A batch of JEB papers

We’ve had a nice batch of JEB papers all appear recently. So here they are all together.

Firstly, Barron and Plath discuss how the waggle dance of honeybees might be controlled in the neural circuits of the bee brain. This is fascinating stuff as it is one of the great mysteries in insect behaviour how bees can move information between different frames of reference. Secondly, Lobecke et al. look at the learning flights of bumblebees via an analysis of the fine-grain motor motifs. They find that learning flights don’t show the expected consistency of structure that might have been assumed to be useful for learning the location of the nest entrance. This variability leads the authors to suggest that the bee is acquiring a dynamic snapshot, as presumably a static snapshot would require more consistency across the views ‘acquired’ during the learning flight. Finally, a paper from us at Sussex. We investigated the relationship between Path Integration and visual information after first describing how PI controlled paths show a systematic speed variation, with higher speeds shown at greater distances from the next. We found that at lower speeds (i.e. nearer the nest) visual cues (either familiar or novel) have a greater impact on ants paths.

Barron, A. B., & Plath, J. A. (2017). The evolution of honey bee dance communication: a mechanistic perspective. Journal of Experimental Biology, 220(23), 4339-4346.

Lobecke, A., Kern, R., & Egelhaaf, M. (2017). Taking a goal-centred dynamic snapshot as a possibility for local homing in initially naïve bumblebees. Journal of Experimental Biology, jeb-168674.

Buehlmann, C., Fernandes, A. S. D., & Graham, P. (2017). The interaction of path integration and terrestrial visual cues in navigating desert ants: what can we learn from path characteristics?. Journal of Experimental Biology, jeb-167304.

Categories: Papers from 2017

The birds and the bees

Well, I’ve been waiting for a good while to use that BLOG title and now the perfect paper has come along. Pritchard et al. discuss the similarities in foraging ecology between bees and hummingbirds, which are strong enough to suggest that we may see convergent evolution in the cognitive adaptations for foraging and spatial behaviour. Furthermore, and particularly nice to see for us, the authors discuss the ways in which conceptual and technical advances from insect navigation research are now, finally, having traction in studies of birds.

Pritchard, D. J., Ramos, M. T., Muth, F., & Healy, S. D. (2017). Treating hummingbirds as feathered bees: a case of ethological cross-pollination. Biology letters, 13(12), 20170610.

Categories: Papers from 2017

Ant-bots and compass sensors

A fundamental principle behind this BLOG is that the study of insect spatial behaviour is inherently interesting to roboticists. This is because the sensors and behaviours are tuned for navigation and little else. Following conference season, we have a bumper crop of such biorobotic projects. Two papers from the Marseille team detail the development of a hexapod robot and then the deployment of a compass sensor inspired by the specialised ommatidia in the dorsal rim area of insect eyes. Wolfgang Stürzl also presents the development of a new compass sensor. In this case inspired by the ocelli of insects, which are 3 simple dorsally facing ‘eyes’.

Julien Dupeyroux, Julien Diperi, Marc Boyron, Stéphane Viollet, Julien Serres. A novel insect-inspired optical compass sensor for a hexapod walking robot. IROS 2017 – IEEE/RSJ International Conference on Intelligent Robots and Systems, Sep 2017, Vancouver, Canada.

Dupeyroux, J., Passault, G., Ruffier, F., Viollet, S., & Serres, J. (2017). Hexabot: a small 3D-printed six-legged walking robot designed for desert ant-like navigation tasks. In IFAC Word Congress 2017.

W. Stürzl (2017). A Lightweight Single-Camera Polarization Compass With Covariance Estimation. In Proceedings of the IEEE International Conference on Computer Vision (ICCV), pp. 5353-5361

Categories: Papers from 2017

From the field to VR (and back again?)

The last month has seen the publication of a pair of papers describing open-source tools solving two key problems faced by field experimentalists. Firstly, at the recent ICCV2017 workshop on animal tracking, Risse et al presented Habitracks – an open-source software to automatically track small animals in videos recorded in natural habitats. Fully automatic and highly accurate tracking was shown for a number of species including ants, bees, and dung-beetles in video recording from field experiments. In the second work, the same team present Habitat3D, a software tool that automatically integrates multiple laser scans of natural environments into a single photorealistic mesh. This then allows easy reconstruction of animal views using standard graphics packages or the presentation of realistic VR worlds to insects in track-ball experiments. Combined these tools bring us a step closer to realising the goal of reconstructing the actual visual perspective of animals allowing validation of hypothesis in realistic environments.

Risse, B., Mangan, M., Del Pero, L., & Webb, B. (2017). Visual Tracking of Small Animals in Cluttered Natural Environments Using a Freely Moving Camera. The IEEE International Conference on Computer Vision (ICCV)(pp. 2840-2849).

Risse, B., Mangan, M., Stürzl, W., & Webb, B. (2018). Software to convert terrestrial LiDAR scans of natural environments into photorealistic meshes. Environmental Modelling & Software, 99, 88-100.

Categories: Papers from 2017

Learning about sky compasses

The early days of an ant forager’s life present a succession of learning challenges. Ants must learn about the ephemeris function for their part of the world and the current time of year. They also have to learn about the visual surrounds of their nest. Learning walks with specific structure are key to this. A key part of learning walks in desert ant species from visually rich environments is that ants fixate the nest at specific points. Here, Grob et al look at how these precise fixations might depend on celestial information. Interestingly, the precision of fixations is maintained even when polarisation and sun position information is removed. However, natural polarization information via the UV channel is necessary for the triggering of brain changes in these new foragers. Learning walks with natural polarisation and UV lead to brain changes in both central complex and the visual input region of the mushroom body. This gives some clues as to the neural underpinning of early ‘career’ learning in new foragers.

Grob R, Fleischmann PN, Grübel K, Wehner R and Rössler W (2017) The Role of Celestial Compass Information in Cataglyphis Ants during Learning Walks and for Neuroplasticity in the Central Complex and Mushroom Bodies. Front. Behav. Neurosci. 11:226. doi: 10.3389/fnbeh.2017.00226

Categories: Papers from 2017

Neural control of flight

With each passing month, we learn more about the neural underpinnings of navigation and orientation behaviours. Here is another piece in the jigsaw:

Abstract: The impressive repertoire of honeybee visually guided behaviors, and their ability to learn has made them an important tool for elucidating the visual basis of behavior. Like other insects, bees perform optomotor course correction to optic flow, a response that is dependent on the spatial structure of the visual environment. However, bees can also distinguish the speed of image motion during forward flight and landing, as well as estimate flight distances (odometry), irrespective of the visual scene. The neural pathways underlying these abilities are unknown. Here we report on a cluster of descending neurons (DNIIIs) that are shown to have the directional tuning properties necessary for detecting image motion during forward flight and landing on vertical surfaces. They have stable firing rates during prolonged periods of stimulation and respond to a wide range of image speeds, making them suitable to detect image flow during flight behaviors. While their responses are not strictly speed tuned, the shape and amplitudes of their speed tuning functions are resistant to large changes in spatial frequency. These cells are prime candidates not only for the control of flight speed and landing, but also the basis of a neural ‘front end’ of the honeybee’s visual odometer.

Ibbotson, M. R., Hung, Y. S., Meffin, H., Boeddeker, N., & Srinivasan, M. V. (2017). Neural basis of forward flight control and landing in honeybees. Scientific Reports (Nature Publisher Group), 7, 1-15.

Categories: Papers from 2017

Do ants learn what’s unfamiliar?

Experiments with a variety of ant species have shown that ants displaced away from a familiar feeder will follow a Path Integration defined direction for only a portion of the home vector before beginning a systematic search. This behaviour is more pronounced in species living in cluttered environments. In this paper, Schwarz et al., look at the behaviour of naive and experienced ants in a similar situation. As expected the experienced ants only follow a portion of their PI defined route before searching. However, naive ants follow PI for significantly longer, thus demonstrating that the pattern of following a portion of PI indicated home vectors before search is not a species level innate bias, but depends on visual experience. The authors suggest that experienced ants are better able to identify an unfamiliar location and therefore know to switch to search more rapidly. An alternative is that individuals with visual experience may be trying to apply those memories, but unsuccessfully in the unfamiliar location. This faulty visual guidance will not influence PI defined paths for long home vectors when PI is weighted strongly, but may lead to a disorganised (search-like) paths for weaker PI vectors later in the path.

Schwarz, S., Wystrach, A., & Cheng, K. (2017). Ants’ navigation in an unfamiliar environment is influenced by their experience of a familiar route. Scientific Reports, 7(1), 14161.

Categories: Papers from 2017