Training for Defense? From Stochastic Traits to Synchrony in Giant Honey Bees (Apis dorsata)

Waddoup

Hötzl

et al. 2014

Insects

Self Cite

We investigated intraspecific aggression in experimental nests (expN1, expN2) of the giant honey bee Apis dorsata in Chitwan (Nepal), focusing on interactions between surface bees and two other groups of bees approaching the nest: (1) homing “nestmate” foragers landing on the bee curtain remained unmolested by guards; and (2) supposed “non-nestmate” bees, which were identified by their erratic flight patterns in front of the nest, such as hovering or sideways scanning and splaying their legs from their body, and were promptly attacked by the surface bees after landing. These supposed non-nestmate bees only occurred immediately before and after migration swarms, which had arrived in close vicinity (and were most likely scouting for a nesting site). In total, 231 of the “nestmate” foragers (fb) and 102 approaches of such purported “non-nestmate” scouts (sc) were analysed (total observation time expN1: 5.43 min) regarding the evocation of shimmering waves (sh). During their landing the “nestmate” foragers provoked less shimmering waves (relnsh[fb] = 23/231 = 0.0996, relnsh[sc] = 75/102 = 0.7353; p <0.001, χ2-test) with shorter duration (Dsh[fb] = 197 ± 17 ms, Dsh[sc] = 488 ± 16 ms; p <0.001; t-test) than “non-nestmates”. Moreover, after having landed on the nest surface, the “non-nestmates” were attacked by the surface bees (expN1, expN2: observation time >18 min) quite similarly to the defensive response against predatory wasps. Hence, the surface members of settled colonies respond differently to individual giant honey bees approaching the nest, depending on whether erratic flight patterns are displayed or not.

Section: Discussionmentioning

confidence: 99%

Intraspecific Aggression in Giant Honey Bees (Apis dorsata)

Waddoup

Hötzl

et al. 2014

Insects

Self Cite

“…They nest in the open (Seeley et al 1982) and are, therefore, especially exposed to predators, such as mammals (Kastberger 1999), birds (Seeley et al 1982; Kastberger and Sharma 2000) and wasps (Seeley et al 1982; Kastberger et al 2008, 2010). Their most prominent defensive behaviour against such threats is shimmering, which generates repetitive social waves with anti-predatory impact (Kastberger et al 2008, 2010, 2012, 2013; Weihmann et al 2012). In shimmering, bees at the nest surface, predominantly younger cohorts (Lerchbacher et al, submitted) in the quiescent regions peripheral to the mouth zone (Kastberger et al 2011b), show simultaneous and cascaded actions (Schmelzer and Kastberger 2009) whereby their abdomens are flipped upwards at an angle between 20° and 120° (Kastberger et al 2011a, b).…”

Section: Introductionmentioning

confidence: 99%

Social waves in giant honeybees (Apis dorsata) elicit nest vibrations

Kastberger

Hoetzl

2013

Naturwissenschaften

Self Cite

Giant honeybees (Apis dorsata) nest in the open and have developed a wide array of strategies for colony defence, including the Mexican wave-like shimmering behaviour. In this collective response, the colony members perform upward flipping of their abdomens in coordinated cascades across the nest surface. The time–space properties of these emergent waves are response patterns which have become of adaptive significance for repelling enemies in the visual domain. We report for the first time that the mechanical impulse patterns provoked by these social waves and measured by laser Doppler vibrometry generate vibrations at the central comb of the nest at the basic (=‘natural’) frequency of 2.156 ± 0.042 Hz which is more than double the average repetition rate of the driving shimmering waves. Analysis of the Fourier spectra of the comb vibrations under quiescence and arousal conditions provoked by mass flight activity and shimmering waves gives rise to the proposal of two possible models for the compound physical system of the bee nest: According to the elastic oscillatory plate model, the comb vibrations deliver supra-threshold cues preferentially to those colony members positioned close to the comb. The mechanical pendulum model predicts that the comb vibrations are sensed by the members of the bee curtain in general, enabling mechanoreceptive signalling across the nest, also through the comb itself. The findings show that weak and stochastic forces, such as general quiescence or diffuse mass flight activity, cause a harmonic frequency spectrum of the comb, driving the comb as an elastic plate. However, shimmering waves provide sufficiently strong forces to move the nest as a mechanical pendulum. This vibratory behaviour may support the colony-intrinsic information hypothesis herein that the mechanical vibrations of the comb provoked by shimmering do have the potential to facilitate immediate communication of the momentary defensive state of the honeybee nest to the majority of its members.Electronic supplementary materialThe online version of this article (doi:10.1007/s00114-013-1056-z) contains supplementary material, which is available to authorized users.

“…The experiments were conducted with Apis dorsata nests in the village of Sauraha, at the border of the Chitwan National Park, Nepal. Preliminary experiments had been carried out in 2003 (Kastberger et al 2008 ) and in 2009 (Kastberger et al 2011b , 2012 , 2013a , b ; Weihmann et al 2012 ), but in November 2010 a single nest was selected for the much broader in-depth investigation described in this paper. This approximately 3-week-old nest was attached to a hotel balcony (Fig.…”

Section: Methodsmentioning

confidence: 99%

“…Giant honeybees have evolved shimmering behaviour for collective defence (Seeley et al 1982 ; Kastberger et al 2011a ; Weihmann et al 2012 ). Visual threats provoke patterns reminiscent of Mexican waves, which propagate with a characteristic velocity and in a controlled direction over the surface of a giant honeybee nest (Kastberger et al 2012 , 2013a , b ).…”

Section: Introductionmentioning

confidence: 99%

Giant honeybees (Apis dorsata) mob wasps away from the nest by directed visual patterns

Kastberger

Zierler

et al. 2014

Naturwissenschaften

Self Cite

The open nesting behaviour of giant honeybees (Apis dorsata) accounts for the evolution of a series of defence strategies to protect the colonies from predation. In particular, the concerted action of shimmering behaviour is known to effectively confuse and repel predators. In shimmering, bees on the nest surface flip their abdomens in a highly coordinated manner to generate Mexican wave-like patterns. The paper documents a further-going capacity of this kind of collective defence: the visual patterns of shimmering waves align regarding their directional characteristics with the projected flight manoeuvres of the wasps when preying in front of the bees’ nest. The honeybees take here advantage of a threefold asymmetry intrinsic to the prey–predator interaction: (a) the visual patterns of shimmering turn faster than the wasps on their flight path, (b) they “follow” the wasps more persistently (up to 100 ms) than the wasps “follow” the shimmering patterns (up to 40 ms) and (c) the shimmering patterns align with the wasps’ flight in all directions at the same strength, whereas the wasps have some preference for horizontal correspondence. The findings give evidence that shimmering honeybees utilize directional alignment to enforce their repelling power against preying wasps. This phenomenon can be identified as predator driving which is generally associated with mobbing behaviour (particularly known in selfish herds of vertebrate species), which is, until now, not reported in insects.Electronic supplementary materialThe online version of this article (doi:10.1007/s00114-014-1220-0) contains supplementary material, which is available to authorized users.