A landscape‐scale study of bumble bee foraging range and constancy, using harmonic radar

Abstract

Summary1. Bumble bees play a vital role in the pollination of many crops and wild¯owers, and plans for their conservation require a knowledge of the dynamics and spatial scale of their foraging¯ights, which are, at present, poorly understood. 2. We investigated the foraging range and constancy of two colonies of bumble bees Bombus terrestris L. on a mixed arable farm using harmonic radar, which has a unique capability to record the trajectories of insects¯ying at low altitude in the ®eld. 3. Foraging bees were ®tted with lightweight radar transponders and tracked as they¯ew to and from the nest to forage. The resulting tracks gave information on length, direction and straightness of foraging routes. Superimposition onto a map of the foraging landscape allowed interpretation of the bees' destinations in relation to the spatial distribution of forage. 4. Outward tracks had a mean length of 275´3 P 18´5 m (n = 65) and a range of 70±631 m, and were often to forage destinations beyond the nearest available forage. Most bees were constant to compass bearing and destination over successive trips, although one bee was tracked apparently switching between forage patches. Both outward and return tracks had a mean straightness ratio of 0´93 P 0´01 (n = 99). The bees' ground speeds ranged from 3´0 m s ±1 to 15´7 m s ±1 (n = 100) in a variety of wind conditions. 5. The results support the hypothesis that bumble bees do not necessarily forage close to their nest, and illustrate that studies on a landscape scale are required if we are to evaluate bee foraging ranges fully with respect to resource availability. Such evaluations are required to underpin assessments of gene¯ow in bee-pollinated crops and wild¯owers. They are also required when making decisions about the management of bees as pollinators and the conservation of bee and plant biodiversity.

The single Andigenum origin of Neo-Tuberosum potato materials is not supported by microsatellite and plastid marker analyses

“…Potatoes require vibratile buzzing to release pollen, and bumblebees are their main pollinators (Johns and Keen 1986;Scurrah et al 2008). Bumblebees typically forage over 70-631 m (Osborne et al 1999), but pollen from one Xower is usually deposited only across a limited number that are subsequently visited and gene Xow is generally restricted to very near neighbors (McPartlan and Dale 1994;Scurrah et al 2008). Only about 20% of seeds were cross-pollinated in the original Neo-Tuberosum experiment (Glendinning 1976).…”

Activity rhythm and action range of workers of the invasive hornet predator of honeybees Vespa velutina, measured by radio frequency identification tags

“…It implies that individuals optimally explore a foraging area and are able to return to their nest after foraging for resources, to store, and to share it with the members of the group family (Bell, 1990; Houston & McNamara, 1985; Orians & Pearson, 1979). Nesting site choice results from the trade‐off among the habitability of the location, its safety from predators and the distance to resources (Osborne et al., 1999, 2008; Pyke, Pulliam, & Charnov, 1977; Williams & Kremen, 2007). To limit foraging costs, individuals optimize different parameters linked to foraging such as the distance they travel (Bell, 1990; Pyke, 1984).…”

“…For example, Bombus terrestris workers basically forage in a 1,000‐m range, but may travel up to 4,300 m from their colony to collect valuable resources (Goulson & Osborne, 2009; Goulson & Stout, 2001; Osborne et al., 1999; Wolf & Moritz, 2008). They are, however, able to find their way home up to ca.…”

Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide–tolerant crops

“…Spatial-distribution patterns and foraging strategies also influence the functional form of the relation between scarce prey and highly mobile predators, especially where dispersal behaviour is altered by hunger (Holling 1966). Likewise the functional relation between floral resources and highly mobile pollinating species is complicated by the spatial distribution of resources over the pollinator's foraging range (which may cover many hectares) together with their preferences and navigational ability (Osborne et al 1999;Cresswell et al 2000). The degree of resource limitation also depends on the level of apparency of the resource to the consumer and any direct influence of primary producers on the third trophic level (e.g.…”