Waggle Dance Distances as Integrative Indicators of Seasonal Foraging Challenges

Abstract

Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We “eavesdropped” on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable.

Determining the foraging potential of oilseed rape to honey bees using aerial surveys and simulations

“…From a variety of methods, it is known that honeybees will forage as far as c. 10-12 km from the hive (Beekman & Ratnieks, 2000;Ratnieks, 2007). But previous research that decoded honeybee waggle dances has shown that the actual foraging distances of honeybees in spring in the Brighton area are well below this maximum range with a median of 647 m, interquartile range of 364-1305 m, and with 95% of foraging within 2114 m (Couvillon, Schürch, & Ratnieks, 2014b;Garbuzov, Schürch, & Ratnieks, 2014). Other studies confirm that foraging distances in spring Figure 2.…”

“…Whiskers extend to the extreme value or 1.5 times the interquartile range, whichever is lower. The lower horizontal dashed line is the median spring honeybee foraging distance (647 m) and the upper horizontal dashed line is the 95%-quantile (2114 m) from published data on honeybees in the South East study area (Couvillon et al, 2014b). Additionally, the numbers given at the intersection of each box with these lines give the exact percentages of random points within the median and 95%-quantile spring foraging distance, respectively.…”

“…So far we have dealt only with the honeybee, for which good data on both foraging distances in our region and fields of OSR are available (Couvillon et al, 2014b;Garbuzov et al, 2015). Our findings are also applicable to other bees, as most bees are central place foragers.…”

Honeybees tune excitatory and inhibitory recruitment signalling to resource value and predation risk

“…Bees were trained to feeders 1 m or 100 m away from the focal colony. Honeybees usually forage and recruit for natural food at much greater distances (Couvillon, Schürch, & Ratnieks, 2014;Waddington, Herbert, Visscher, & Richter, 1994), but we chose these distances because 100 m was the furthest distance to which we could reliably train bees for all the tested sucrose concentrations.…”

“…Our results suggest that recruitment dancing decisions depend upon interactions between predation risk and cost of travel. However, honeybees typically forage over distances of more than 100 m (Couvillon et al, 2014) and future studies examining the effect of attacks at much greater distances would be beneficial.…”