COS 140-2 - The impacts of the road network on maned wolf Chrysocyon brachyurus persistence in Brazil

Thursday, August 10, 2017: 8:20 AM
B113, Oregon Convention Center
Priscilla Barbosa1, Nathan H. Schumaker2, Alex Bager1 and Clara Grilo1, (1)Biology Department, Centro Brasileiro de Estudos em Ecologia de Estradas, Lavras, Brazil, (2)Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR

The expansion of Brazil’s road network in the last decade presents an emergent threat to biodiversity. One of the major concerns for wildlife is the additional mortality due to collisions with vehicles. The maned wolf (Chrysocyon brachyurus) is a South American canid classified as Near Threatened by the IUCN, with an occurrence mainly in the Brazilian savannah. Currently they experience road-kill rates that range from 0.011 to 0.083 ind./km/year. This species can be particularly vulnerable to road mortality since they occur in low population densities and have low reproductive rates, which limit the population recovery when facing additional mortality. However, knowledge of the effects on maned wolves of this observed additional mortality due to traffic is still scarce. The main goal of this study is to evaluate the impact of the road network on maned wolf population persistence in Brazil using different scenarios of road-kill rates. We developed a spatially-explicit, individual-based forecasting model to evaluate the consequences that road mortality can impose on maned wolf populations dynamic, size, and distribution. We ran 44 scenarios by varying the effects of roads on individuals movements, including avoidance, permeability, and mortality.


Our preliminary findings show that even low rates of road-kill result in severe population declines. Population size can be reduced by between 10 and 23%. Scenarios that include only avoidance and successful crossing did not change the species’ final population size. With this study, we intend to provide guidance to managers and conservation biologists
in order to prioritize mitigation efforts such as the fencing of roads or the placement of wildlife overpasses. Furthermore, this approach will contribute to improving PVAs method when working with large home range species with low available data.