Informing apex predator management: population viability analysis of dingoes under different management scenarios

Abstract

Context: Along with other large carnivores, dingoes (variously Canis dingo, C. lupus dingo, and C. familiaris) can come into conflict with humans, especially when they are habituated to people and associate them with food. Management actions can range from no response, through removal of target individuals, to indiscriminate culls. Aims: To model a known dingo population where lethal management occurs and to predict how different approaches to lethal management might impact the population over the next 20 years. Methods: We used a software package to model a baseline scenario with no lethal management, and then several current, past or plausible lethal management scenarios for the population, including removing different age-sex classes at various levels and frequencies. Key results: Modelled lethal management decreased the probability of population survival in all scenarios tested, particularly when individuals above the age of 2 years were targeted, and when lethal control was modelled to increase in frequency. Models indicated that targeted lethal management of subadult (age 1–2) males resulted in the highest probability of population persistence, which contrasted most markedly with pack removal through indiscriminate culls. Conclusions: Modelling identified that targeting problem individuals for lethal control was more sustainable for the population than indiscriminate culls. Research indicates that ‘problem’ animals are often subadult males. Modelling the removal of subadult (age 1–2) males affects the population less than removal of other age-sex classes. This implies that targeted lethal management poses less risk to population persistence than indiscriminate culls, since culling is more likely to remove older animals and females. Modelled increases in the number of animals controlled and the frequency of that control decreases the population’s likelihood of persistence. Implications: Lethal management strategies may have serious impacts on the persistence of carnivore populations, particularly when strategies involve broadscale indiscriminate culls. Adoption of best-practice targeted individual management requires investment in monitoring and identification. While the uptake of individual-focused management is not feasible in many scenarios, more widespread uptake would improve wildlife management outcomes.