Galiano Island harnesses iNaturalist to detect historical changes in the local bumble bee community

Andrew D. F. Simon, Lincoln R. Best, Brian M. Starzomski

Three bumble bee species have disappeared from Galiano Island, where they have not been seen since 1990: the Western Bumble Bee (Bombus occidentalis), the Indiscriminate Cuckoo Bumble Bee (Bombus insularis), and Suckley’s Cuckoo Bumble Bee (Bombus suckleyi).

The Yellow-faced Bumble Bee (Bombus vosnesenskii) is a new arrival on Galiano Island, having largely replaced the Western Bumble Bee in parts of its former range.

We recently conducted a systematic survey targeting bumble bees, and combined with data from the community science platform iNaturalist, we’ve found strong evidence documenting historical change in this island community. Our results are reported in the paper “Evidence of bumble bee extirpation and colonization: Galiano Island, British Columbia, Canada”, recently accepted in the journal Northwest Science, which will be published soon. Below, we present the accepted paper for anyone who might want to see it now.

Baseline data are rare for many insect groups, making population analysis difficult. As a result, important pollinator species may undergo dramatic declines unnoticed. The emergence of community science platforms such as iNaturalist holds promise to address this challenge, as a novel approach to tracking biodiversity change. In this paper, we present evidence for historical change in an island bumble bee community, documenting the probable extirpation of three bumble bee species and a recent colonization event. Data from both intensive sampling using blue vane traps and from iNaturalist observations converged on the same estimate of species richness in the present data community, which significantly differed from our estimate of richness in the historical community. These results demonstrate the potential for community science to aid in the detection of biodiversity change through a comparison of historical collections and crowd-sourced biodiversity data. Looking forward, where collections data are lacking, data from iNaturalist may provide the baselines we need to understand future change.

In Press in Northwest Science; Accepted September 16, 2022. Pre-print available on