Conservation implications of sex-specific landscape suitability for a large generalist carnivore

Aim Terrestrial mammal distribution models typically do not differentiate between sexes when making spatial predictions, which could have important conservation implications. As male carnivores are usually more risk tolerant and travel longer distances, male potential range should be larger and include more human-modified areas than female range. To evaluate if differences between females and males could influence their conservation planning, we quantified sex-specific suitable range for a recolonizing population of American black bears (Ursus americanus). Location We applied this method in Missouri, USA. Methods We collected telemetry data from 57 females and 43 male bears from 2010 to 2018. We used three machine-learning methods (generalized boosted regression, random forest and maximum entropy) to develop sex-specific distribution models, which were combined into a weighted average ensemble model and converted into a binary (presence/absence) model using an optimized threshold. We used 80% of individuals for each sex as training data, and 20% as evaluation data. Results All models had high predictive performance; the greatest uncertainty in model predictions corresponded with the periphery of the distributions, whereas there was high agreement in the core distribution. Male suitable range was 66% larger than female range, and males were predicted to occur in more human-modified areas and more likely to be present in developed land and agriculture. Main conclusions Distribution models based on data from both sexes, or that is male-biased, could overestimate the female (i.e., reproductive) range and potentially misrepresent the biologically relevant species distribution. This bias can potentially lead to misguided decisions and suboptimal use of resources. By improving models when sex-specific data are available, we can better focus resources in areas where there is reproductive potential, leading to more accurate assessments of species' conservation status and better identifying areas vital for species persistence.