Not all who wander are lost: nest fidelity in Xylocopa virginica examined by mark recapture

Abstract

Relocation to novel nests (sometimes called drifting) in flying Hymenoptera is often interpreted as the result of navigation error and guard bees erroneously admitting foreign individuals into the nest. We studied nest fidelity and nest relocation of both females and males in a nesting aggregation of Xylocopa virginica in southern Ontario, Canada, where females can nest either solitarily or socially. Adult female and male bees were trapped at nest entrances, individually paint marked, and then released. Subsequent recapture patterns were used to assess nest fidelity: that is, how faithful individuals were to their home nest and how often they moved to another nest. Bees were considered to have relocated if they were recaptured in a nest different from the one in which they were initially trapped, indicating that they had spent at least one night in a new nest. Some females were only captured in one nest, some occasionally moved to new nests, temporarily or permanently, and a few were never caught in the same nest twice. In addition, females relocated to nests that were further away in 2007 when population density was low, suggesting that they seek out and claim nesting spaces when they are available. Males relocated more frequently than females, with most drifting from nest to nest in no obvious pattern. This indicates that males spend the night wherever space is available or in nests nearest to their territories. This study reveals that for both female and male X. virginica, nest membership is not as stable as once thought.

Low relatedness and frequent inter-nest movements in a eusocial sweat bee

“…Such full-sib groups distributed in multiple nests attest that either the mother or the offspring have moved between nests (e.g. Packer 1986;Ulrich et al 2009;Peso and Richards 2011).…”

Ergonomic skew and reproductive queuing based on social and seasonal variation in foraging activity of eastern carpenter bees (Xylocopa virginica)

“…In Georgia, estimates of daily activity were considerable lower (a maximum of six trips per day in Georgia; Gerling and Hermann 1978), perhaps reflecting greater access of bees to pollen resources in that population. Peso and Richards (2011) proposed that transient females move to new nests seeking improved reproductive opportunities. This hypothesis was supported by our observations that about onethird (19/51) of all foragers moved from their natal nests to new nests (Table 2).…”

“…To catch bees, plastic cup traps were placed over nest entrances early each morning prior to flight activity (Peso and Richards 2011). Once a bee was caught, the trap containing the captured bee was chilled in a cooler for 10 min, while a replacement trap was placed over the nest entrance.…”

“…Observations of marked females also demonstrate that many females relocate from their natal nests to new nests throughout the course of the breeding season (Peso and Richards 2011). The transient bees are thought to be seeking improved reproductive opportunities in new nests where they might be more likely to become dominant foragers and reproductives (Peso and Richards 2011). All these lines of circumstantial evidence suggest dynamic social relationships among co-nesting females, including competition among co-nesting females for reproductive opportunities.…”

“…By the end of a breeding season, social nests usually contain one highly worn female, corresponding to the dominant forager observed in southern populations, but also one to three additional females with enough wing damage to suggest that they also spent considerable time in flight and foraging activities (Richards 2011). Observations of marked females also demonstrate that many females relocate from their natal nests to new nests throughout the course of the breeding season (Peso and Richards 2011). The transient bees are thought to be seeking improved reproductive opportunities in new nests where they might be more likely to become dominant foragers and reproductives (Peso and Richards 2011).…”