Incorporating dynamic distributions into spatial prioritization

Aim: Species' distributions are generally treated as static for the purposes of prioritization, but many species such as migrants and nomads have distributions that shift over time. Decisions about priority actions for such species must account for this temporal variation, making planning for their conservation a complex problem. Here, we explore how dynamic distributions can be incorporated into a spatial prioritization, and suggest approaches for prioritizing conservation action when knowledge of species' movements is uncertain. Location: Australian rangelands, including the arid and semi-arid zones of central Australia and adjoining monsoonal tropics, although methods are applicable for any dynamic biodiversity feature. Methods: We used the decision-support software marxan to explore the impact of temporal dynamics on spatial conservation planning for a suite of 42 highly mobile birds across the study region. We explored scenarios comparing a static representation of species' distributions with four methods of integrating temporal dynamics: (1) accounting for temporal variability in distribution across months and years, (2) considering only monthly variability in distribution, (3) considering only annual variability in distribution and (4) considering only minimal distributions during spatial bottlenecks, ignoring distributions at other times. Results: Incorporating the temporal dynamics of species into spatial prioritization substantially changes the spatial pattern of conservation investment, increasing the overall area needed to be placed under conservation measures to achieve a specific target level of species protection. Targeting bottlenecks, locations critical to each species when its distribution is at a minimum, prioritizes a very different suite of sites to those chosen using the traditional approach of static distribution maps based on occurrences pooled across time. Main conclusions: Our results highlight the need to consider dynamic movements in the conservation planning process to ensure that mobile species are adequately protected. A static approach to conservation planning may misdirect resources and lead to inadequate conservation for mobile species.