title: Using empirical models of species colonization under multiple threatening processes to identify complementary threat-mitigation strategies.
abstract: Approaches to prioritize conservation actions are gaining popularity. However, limited empirical evidence exists on which species might benefit most from threat mitigation and on what combination of threats, if mitigated simultaneously, would result in the best outcomes for biodiversity. We devised a way to prioritize threat mitigation at a regional scale with empirical evidence based on predicted changes to population dynamics-information that is lacking in most threat-management prioritization frameworks that rely on expert elicitation. We used dynamic occupancy models to investigate the effects of multiple threats (tree cover, grazing, and presence of an hyperaggressive competitor, the Noisy Miner (Manorina melanocephala) on bird-population dynamics in an endangered woodland community in southeastern Australia. The 3 threatening processes had different effects on different species. We used predicted patch-colonization probabilities to estimate the benefit to each species of removing one or more threats. We then determined the complementary set of threat-mitigation strategies that maximized colonization of all species while ensuring that redundant actions with little benefit were avoided. The single action that resulted in the highest colonization was increasing tree cover, which increased patch colonization by 5% and 11% on average across all species and for declining species, respectively. Combining Noisy Miner control with increasing tree cover increased species colonization by 10% and 19% on average for all species and for declining species respectively, and was a higher priority than changing grazing regimes. Guidance for prioritizing threat mitigation is critical in the face of cumulative threatening processes. By incorporating population dynamics in prioritization of threat management, our approach helps ensure funding is not wasted on ineffective management programs that target the wrong threats or species.
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
authors.forename: Ayesha I T
authors.initials: AI
authors.lastname: Tulloch
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.|Department of Wildlife, Fisheries, and Conservation Biology, University of Maine, Orono, ME, 04469, USA.
authors.forename: Alessio
authors.initials: A
authors.lastname: Mortelliti
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Kay
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Florance
authors.affiliation: Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Lindenmayer
mesh_terms: D000818:Animals; D001315:Australia; D044822:Biodiversity; D001717:Birds; D003247:Conservation of Natural Resources; D065928:Forests
keywords: amenazas acumulativas; aves; birds; conservation action prioritization; cumulative threats; dinámicas ecológicas; dynamic patch occupancy model; ecological dynamics; grazing regimes; habitat loss; manejo de amenazas prioritarias; modelo de ocupación de fragmento dinámico; priority threat management; priorización de acciones de conservación; pérdida de hábitat; regímenes de pastoreo