Monitoring Flower Visitation Networks and Interactions between Pairs of Bumble
Bees in a Large Outdoor Flight Cage
#MMPMID26982030
Lihoreau M
; Chittka L
; Raine NE
PLoS One
2016[]; 11
(3
): e0150844
PMID26982030
show ga
Pollinators, such as bees, often develop multi-location routes (traplines) to
exploit subsets of flower patches within larger plant populations. How
individuals establish such foraging areas in the presence of other foragers is
poorly explored. Here we investigated the foraging patterns of pairs of bumble
bees (Bombus terrestris) released sequentially into an 880m2 outdoor flight cage
containing 10 feeding stations (artificial flowers). Using motion-sensitive video
cameras mounted on flowers, we mapped the flower visitation networks of both
foragers, quantified their interactions and compared their foraging success over
an entire day. Overall, bees that were released first (residents) travelled 37%
faster and collected 77% more nectar, thereby reaching a net energy intake rate
64% higher than bees released second (newcomers). However, this prior-experience
advantage decreased as newcomers became familiar with the spatial configuration
of the flower array. When both bees visited the same flower simultaneously, the
most frequent outcome was for the resident to evict the newcomer. On the rare
occasions when newcomers evicted residents, the two bees increased their
frequency of return visits to that flower. These competitive interactions led to
a significant (if only partial) spatial overlap between the foraging patterns of
pairs of bees. While newcomers may initially use social cues (such as olfactory
footprints) to exploit flowers used by residents, either because such cues
indicate higher rewards and/or safety from predation, residents may attempt to
preserve their monopoly over familiar resources through exploitation and
interference. We discuss how these interactions may favour spatial partitioning,
thereby maximising the foraging efficiency of individuals and colonies.
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