A review of methods for the study of bumble bee movement

Abstract

Understanding animal movement is critical for conservation planning, habitat management, and ecological study. However, our understanding is often limited by methodological constraints. These limitations can be especially problematic in the study of ecologically and economically important pollinators like bumble bees, where several aspects of their biology limit the feasibility of landscape-scale studies. We review the methods available for the study of bumble bee movement ecology, discussing common limitations and tradeoffs among several frequent data sources. We provide recommendations on appropriate use for different life stages and castes, emphasizing where recent methodological advances can help reveal key components of understudied parts of the bumble bee life cycle such as queen movement and dispersal. We emphasize that there is no one correct method and encourage researchers planning studies to carefully consider the data requirements to best address questions of interest. foraging / dispersal / mark-recapture / radio-tracking / sibship assignment Electronic supplementary material The online version of this article (

Forests do not limit bumble bee foraging movements in a montane meadow complex

“…Although the distances observed for B. bifarius were shorter, these appear to be species‐specific differences and not a response of bumble bee foraging at high elevations. The explanation offered in prior studies, that foraging range is reduced as floral resource density increases, may be true, but we contend that the observed short foraging ranges in prior studies are likely artefacts of study design rather than bumble bee foraging patterns in high‐elevation environments (reviewed in Mola & Williams, ). It seems likely that, as resource density increases, foraging range is reduced (Pope & Jha, ), which could occur in high‐elevation environments with dense, co‐flowering sub‐alpine plant communities, but we do not think this occurs as a de facto consequence of foraging within high‐elevation environments.…”

“…Species‐specific movement differences among bumble bees are fairly well documented for European species (Knight et al ., ; Redhead et al ., ), but patterns are only beginning to emerge for North American species. Although it seems as if the absolute estimate of foraging distance is highly sensitive to a study's methodology or landscape, clear and consistent relative patterns of foraging distance emerge across studies (Mola & Williams, ). Our results support prior studies suggesting that B. bifarius has a relatively short foraging range (Geib et al ., ), whereas B. vosnesenskii is capable of much longer‐distance flight (Rao & Strange, ; Jha & Kremen, ; Mola, ).…”

“…We estimated colony‐specific foraging distances by calculating the mean of linear distances between each colony member and their shared centroid. Although this estimate is likely an underestimate of a colony's true foraging range, it represents a reliable estimator for relative comparisons between species within a common landscape (Pope & Jha, ; Mola & Williams, ). We tested for statistically significant differences in colony‐specific foraging distances between species using a Wilcoxon Rank‐Sum test to account for non‐normally distributed estimates.…”

“…Recent worldwide declines in their populations (Grixti et al ., ; Williams & Osborne, ) have sparked intense interest in understanding the role habitat structure, floral resource distribution, and species‐specific differences in movement capacity may play in their persistence (Westphal et al ., ; Redhead et al ., ). However, the difficulty of studying small, fast‐flying organisms with cryptic nesting habits has limited our understanding of large‐scale bumble bee movement, especially with regard to landscape context (Mola & Williams, ).…”

“…Others suggest that foraging range may be reduced in high‐elevation environments due to the dense and short‐lived blooming period typical of these habitats (Elliott, ; Geib et al ., ). However, these findings may be artefacts of low sample abundance and the tendency of bumble bee workers to exhibit high site fidelity (Manning, ; Comba, ; Ogilvie & Thomson, ), both of which can reduce the estimated range of bumble bee foraging and overestimate the influence of putative barriers (Mola & Williams, ). Furthermore, even if individuals exhibit strong site fidelity or are limited by barriers, there may be strong motivation for siblings to forage widely separated from each other to gain access to complementary food resources for the colony (Mandelik et al ., ).…”