Popis: |
The monetary value of livestock losses attributed to coyote (Canis latrans) predation in North America has increased during the past 20 years. In Texas, USA alone in 2011, these loses were estimated at $6.9 million. To mitigate coyote-related livestock losses, several lethal and nonlethal control methods have been developed. However, there remains a need for better information to guide management decisions regarding cost-effective predator control strategies for livestock production systems. We acquired data, which was used in the model, from published literature from 1960 to present day, subject matter experts, and anecdotal information on coyote ecology. We developed a systems dynamics simulation model to evaluate the economic impact of coyote control on an average-sized cattle (Bos spp.) operation (1,000 ha) for a conceptual 10-year period in Texas. We conducted a sensitivity analyses to validate the model and identify the most sensitive parameters. We tested 88 scenarios using common coyote management methods (i.e., aerial gunning, M-44 devices, snares, livestock guard animals (LGAs), calling and shooting, and foothold traps), combinations of multiple management methods, and number of applications per year (once per year, twice per year, continuous). Several management methods were cost effective at reducing calf predation when applied sparingly and under assumptions of skillful and dedicated application of coyote control methods. The most cost-effective method of coyote control to reduce calf depredation was the combined use of snares and LGAs. When applied 1 month prior to the primary calving month, the snare/LGA combination showed an 81% decrease in overall costs of calf loss and predator management during the 10-year period, respectively. Cost effectiveness of methods deteriorated as the number of applications per year increased. While these are useful results, the intangible values of coyotes through grazing benefits (i.e., fewer prey species such as lagomorphs on the landscape to compete for forage with cattle) and ecological benefits (i.e., mitigation of meso-predator release) were not included in the model. However, these benefits should be considered by ranchers before implementing lethal coyote management. |