underlying mechanisms, including behavioral plasticity and competitive release, are likely causing higher black-backed jackals and spotted hyena densities in the disturbed Talek region. All carnivore species that were observed in groups (i.e., greater than one individual), except spotted hyenas, had larger expected group sizes in the region with active enforcement. Our multi-species modeling framework reveals that carnivores do not react to management regimes uniformly, shaping carnivore communities by differentially producing winning and losing species. Some carnivore species require active enforcement of regulations for effective conservation, while others more readily adapt (and in some instances thrive) to passive enforcement and resulting anthropogenic disturbance. Yet, high levels of human disturbance appear to be negatively affecting the majority of carnivores, with potential consequences that may permeate throughout the rest of the ecosystem. Community approaches to monitoring carnivores should be adopted as single species monitoring may overlook important intra-community variability.
DataAnalysis: Contains code for modeling, analysis, and results
DataFormat: Contains code to format raw data for analysis and formatted data
PostAnalysis: Contains code to estimate posterior probabilities and to create figures
RawData: Contains CSV file of raw data
SupportingInformation: Contains code to run simulation and code to generate supporting information
PublishedPDF: PDF of published paper
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See the following subdirectories for code and metadata: DataAnalysis, DataFormat, PostAnalysis, SupportingInformation