The Reciprocity of Environment and Action in Self-Righting Beetles: The Textures of the Ground and an Object, and the Claws

Abstract

The process of self-righting to recover the orientation to the ground was observed in Japanese beetles. Video observation of self-righting processes in an indoor environment suggested that the properties of the environment that afforded self-righting were (a) texture of the substrate surface; (b) a soft, deformable object that can be held on to and swung by a beetle; and (c) the gap between the substrate and a hard object that afforded a spiral-like rotation of a beetle. Incorporating such properties, self-righting of beetles emerged as 3 kinds of environment-action systems: a "surface texture/leg tip system"; a "soft object held by limbs/round back on the ground system"; and a "hard object/multiple limbs/round back on the ground system." Controlled experiments on multiple individuals further revealed that what is meaningful to self-righting is not a local, discrete texture of a surface but a higher order combination of textures of surfaces surrounding the animal. Based on the results, flexibility of action, properties of the environment that afford beetles' orientation to the surroundings, and the features of the distal tip of the limbs of beetles, as well as the reciprocity among them, are discussed.

Propelling and perturbing appendages together facilitate strenuous ground self-righting

“…Although only demonstrated in a model system, the potential energy landscape approach can in principle be applied to more complex and different self-righting behaviors, as well as on ground of different properties ( Sasaki and Nonaka, 2016 ), to understand how propelling and perturbing effects work together. For example, as the ground becomes more rugged with larger asperities, the landscape becomes more rugged with more attractive basins ( Figure 8 , Figure 8—video 1 ).…”

Mechanical principles of dynamic terrestrial self-righting using wings

“…Inspired by our successful design and discovery of the principles of winged dynamic selfrighting, we will continue to develop new robot prototypes that will have integrated ability to both traverse obstacles [24] and self-right if flipped over. In addition, we will continue to systematically test robots as physical models [73] to further elucidate the mechanisms of dynamic self-righting, such as whether body vibrations induced by leg flailing help animals access lower energy barrier locomotor pathways [24], how animals use legs to recover from under-and overrighting [63], and how terrain topology [49,74] and mechanics [24,74] affect self-righting. Further, measurements of ground reaction forces and multi-body dynamics simulations [33] can provide more insights into the dynamics of the rising phase of winged self-righting.…”

Cockroaches use diverse strategies to self-right on the ground

“…4), as well as body yawing and deformation and various body and appendage behaviors (Fig. S1, S3), which seemed not beneficial here, may allow the animal to self-right novel ways in natural environments by interacting with slopes, uneven and deformable surfaces, or nearby objects (Golubovic et al, 2013;Peng et al, 2015;Sasaki and Nonaka, 2016). Third, even the seemingly stochastic and unpredictable motion over consecutive attempts may be an adaptation to heterogeneous, stochastic natural environments (Kaspari and Weiser, 1999).…”

“…Our quantification of self-righting on a flat, rigid, low-friction surface represents a very challenging scenario. Future experiments should test and model how animals interact with slopes, uneven and deformable surfaces, or nearby objects (Golubovic et al, 2013;Peng et al, 2015;Sasaki and Nonaka, 2016) using potential energy landscapes to reveal principles of self-righting in nature. In addition, given our finding that rolling facilitates self-righting by lowering the potential energy barrier, we speculate that searching to grasp the ground or nearby objects (Frantsevich, 2004;Sasaki and Nonaka, 2016), leg flailing American cockroach using the legs.…”