Simulated effects of roadkill and harvest on the viability of a recovering bobcat population

Abstract

Bobcats (Lynx rufus) were extirpated from many midwestern states in the mid‐1800s owing to habitat loss and overharvesting. Recently, bobcats have recolonized Ohio, USA, and neighboring states and given their furbearer status elsewhere, there is interest in opening a harvest season; however, demographic factors and viability of this population are currently unknown. We developed a spatial population simulation model to assess the long‐term viability of the bobcat population in Ohio in the face of 2 human‐induced factors limiting population growth: potential harvest and road mortality. We combined habitat suitability and road mortality risk data with vital rates for bobcats from Ohio and other populations to simulate possible scenarios for Ohio's population. Our baseline scenario simulations showed no risk of extinction for Ohio's bobcat population in the next 40 years, but population trajectories were lower and exhibited greater uncertainty when we modeled the population with a lower maximum density of animals per cell. At low harvest intensity (αh = 0.05), the bobcat population also exhibits low risk of extinction. When harvest intensity increases (αh = 0.1, 0.15) or when adults (≥2 yr) are targeted by harvest, simulations show declining populations, greater uncertainty in projections, and possible risk of extirpation. Our models indicated that if harvest and road mortality are additive, then the bobcat population could withstand marginal increases in road mortality (αr = 0.1) at low harvest intensity (αh = 0.05). Future increases in road mortality with higher harvest intensity (αh = 0.1, 0.15) were unsustainable. Our results can be used by wildlife managers to assist with decisions on population‐level management. This simulation model can easily be adapted for other large mammals and can be modified to assess a variety of ecological and anthropogenic influences to wildlife populations.

Managing Landscape Urbanization and Assessing Biodiversity of Wildlife Habitats: A Study of Bobcats in San Jose, California

“…By generating continuous density maps, this method clearly depicts the concentration trends of roadkill events in specific areas. The risk of road mortality for bobcats is significantly influenced by traffic levels [79], and roadkill incidents impact the activity and population of bobcats [80]. Increased traffic leads to an increased likelihood of vehicle encounters with wildlife [81].…”

Restoring eastern hellbender (Cryptobranchus a. alleganiensis) populations through translocation of headstarted individuals

“…In the absence of sufficient data to estimate spatiotemporal process variance in transition (survival) rates, we assumed that the parameter ranges represented parameter uncertainty, and were not a result of annual variation in environmental conditions (i.e., no environmental stochasticity). This approach is conservative in that it represents a worst-case scenario that maximizes the resulting estimated risk of extinction or decline (Dyck et al, 2023). These simulations were aimed at determining scenarios for rebuilding populations via headstart animals only, with no contributions from wild animals.…”