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

Abstract

Riparian 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.

Western bumble bee: declines in the continental United States and range‐wide information gaps

“…Please see www.usgs.gov/westernbb for details. More research focusing on the uncertainties around the stressors likely to have the largest effects (pathogens, pesticides, climate, and habitat loss), evaluating the success of various conservation efforts (e.g., Cole et al 2019), and assessing the locations and appropriate taxa level of the two subspecies is urgently needed. In addition, community science data collection efforts such as Bumble bee watch and iNaturalist can be used in model validation and for learning locations of remnant populations.…”

Climate change winners and losers among North American bumblebees

“…Occupancy models estimate a species' probability of occurrence across a set of sites and have been used to model associations between bumblebee presence and various landscape and climate characteristics [1,24,25]. Such presence/ absence data are not as information-rich as abundance data, and it is possible for the two metrics to exhibit conflicting patterns.…”

Positive impact of postfire environment on bumble bees not explained by habitat variables in a remote forested ecosystem

“…However, canopy openness and floral species richness did influence detection probability. These results suggest that there may be a gap In general, past work has shown that bumble bees tend to be more abundant in areas with greater floral species richness and abundance and lower shrub or canopy cover (Cole et al, 2019;Grundel et al, 2010;Loffland et al, 2017;Steinert et al, 2021).…”

“…As these models are relatively new, they have not been used in many previous bumblebee ecology studies, perhaps also because they require repeat visits to survey sites which necessarily means sampling fewer different sites (under a fixed amount of survey effort). However, even when employed, previous work has not accounted for the potential influence of habitat variables on detection probability, either not including any parameters on detection (Evans et al, 2019) or only including time of year, time of day, or survey effort as predictors of detection (Cole et al, 2019; Loffland et al, 2017).…”