2021 Minnesota bumble bee survey data

Mounting evidence of bumble bee declines has stimulated an interest in monitoring and conservation. Understanding the influence of land use on occupancy patterns of imperiled species is crucial to successful recovery planning. Using detection data from community surveys, we assessed land use associations for seven bumble bee species in Minnesota, U.S.A., including an endangered species (Bombus affinis Cresson). We used multi-species occupancy models to assess the effect of three major land use types (developed, agricultural, and natural) within 0.5 and 1.5 km on occupancy of seven Bombus species, while accounting for detection uncertainty. Bombus affinis was positively associated with developed landscapes at both scales, suggesting that urban areas can provide conservation benefits for this species in the Midwest. Further, we show that B. affinis occupancy and detection are highest in developed landscapes and lowest in agricultural landscapes, representing an inverse relationship with the relative land use ratios of these landscapes in Minnesota. Occupancy of two bumble bee species had strong positive associations with natural landscapes within 1.5 km and two species had strong negative associations with agricultural landscapes within 1.5 km. Our results suggest that best practices for imperiled Bombus monitoring and recovery planning depends upon the surrounding major land use patterns. We provide recommendations for urban planning to support B. affinis based on conservation success in the metropolitan areas of Minneapolis-St. Paul. We also encourage substantial survey effort be employed in agricultural and natural regions of the state historically occupied by B. affinis to determine the current occupancy state.