Explaining the birds and the bees: deriving habitat restoration targets from multi‐species occupancy models

Abstract

AbstractRiparian corridors can be highly biodiverse but are often degraded by human activities, and are therefore frequent targets of restoration actions. Yet managers often lack clear guidance on how to conserve or restore riparian vegetation structure and composition to promote wildlife biodiversity, due to the difficulty of balancing the needs of multiple species and taxonomic groups. We used independent multi‐species occupancy models to assess the response of riparian bird and bumble bee assemblages, respectively, to variation in vegetation structure and composition in montane riparian corridors. We sought to identify vegetation characteristics associated with relatively high richness across each taxonomic group to define target conditions for habitat restoration. Riparian bird occupancy increased with more willow (Salix spp.) cover and less overstory cover, while bumble bee occupancy increased with greater flowering plant richness, more forb cover, and less shrub cover. Relatively distinct habitat preferences of bumble bees and riparian birds emphasize the value of managing for habitat heterogeneity to promote biodiversity across multiple taxonomic groups. Multi‐species modeling distills the responses of numerous species down to a single estimate of a covariate effect for an assemblage of species and can provide land managers with empirically derived targets for habitat restoration that will benefit many species.