Selecting surrogate species for connectivity conservation

International audienceHabitat loss and fragmentation impede the movement of animals across landscapes causing biodiversity change. One strategy to counter these effects is to protect and restore habitat quality and connectivity for a diversity of species. How should surrogate species be selected to represent a diversity of needs from a larger species pool? Using a recent method to prioritize multispecies habitat networks, we tested how the selection of surrogate species affects prioritization outcomes. We ran prioritization schemes using subsets of N (N = 0, 1, 3, 5, 7, 9) species selected from a 14-species reference set. Selection was based on different concepts of surrogate species: umbrella, taxonomy, habitat diversity, movement diversity, movement and habitat diversity. Prioritization outputs were compared to the 14-species set for their effectiveness and comprehensiveness at retaining habitat quality and connectivity criteria, and for their spatial congruence. We show that species-based surrogates perform better than habitat-based surrogates and that a moderate number of species (5-7) might be sufficient to capture the needs of a broader species pool for one habitat type (forest). However, how species are selected matters as much as how many. The best performing approach is to select species representing a diversity of habitat and/or movement needs. Umbrella or taxonomy-based selections were less effective and comprehensive. Our results can guide the selection of surrogate species when designing a prioritization plan for regional connectivity conservation. We recommend favoring systematic trait-based species selection over single-species, umbrella or taxonomy-based selections. When a proper species-based surrogate approach cannot be done, a habitat-based surrogate approach might still be a useful alternative