Taking a semi-local dynamic snapshot as a possibility for local homing in initially naïve bumblebees

Abstract

AbstractFor central place foragers, such as bumblebees, it is essential to return reliably to their nest. Instead of just flying away to forage, bumblebees, leaving their inconspicuous nest hole for the first time, need to gather and learn sufficient information about the surroundings to allow them to return to the nest at the end of their trip. Therefore, we assume an intrinsic learning program that manifests itself in the flight structure immediately after leaving the nest for the first time.In this study, we recorded and analysed the first outbound flight of individually marked naïve bumblebees in an indoor environment. We found characteristic loop-like features in the flight pattern that appear to be necessary for the bees to acquire environmental information and might be relevant for finding the nest hole after a foraging trip.Despite common features in their spatio-temporal organisation, the first departure flights from the nest are characterised by a high level of variability in their loop-like flight structure across animals. Changes in turn direction of body orientation, for example, are distributed evenly across the entire area used for the flights without any systematic relation to the nest location. By considering the common flight motifs as well as this variability, we came to the hypothesis, that a kind of dynamic snapshot is taken during the early phase of departure flights in the close vicinity of the nest location. The quality of this snapshot is hypothesised to be ‘ tested’ during the later phases of the departure flights concerning its usefulness for local homing.