Understanding wildlife responses to human disturbance through simulation modelling: A management tool

Abstract

With conservation awareness and the demand for wildlife preservation increasing, ecotourism and outdoor recreational activities are becoming more popular. If such activities go unmanaged, the disruption to many species may have implications on their breeding success, survival and abundance and these, in turn, may have cascading ecosystem effects. By developing management strategies, through the application of simulation models, to simultaneously maintain recreational opportunities and sustain wildlife populations, these detrimental impacts can be minimised. Simulation of Disturbance Activities (SODA) is a spatially explicit individual-based model designed as a flexible and transferable practical tool to explore the effects of spatial and temporal patterns of anthropogenic disturbance on wildlife. Two case studies were used to illustrate the capabilities of SODA, one explored the effect of potential park designs on a nesting population of yellow-headed blackbirds ( Xanthocephalus xanthocephalus) in Calumet, IL and the other investigated the influence of visitor frequency on the breeding success of barbastelle bats ( Barbastella barbastellus) in the south west of England. For the yellow-headed blackbird, SODA revealed that pathways in close proximity to their main nesting and foraging habitat increased the level of disturbance experienced by the birds, although not to an extent that was detrimental to their breeding success. However, establishing paths beyond the zone of influence may ensure that the yellow-headed blackbird and other avian species continue to use the area in its entirety. In the second case study, SODA demonstrated that female barbastelle bats are significantly disturbed by the unrestricted movement of recreationists at their breeding colony site. However, SODA also revealed a lack of confidence in the critical energetic threshold value applied in the simulation. Subsequently, the overall effect of anthropogenic disturbance on the breeding success of this species could not be fully ascertained.