1
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Shirazi S, Higham TE. How do fish miss? Attack strategies of threespine stickleback capturing non-evasive prey. J Exp Biol 2024; 227:jeb247814. [PMID: 39369304 PMCID: PMC11586519 DOI: 10.1242/jeb.247814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 09/23/2024] [Indexed: 10/07/2024]
Abstract
Most predators rely on capturing prey for survival, yet failure is common. Failure is often attributed to prey evasion, but predator miscalculation and/or inaccuracy may also drive an unsuccessful event. We addressed the latter using threespine stickleback as predators and bloodworms (non-evasive) as prey. High-speed videography of the entire attack allowed us to determine the strike tactics leading to successful or missed strikes. We analyzed movements and morphological traits from 57 individuals. Our results reveal that kinematics drive the strike outcome and that failed strikes primarily arise from incorrect timing of mouth opening, often beginning too far from the prey for suction to be effective. This likely stems from the lack of integration between locomotion and feeding systems. Our study begins to unravel the important link between behavior and success in fish feeding.
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Affiliation(s)
- Seth Shirazi
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - Timothy E. Higham
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, Riverside, CA 92521, USA
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2
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Cuff JP, Labonte D, Windsor FM. Understanding Trophic Interactions in a Warming World by Bridging Foraging Ecology and Biomechanics with Network Science. Integr Comp Biol 2024; 64:306-321. [PMID: 38872009 PMCID: PMC11406160 DOI: 10.1093/icb/icae070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 06/04/2024] [Accepted: 06/08/2024] [Indexed: 06/15/2024] Open
Abstract
Climate change will disrupt biological processes at every scale. Ecosystem functions and services vital to ecological resilience are set to shift, with consequences for how we manage land, natural resources, and food systems. Increasing temperatures cause morphological shifts, with concomitant implications for biomechanical performance metrics crucial to trophic interactions. Biomechanical performance, such as maximum bite force or running speed, determines the breadth of resources accessible to consumers, the outcome of interspecific interactions, and thus the structure of ecological networks. Climate change-induced impacts to ecosystem services and resilience are therefore on the horizon, mediated by disruptions of biomechanical performance and, consequently, trophic interactions across whole ecosystems. Here, we argue that there is an urgent need to investigate the complex interactions between climate change, biomechanical traits, and foraging ecology to help predict changes to ecological networks and ecosystem functioning. We discuss how these seemingly disparate disciplines can be connected through network science. Using an ant-plant network as an example, we illustrate how different data types could be integrated to investigate the interaction between warming, bite force, and trophic interactions, and discuss what such an integration will achieve. It is our hope that this integrative framework will help to identify a viable means to elucidate previously intractable impacts of climate change, with effective predictive potential to guide management and mitigation.
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Affiliation(s)
- Jordan P Cuff
- School of Natural and Environmental Sciences, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - David Labonte
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
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3
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Schwarz MB, O'Carroll DC, Evans BJE, Fabian JM, Wiederman SD. Localized and Long-Lasting Adaptation in Dragonfly Target-Detecting Neurons. eNeuro 2024; 11:ENEURO.0036-24.2024. [PMID: 39256041 PMCID: PMC11419696 DOI: 10.1523/eneuro.0036-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 08/03/2024] [Accepted: 08/28/2024] [Indexed: 09/12/2024] Open
Abstract
Some visual neurons in the dragonfly (Hemicordulia tau) optic lobe respond to small, moving targets, likely underlying their fast pursuit of prey and conspecifics. In response to repetitive targets presented at short intervals, the spiking activity of these "small target motion detector" (STMD) neurons diminishes over time. Previous experiments limited this adaptation by including intertrial rest periods of varying durations. However, the characteristics of this effect have never been quantified. Here, using extracellular recording techniques lasting for several hours, we quantified both the spatial and temporal properties of STMD adaptation. We found that the time course of adaptation was variable across STMD units. In any one STMD, a repeated series led to more rapid adaptation, a minor accumulative effect more akin to habituation. Following an adapting stimulus, responses recovered quickly, though the rate of recovery decreased nonlinearly over time. We found that the region of adaptation is highly localized, with targets displaced by ∼2.5° eliciting a naive response. Higher frequencies of target stimulation converged to lower levels of sustained response activity. We determined that adaptation itself is a target-tuned property, not elicited by moving bars or luminance flicker. As STMD adaptation is a localized phenomenon, dependent on recent history, it is likely to play an important role in closed-loop behavior where a target is foveated in a localized region for extended periods of the pursuit duration.
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Affiliation(s)
- Matthew B Schwarz
- School of Biomedicine, The University of Adelaide, Adelaide, South Australia 5001, Australia
| | | | - Bernard J E Evans
- School of Biomedicine, The University of Adelaide, Adelaide, South Australia 5001, Australia
| | - Joseph M Fabian
- School of Biomedicine, The University of Adelaide, Adelaide, South Australia 5001, Australia
| | - Steven D Wiederman
- School of Biomedicine, The University of Adelaide, Adelaide, South Australia 5001, Australia
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4
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Kodama T, Sakamoto SH, Mori A. Cold kiss still hot: limited temperature effects on envenomation performance in predatory strikes of a Japanese pit viper ( Gloydius blomhoffii). Proc Biol Sci 2024; 291:20240719. [PMID: 39079665 PMCID: PMC11288664 DOI: 10.1098/rspb.2024.0719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/24/2024] [Accepted: 07/04/2024] [Indexed: 08/03/2024] Open
Abstract
Understanding how environmental factors affect the performance of predators can provide profound insights into predator-prey interactions from evolutionary and ecological perspectives and the global distributional patterns of each taxon. Almost all venomous predators are ectotherms, with muscle contraction properties depending on temperature. For predators having venom transportation systems driven by muscle contraction, temperature may have quite large effects on envenomation performance for prey subjugation. Here, we used videography and enzyme-linked immunosorbent assay to examine thermal effects on envenomation kinematics and venom expenditure in predatory strikes of a venomous snake, the Mamushi Gloydius blomhoffii, to its main rodent prey at various body temperatures under both field and laboratory experimental conditions. Unexpectedly, we found that the thermal effects on envenomation performance are limited over nearly the entire ecologically relevant range of temperature (from 13.2°C to 26.2°C). Although temperature statistically significantly affected the mass of venom injected under field conditions, temperature explained only a minor proportion of the variation in venom expenditure. These findings suggest that the Mamushi is able to maintain prey subjugation performance across a wide range of temperatures, which is highly advantageous for ectothermic predators. Further studies should examine the underlying mechanisms of the limited thermal effects and their ubiquity across venomous predators.
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Affiliation(s)
- Tomonori Kodama
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto606-8502, Japan
| | - Shinsuke H. Sakamoto
- Faculty of Agriculture, University of Miyazaki, Miyazaki889-2192, Japan
- Center for Animal Disease Control, University of Miyazaki, Miyazaki889-2192, Japan
| | - Akira Mori
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto606-8502, Japan
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5
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Ke X, Yong H, Xu F, Ding H, Wu Z. Stenus-inspired, swift, and agile untethered insect-scale soft propulsors. Nat Commun 2024; 15:1491. [PMID: 38374180 PMCID: PMC10876683 DOI: 10.1038/s41467-024-45997-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/09/2024] [Indexed: 02/21/2024] Open
Abstract
Mimicking living creatures, soft robots exhibit incomparable adaptability and various attractive new features. However, untethered insect-scale soft robots are often plagued with inferior controllability and low kinetic performance. Systematically inspired by the swift swingable abdomen, conducting canals for secretion transport, and body setae of Stenus comma, together with magnetic-induced fast-transformed postures, herein, we present a swift, agile untethered millimetre-scale soft propulsor propelling on water. The demonstrated propulsor, with a body length (BL) of 3.6 mm, achieved a recorded specific speed of ~201 BL/s and acceleration of ~8,372 BL/s2. The comprehensive kinetic performance of this propulsor surpasses those of previous ones at similar scales by several orders. Notably, we discovered momentum-transfer-induced over-biological on-demand braking (deceleration ~-5,010 BL/s2) and elucidated the underlying hydrodynamics. This work offers new insights into systematically bio-inspired artificial insect-scale soft robots, enabling them to push boundaries in performance, and potentially revolutionizing robot design, optimization, and control paradigms.
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Affiliation(s)
- Xingxing Ke
- State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Haochen Yong
- State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Fukang Xu
- State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Han Ding
- State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhigang Wu
- State Key Laboratory of Intelligent Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
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6
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Ogawa Y, Nicholas S, Thyselius M, Leibbrandt R, Nowotny T, Knight JC, Nordström K. Descending neurons of the hoverfly respond to pursuits of artificial targets. Curr Biol 2023; 33:4392-4404.e5. [PMID: 37776861 DOI: 10.1016/j.cub.2023.08.091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/11/2023] [Accepted: 08/31/2023] [Indexed: 10/02/2023]
Abstract
Many animals use motion vision information to control dynamic behaviors. Predatory animals, for example, show an exquisite ability to detect rapidly moving prey, followed by pursuit and capture. Such target detection is not only used by predators but is also important in conspecific interactions, such as for male hoverflies defending their territories against conspecific intruders. Visual target detection is believed to be subserved by specialized target-tuned neurons found in a range of species, including vertebrates and arthropods. However, how these target-tuned neurons respond to actual pursuit trajectories is currently not well understood. To redress this, we recorded extracellularly from target-selective descending neurons (TSDNs) in male Eristalis tenax hoverflies. We show that they have dorso-frontal receptive fields with a preferred direction up and away from the visual midline. We reconstructed visual flow fields as experienced during pursuits of artificial targets (black beads). We recorded TSDN responses to six reconstructed pursuits and found that each neuron responded consistently at remarkably specific time points but that these time points differed between neurons. We found that the observed spike probability was correlated with the spike probability predicted from each neuron's receptive field and size tuning. Interestingly, however, the overall response rate was low, with individual neurons responding to only a small part of each reconstructed pursuit. In contrast, the TSDN population responded to substantially larger proportions of the pursuits but with lower probability. This large variation between neurons could be useful if different neurons control different parts of the behavioral output.
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Affiliation(s)
- Yuri Ogawa
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Sarah Nicholas
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Malin Thyselius
- Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden; School of Medical Sciences, Faculty of Medicine and Health, Örebro University, Örebro 701 82, Sweden
| | - Richard Leibbrandt
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Thomas Nowotny
- School of Engineering and Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - James C Knight
- School of Engineering and Informatics, University of Sussex, Brighton BN1 9QJ, UK
| | - Karin Nordström
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia; Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden.
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7
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Hansen MJ, Domenici P, Bartashevich P, Burns A, Krause J. Mechanisms of group-hunting in vertebrates. Biol Rev Camb Philos Soc 2023; 98:1687-1711. [PMID: 37199232 DOI: 10.1111/brv.12973] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/19/2023]
Abstract
Group-hunting is ubiquitous across animal taxa and has received considerable attention in the context of its functions. By contrast much less is known about the mechanisms by which grouping predators hunt their prey. This is primarily due to a lack of experimental manipulation alongside logistical difficulties quantifying the behaviour of multiple predators at high spatiotemporal resolution as they search, select, and capture wild prey. However, the use of new remote-sensing technologies and a broadening of the focal taxa beyond apex predators provides researchers with a great opportunity to discern accurately how multiple predators hunt together and not just whether doing so provides hunters with a per capita benefit. We incorporate many ideas from collective behaviour and locomotion throughout this review to make testable predictions for future researchers and pay particular attention to the role that computer simulation can play in a feedback loop with empirical data collection. Our review of the literature showed that the breadth of predator:prey size ratios among the taxa that can be considered to hunt as a group is very large (<100 to >102 ). We therefore synthesised the literature with respect to these predator:prey ratios and found that they promoted different hunting mechanisms. Additionally, these different hunting mechanisms are also related to particular stages of the hunt (search, selection, capture) and thus we structure our review in accordance with these two factors (stage of the hunt and predator:prey size ratio). We identify several novel group-hunting mechanisms which are largely untested, particularly under field conditions, and we also highlight a range of potential study organisms that are amenable to experimental testing of these mechanisms in connection with tracking technology. We believe that a combination of new hypotheses, study systems and methodological approaches should help push the field of group-hunting in new directions.
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Affiliation(s)
- Matthew J Hansen
- Fish Biology, Fisheries and Aquaculture, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
| | - Paolo Domenici
- IBF-CNR, Consiglio Nazionale delle Ricerche, Area di Ricerca San Cataldo, Via G. Moruzzi No. 1, Pisa, 56124, Italy
- IAS-CNR, Località Sa Mardini, Torregrande, Oristano, 09170, Italy
| | - Palina Bartashevich
- Faculty of Life Science, Humboldt-Universität zu Berlin, Invalidenstrasse 42, Berlin, 10115, Germany
- Cluster of Excellence "Science of Intelligence," Technical University of Berlin, Marchstr. 23, Berlin, 10587, Germany
| | - Alicia Burns
- Faculty of Life Science, Humboldt-Universität zu Berlin, Invalidenstrasse 42, Berlin, 10115, Germany
- Cluster of Excellence "Science of Intelligence," Technical University of Berlin, Marchstr. 23, Berlin, 10587, Germany
| | - Jens Krause
- Fish Biology, Fisheries and Aquaculture, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
- Faculty of Life Science, Humboldt-Universität zu Berlin, Invalidenstrasse 42, Berlin, 10115, Germany
- Cluster of Excellence "Science of Intelligence," Technical University of Berlin, Marchstr. 23, Berlin, 10587, Germany
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8
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Bortoni A, Swartz SM, Vejdani H, Corcoran AJ. Strategic predatory pursuit of the stealthy, highly manoeuvrable, slow flying bat Corynorhinus townsendii. Proc Biol Sci 2023; 290:20230138. [PMID: 37357862 PMCID: PMC10291723 DOI: 10.1098/rspb.2023.0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 06/06/2023] [Indexed: 06/27/2023] Open
Abstract
A predator's capacity to catch prey depends on its ability to navigate its environment in response to prey movements or escape behaviour. In predator-prey interactions that involve an active chase, pursuit behaviour can be studied as the collection of rules that dictate how a predator should steer to capture prey. It remains unclear how variable this behaviour is within and across species since most studies have detailed the pursuit behaviour of high-speed, open-area foragers. In this study, we analyse the pursuit behaviour in 44 successful captures by Corynorhinus townsendii, Townsend's big-eared bat (n = 4). This species forages close to vegetation using slow and highly manoeuvrable flight, which contrasts with the locomotor capabilities and feeding ecologies of other taxa studied to date. Our results indicate that this species relies on an initial stealthy approach, which is generally sufficient to capture prey (32 out of 44 trials). In cases where the initial approach is not sufficient to perform a capture attempt (12 out of 44 trials), C. townsendii continues its pursuit by reacting to prey movements in a manner best modelled with a combination of pure pursuit, or following prey directly, and proportional navigation, or moving to an interception point.
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Affiliation(s)
- Alberto Bortoni
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
| | - Sharon M. Swartz
- Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA
- School of Engineering, Brown University, Providence, RI 02912, USA
| | - Hamid Vejdani
- Mechanical, Robotics, and Industrial Engineering, Lawrence Technological University, Southfield, MI 48075, USA
| | - Aaron J. Corcoran
- Department of Biology, University of Colorado, Colorado Springs, CO 80918, USA
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9
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Provini P, Camp AL, Crandell KE. Emerging biological insights enabled by high-resolution 3D motion data: promises, perspectives and pitfalls. J Exp Biol 2023; 226:286825. [PMID: 36752301 PMCID: PMC10038148 DOI: 10.1242/jeb.245138] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Deconstructing motion to better understand it is a key prerequisite in the field of comparative biomechanics. Since Marey and Muybridge's work, technical constraints have been the largest limitation to motion capture and analysis, which, in turn, limited what kinds of questions biologists could ask or answer. Throughout the history of our field, conceptual leaps and significant technical advances have generally worked hand in hand. Recently, high-resolution, three-dimensional (3D) motion data have become easier to acquire, providing new opportunities for comparative biomechanics. We describe how adding a third dimension of information has fuelled major paradigm shifts, not only leading to a reinterpretation of long-standing scientific questions but also allowing new questions to be asked. In this paper, we highlight recent work published in Journal of Experimental Biology and influenced by these studies, demonstrating the biological breakthroughs made with 3D data. Although amazing opportunities emerge from these technical and conceptual advances, high-resolution data often come with a price. Here, we discuss challenges of 3D data, including low-throughput methodology, costly equipment, low sample sizes, and complex analyses and presentation. Therefore, we propose guidelines for how and when to pursue 3D high-resolution data. We also suggest research areas that are poised for major new biological advances through emerging 3D data collection.
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Affiliation(s)
- Pauline Provini
- Université Paris Cité, Inserm, System Engineering and Evolution Dynamics, F-75004 Paris, France
- Learning Planet Institute, F-75004 Paris, France
- Département Adaptations du Vivant, UMR 7179 CNRS/Muséum National d'Histoire Naturelle, F-75005 Paris, France
| | - Ariel L Camp
- Department of Musculoskeletal and Ageing Science, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool L78TX, UK
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10
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Thyselius M, Ogawa Y, Leibbrandt R, Wardill TJ, Gonzalez-Bellido PT, Nordström K. Hoverfly (Eristalis tenax) pursuit of artificial targets. J Exp Biol 2023; 226:289473. [PMID: 36695720 PMCID: PMC10088529 DOI: 10.1242/jeb.244895] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/18/2023] [Indexed: 01/26/2023]
Abstract
The ability to visualize small moving objects is vital for the survival of many animals, as these could represent predators or prey. For example, predatory insects, including dragonflies, robber flies and killer flies, perform elegant, high-speed pursuits of both biological and artificial targets. Many non-predatory insects, including male hoverflies and blowflies, also pursue targets during territorial or courtship interactions. To date, most hoverfly pursuits have been studied outdoors. To investigate hoverfly (Eristalis tenax) pursuits under more controlled settings, we constructed an indoor arena that was large enough to encourage naturalistic behavior. We presented artificial beads of different sizes, moving at different speeds, and filmed pursuits with two cameras, allowing subsequent 3D reconstruction of the hoverfly and bead position as a function of time. We show that male E. tenax hoverflies are unlikely to use strict heuristic rules based on angular size or speed to determine when to start pursuit, at least in our indoor setting. We found that hoverflies pursued faster beads when the trajectory involved flying downwards towards the bead. Furthermore, we show that target pursuit behavior can be broken down into two stages. In the first stage, the hoverfly attempts to rapidly decreases the distance to the target by intercepting it at high speed. During the second stage, the hoverfly's forward speed is correlated with the speed of the bead, so that the hoverfly remains close, but without catching it. This may be similar to dragonfly shadowing behavior, previously coined 'motion camouflage'.
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Affiliation(s)
- Malin Thyselius
- Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden
| | - Yuri Ogawa
- Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Richard Leibbrandt
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Trevor J Wardill
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN 55108, USA
| | | | - Karin Nordström
- Department of Medical Cell Biology, Uppsala University, 75123 Uppsala, Sweden.,Flinders Health and Medical Research Institute, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
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11
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Barendregt NW, Gold JI, Josić K, Kilpatrick ZP. Normative decision rules in changing environments. eLife 2022; 11:e79824. [PMID: 36282065 PMCID: PMC9754630 DOI: 10.7554/elife.79824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 10/20/2022] [Indexed: 11/13/2022] Open
Abstract
Models based on normative principles have played a major role in our understanding of how the brain forms decisions. However, these models have typically been derived for simple, stable conditions, and their relevance to decisions formed under more naturalistic, dynamic conditions is unclear. We previously derived a normative decision model in which evidence accumulation is adapted to fluctuations in the evidence-generating process that occur during a single decision (Glaze et al., 2015), but the evolution of commitment rules (e.g. thresholds on the accumulated evidence) under dynamic conditions is not fully understood. Here, we derive a normative model for decisions based on changing contexts, which we define as changes in evidence quality or reward, over the course of a single decision. In these cases, performance (reward rate) is maximized using decision thresholds that respond to and even anticipate these changes, in contrast to the static thresholds used in many decision models. We show that these adaptive thresholds exhibit several distinct temporal motifs that depend on the specific predicted and experienced context changes and that adaptive models perform robustly even when implemented imperfectly (noisily). We further show that decision models with adaptive thresholds outperform those with constant or urgency-gated thresholds in accounting for human response times on a task with time-varying evidence quality and average reward. These results further link normative and neural decision-making while expanding our view of both as dynamic, adaptive processes that update and use expectations to govern both deliberation and commitment.
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Affiliation(s)
- Nicholas W Barendregt
- Department of Applied Mathematics, University of Colorado BoulderBoulderUnited States
| | - Joshua I Gold
- Department of Neuroscience, University of PennsylvaniaPhiladelphiaUnited States
| | - Krešimir Josić
- Department of Mathematics, University of HoustonHoustonUnited States
| | - Zachary P Kilpatrick
- Department of Applied Mathematics, University of Colorado BoulderBoulderUnited States
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12
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Lancer BH, Evans BJE, Fabian JM, O'Carroll DC, Wiederman SD. Preattentive facilitation of target trajectories in a dragonfly visual neuron. Commun Biol 2022; 5:829. [PMID: 35982305 PMCID: PMC9388622 DOI: 10.1038/s42003-022-03798-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 08/04/2022] [Indexed: 12/03/2022] Open
Abstract
The ability to pursue targets in visually cluttered and distraction-rich environments is critical for predators such as dragonflies. Previously, we identified Centrifugal Small-Target Motion Detector 1 (CSTMD1), a dragonfly visual neuron likely involved in such target-tracking behaviour. CSTMD1 exhibits facilitated responses to targets moving along a continuous trajectory. Moreover, CSTMD1 competitively selects a single target out of a pair. Here, we conducted in vivo, intracellular recordings from CSTMD1 to examine the interplay between facilitation and selection, in response to the presentation of paired targets. We find that neuronal responses to both individual trajectories of simultaneous, paired targets are facilitated, rather than being constrained to the single, selected target. Additionally, switches in selection elicit suppression which is likely an important attribute underlying target pursuit. However, binocular experiments reveal these results are constrained to paired targets within the same visual hemifield, while selection of a target in one visual hemifield establishes ocular dominance that prevents facilitation or response to contralaterally presented targets. These results reveal that the dragonfly brain preattentively represents more than one target trajectory, to balance between attentional flexibility and resistance against distraction. A dragonfly visual neuron independently facilitates responses to rival targets within the same visual field, mediating selective attention.
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Affiliation(s)
- Benjamin H Lancer
- School of Biomedicine, The University of Adelaide, Adelaide, Australia.
| | - Bernard J E Evans
- School of Biomedicine, The University of Adelaide, Adelaide, Australia
| | - Joseph M Fabian
- School of Biomedicine, The University of Adelaide, Adelaide, Australia
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13
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Responsive robotic prey reveal how predators adapt to predictability in escape tactics. Proc Natl Acad Sci U S A 2022; 119:e2117858119. [PMID: 35658072 PMCID: PMC9191677 DOI: 10.1073/pnas.2117858119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A widespread strategy used by prey animals, seen in insects, mammals, amphibians, crustaceans, fish, and reptiles, is to vary the direction in which they escape when attacked by a predator. This unpredictability is thought to benefit prey by inhibiting predators from predicting the prey’s escape trajectory, but experimental evidence is lacking. Using fish predators repeatedly tested with interactive, robot-controlled prey escaping in the same (predictable) or in random (unpredictable) directions, we find no clear benefit to prey of escaping unpredictably, driven by behavioral counteradaptation by the predators. The benefit of unpredictable escape behavior may depend on whether predators are able to counteract prey escape tactics by flexibly modifying their behavior, or unpredictability may instead be explained biomechanical or sensory constraints. To increase their chances of survival, prey often behave unpredictably when escaping from predators. However, the response of predators to, and hence the effectiveness of, such tactics is unknown. We programmed interactive prey to flee from an approaching fish predator (the blue acara, Andinoacara pulcher) using real-time computer vision and two-wheeled robots that controlled the prey’s movements via magnets. This allowed us to manipulate the prey’s initial escape direction and how predictable it was between successive trials with the same individual predator. When repeatedly exposed to predictable prey, the predators adjusted their behavior before the prey even began to escape: prey programmed to escape directly away were approached more rapidly than prey escaping at an acute angle. These faster approach speeds compensated for a longer time needed to capture such prey during the subsequent pursuit phase. By contrast, when attacking unpredictable prey, the predators adopted intermediate approach speeds and were not sensitive to the prey’s escape angle but instead showed greater acceleration during the pursuit. Collectively, these behavioral responses resulted in the prey’s predictability having no net effect on the time taken to capture prey, suggesting that unpredictable escape behavior may be advantageous to prey in fewer circumstances than originally thought. Rather than minimizing capture times, the predators in our study appear to instead adjust their behavior to maintain an adequate level of performance during prey capture.
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14
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Diurnal and nocturnal mosquitoes escape looming threats using distinct flight strategies. Curr Biol 2022; 32:1232-1246.e5. [DOI: 10.1016/j.cub.2022.01.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/21/2021] [Accepted: 01/12/2022] [Indexed: 11/21/2022]
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15
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Saito K, Nagai H, Suto K, Ogawa N, Seong YA, Tachi T, Niiyama R, Kawahara Y. Insect wing 3D printing. Sci Rep 2021; 11:18631. [PMID: 34650126 PMCID: PMC8516917 DOI: 10.1038/s41598-021-98242-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
Insects have acquired various types of wings over their course of evolution and have become the most successful terrestrial animals. Consequently, the essence of their excellent environmental adaptability and locomotive ability should be clarified; a simple and versatile method to artificially reproduce the complex structure and various functions of these innumerable types of wings is necessary. This study presents a simple integral forming method for an insect-wing-type composite structure by 3D printing wing frames directly onto thin films. The artificial venation generation algorithm based on the centroidal Voronoi diagram, which can be observed in the wings of dragonflies, was used to design the complex mechanical properties of artificial wings. Furthermore, we implemented two representative functions found in actual insect wings: folding and coupling. The proposed crease pattern design software developed based on a beetle hindwing enables the 3D printing of foldable wings of any shape. In coupling-type wings, the forewing and hindwing are connected to form a single large wing during flight; these wings can be stored compactly by disconnecting and stacking them like cicada wings.
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Affiliation(s)
- Kazuya Saito
- Faculty of Design, Kyushu University, Fukuoka, 815-8540, Japan.
| | - Hiroto Nagai
- Graduate School of Engineering, Nagasaki University, Nagasaki, 852-8521, Japan
| | - Kai Suto
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
- Nature Architects Inc., Tokyo, 107-0052, Japan
| | - Naoki Ogawa
- Tokyo University of Agriculture, Kanagawa, 243-0034, Japan
| | - Young Ah Seong
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, 113-8654, Japan
| | - Tomohiro Tachi
- Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
| | - Ryuma Niiyama
- Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, 113-8654, Japan
| | - Yoshihiro Kawahara
- Graduate School of Engineering, The University of Tokyo, Tokyo, 113-8654, Japan
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16
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Liang J, Wu Y, Yim JK, Chen H, Miao Z, Liu H, Liu Y, Liu Y, Wang D, Qiu W, Shao Z, Zhang M, Wang X, Zhong J, Lin L. Electrostatic footpads enable agile insect-scale soft robots with trajectory control. Sci Robot 2021; 6:6/55/eabe7906. [PMID: 34193563 DOI: 10.1126/scirobotics.abe7906] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 06/02/2021] [Indexed: 12/11/2022]
Abstract
Agility and trajectory control are two desirable features for robotics, but they become very challenging for soft robots without rigid structures to support rapid manipulations. Here, a curved piezoelectric thin film driven at its structural resonant frequency is used as the main body of an insect-scale soft robot for its fast translational movements, and two electrostatic footpads are used for its swift rotational motions. These two schemes are simultaneously executed during operations through a simple two-wire connection arrangement. A high relative centripetal acceleration of 28 body length per square second compared with existing robots is realized on a 65-milligram tethered prototype, which is better than those of common insects, including the cockroach. The trajectory manipulation demonstration is accomplished by navigating the robot to pass through a 120-centimeter-long track in a maze within 5.6 seconds. One potential application is presented by carrying a 180-milligram on-board sensor to record a gas concentration route map and to identify the location of the leakage source. The radically simplified analog motion adjustment technique enables the scale-up construction of a 240-milligram untethered robot. Equipped with a payload of 1660 milligrams to include the control circuit, a battery, and photoresistors, the untethered prototype can follow a designated, 27.9-centimeter-long "S"-shaped path in 36.9 seconds. These results validate key performance attributes in achieving both high mobility and agility to emulate living agile insects for the advancements of soft robots.
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Affiliation(s)
- Jiaming Liang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.,Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA.,Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Yichuan Wu
- School of Mechanical and Electrical Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Justin K Yim
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15289, USA
| | - Huimin Chen
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zicong Miao
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Hanxiao Liu
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.,Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Ying Liu
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China
| | - Yixin Liu
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Dongkai Wang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.,Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA.,Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Wenying Qiu
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.,Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA.,Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Zhichun Shao
- Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
| | - Min Zhang
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
| | - Xiaohao Wang
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.,Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
| | - Junwen Zhong
- Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA. .,Department of Electromechanical Engineering, Centre for Artificial Intelligence and Robotics, University of Macau, Macao 999078, China
| | - Liwei Lin
- Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China. .,Berkeley Sensor and Actuator Center, Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
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17
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Cloyed CS, Grady JM, Savage VM, Uyeda JC, Dell AI. The allometry of locomotion. Ecology 2021; 102:e03369. [PMID: 33864262 DOI: 10.1002/ecy.3369] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 01/25/2021] [Accepted: 02/22/2021] [Indexed: 11/07/2022]
Abstract
Organismal locomotion mediates ecological interactions and shapes community dynamics. Locomotion is constrained by intrinsic and environmental factors and integrating these factors should clarify how locomotion affects ecology across scales. We extended general theory based on metabolic scaling and biomechanics to predict the scaling of five locomotor performance traits: routine speed, maximum speed, maximum acceleration, minimum powered turn radius, and angular speed. To test these predictions, we used phylogenetically informed analyses of a new database with 884 species and found support for our quantitative predictions. Larger organisms were faster but less maneuverable than smaller organisms. Routine and maximum speeds scaled with body mass to 0.20 and 0.17 powers, respectively, and plateaued at higher body masses, especially for maximum speed. Acceleration was unaffected by body mass. Minimum turn radius scaled to a 0.19 power, and the 95% CI included our theoretical prediction, as we predicted. Maximum angular speed scaled higher than predicted but in the same direction. We observed universal scaling among locomotor modes for routine and maximum speeds but the intercepts varied; flying organisms were faster than those that swam or ran. Acceleration was independent of size in flying and aquatic taxa but decreased with body mass in land animals, possibly due to the risk of injury large, terrestrial organisms face at high speeds and accelerations. Terrestrial mammals inhabiting structurally simple habitats tended to be faster than those in complex habitats. Despite effects of body size, locomotor mode, and habitat complexity, universal scaling of locomotory performance reveals the general ways organisms move across Earth's complex environments.
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Affiliation(s)
- Carl S Cloyed
- National Great Rivers Research and Education Center, East Alton, Illinois, 62024, USA.,Department of Biology, Washington University of St. Louis, St. Louis, Missouri, 63130, USA.,Dauphin Island Sea Lab, Dauphin Island, Alabama, 36528, USA
| | - John M Grady
- National Great Rivers Research and Education Center, East Alton, Illinois, 62024, USA
| | - Van M Savage
- Department of Biomathematics, David Geffen School of Medicine, University of California, Los Angeles, California, 90024, USA
| | - Josef C Uyeda
- Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, 24061, USA
| | - Anthony I Dell
- National Great Rivers Research and Education Center, East Alton, Illinois, 62024, USA.,Department of Biology, Washington University of St. Louis, St. Louis, Missouri, 63130, USA
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18
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Rossoni S, Fabian ST, Sutton GP, Gonzalez-Bellido PT. Gravity and active acceleration limit the ability of killer flies ( Coenosia attenuata) to steer towards prey when attacking from above. J R Soc Interface 2021; 18:20210058. [PMID: 34034531 PMCID: PMC8150022 DOI: 10.1098/rsif.2021.0058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/27/2021] [Indexed: 11/12/2022] Open
Abstract
Insects that predate aerially usually contrast prey against the sky and attack upwards. However, killer flies (Coenosia attenuata) can attack prey flying below them, performing what we term 'aerial dives'. During these dives, killer flies accelerate up to 36 m s-2. Although the trajectories of the killer fly's dives appear highly variable, proportional navigation explains them, as long as the model has the lateral acceleration limit of a real killer fly. The trajectory's steepness is explained by the initial geometry of engagement; steep attacks result from the killer fly taking off when the target is approaching the predator. Under such circumstances, the killer fly dives almost vertically towards the target, and gravity significantly increases its acceleration. Although killer flies usually time their take-off to minimize flight duration, during aerial dives killer flies cannot reach the lateral accelerations necessary to match the increase in speed caused by gravity. Since a close miss still leads the predator closer to the target, and might even slow the prey down, there may not be a selective pressure for killer flies to account for gravity during aerial dives.
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Affiliation(s)
- S. Rossoni
- Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK
| | - S. T. Fabian
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EL, UK
| | - G. P. Sutton
- School of Life Sciences, University of Lincoln, Lincoln LN6 7TS, UK
| | - P. T. Gonzalez-Bellido
- Department of Ecology, Evolution and Behaviour, University of Minnesota, Saint Paul, MN 55108, USA
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19
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Leitch KJ, Ponce FV, Dickson WB, van Breugel F, Dickinson MH. The long-distance flight behavior of Drosophila supports an agent-based model for wind-assisted dispersal in insects. Proc Natl Acad Sci U S A 2021; 118:e2013342118. [PMID: 33879607 PMCID: PMC8092610 DOI: 10.1073/pnas.2013342118] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Despite the ecological importance of long-distance dispersal in insects, its mechanistic basis is poorly understood in genetic model species, in which advanced molecular tools are readily available. One critical question is how insects interact with the wind to detect attractive odor plumes and increase their travel distance as they disperse. To gain insight into dispersal, we conducted release-and-recapture experiments in the Mojave Desert using the fruit fly, Drosophila melanogaster We deployed chemically baited traps in a 1 km radius ring around the release site, equipped with cameras that captured the arrival times of flies as they landed. In each experiment, we released between 30,000 and 200,000 flies. By repeating the experiments under a variety of conditions, we were able to quantify the influence of wind on flies' dispersal behavior. Our results confirm that even tiny fruit flies could disperse ∼12 km in a single flight in still air and might travel many times that distance in a moderate wind. The dispersal behavior of the flies is well explained by an agent-based model in which animals maintain a fixed body orientation relative to celestial cues, actively regulate groundspeed along their body axis, and allow the wind to advect them sideways. The model accounts for the observation that flies actively fan out in all directions in still air but are increasingly advected downwind as winds intensify. Our results suggest that dispersing insects may strike a balance between the need to cover large distances while still maintaining the chance of intercepting odor plumes from upwind sources.
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Affiliation(s)
- Katherine J Leitch
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
| | - Francesca V Ponce
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
| | - William B Dickson
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
| | - Floris van Breugel
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
| | - Michael H Dickinson
- Division of Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125
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20
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Biomimetic Drones Inspired by Dragonflies Will Require a Systems Based Approach and Insights from Biology. DRONES 2021. [DOI: 10.3390/drones5020024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Many drone platforms have matured to become nearly optimal flying machines with only modest improvements in efficiency possible. “Chimera” craft combine fixed wing and rotary wing characteristics while being substantially less efficient than both. The increasing presence of chimeras suggests that their mix of vertical takeoff, hover, and more efficient cruise is invaluable to many end users. We discuss the opportunity for flapping wing drones inspired by large insects to perform these mixed missions. Dragonflies particularly are capable of efficiency in all modes of flight. We will explore the fundamental principles of dragonfly flight to allow for a comparison between proposed flapping wing technological solutions and a flapping wing organism. We chart one approach to achieving the next step in drone technology through systems theory and an appreciation of how biomimetics can be applied. New findings in dynamics of flapping, practical actuation technology, wing design, and flight control are presented and connected. We show that a theoretical understanding of flight systems and an appreciation of the detail of biological implementations may be key to achieving an outcome that matches the performance of natural systems. We assert that an optimal flapping wing drone, capable of efficiency in all modes of flight with high performance upon demand, might look somewhat like an abstract dragonfly.
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21
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Lehmann FO, Wang H, Engels T. Vortex trapping recaptures energy in flying fruit flies. Sci Rep 2021; 11:6992. [PMID: 33772058 PMCID: PMC7997922 DOI: 10.1038/s41598-021-86359-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 03/11/2021] [Indexed: 02/01/2023] Open
Abstract
Flapping flight is one of the most costly forms of locomotion in animals. To limit energetic expenditures, flying insects thus developed multiple strategies. An effective mechanism to reduce flight power expenditures is the harvesting of kinetic energy from motion of the surrounding air. We here show an unusual mechanism of energy harvesting in an insect that recaptures the rotational energy of air vortices. The mechanism requires pronounced chordwise wing bending during which the wing surface momentary traps the vortex and transfers its kinetic energy to the wing within less than a millisecond. Numerical and robotic controls show that the decrease in vortex strength is minimal without the nearby wing surface. The measured energy recycling might slightly reduce the power requirements needed for body weight support in flight, lowering the flight costs in animals flying at elevated power demands. An increase in flight efficiency improves flight during aversive manoeuvring in response to predation and long-distance migration, and thus factors that determine the worldwide abundance and distribution of insect populations.
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Affiliation(s)
- Fritz-Olaf Lehmann
- grid.10493.3f0000000121858338Department of Animal Physiology, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany
| | - Hao Wang
- grid.64938.300000 0000 9558 9911Jiangsu Provincial Key Laboratory of Bionic Functional Materials, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, 29 Yudao St., Nanjing, 210016 China
| | - Thomas Engels
- grid.10493.3f0000000121858338Department of Animal Physiology, University of Rostock, Albert-Einstein-Str. 3, 18059 Rostock, Germany
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22
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Jorge JF, Bergbreiter S, Patek SN. Pendulum-based measurements reveal impact dynamics at the scale of a trap-jaw ant. J Exp Biol 2021; 224:jeb.232157. [PMID: 33504588 DOI: 10.1242/jeb.232157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 01/15/2021] [Indexed: 12/21/2022]
Abstract
Small organisms can produce powerful, sub-millisecond impacts by moving tiny structures at high accelerations. We developed and validated a pendulum device to measure the impact energetics of microgram-sized trap-jaw ant mandibles accelerated against targets at 105 m s-2 Trap-jaw ants (Odontomachus brunneus; 19 individuals, 212 strikes) were suspended on one pendulum and struck swappable targets that were either attached to an opposing pendulum or fixed in place. Mean post-impact kinetic energy (energy from a strike converted to pendulum motion) was higher with a stiff target (21.0-21.5 µJ) than with a compliant target (6.4-6.5 µJ). Target mobility had relatively little influence on energy transfer. Mean contact duration of strikes against stiff targets was shorter (3.9-4.5 ms) than against compliant targets (6.2-7.9 ms). Shorter contact duration was correlated with higher post-impact kinetic energy. These findings contextualize and provide an energetic explanation for the diverse, natural uses of trap-jaw ant strikes such as impaling prey, launching away threats and performing mandible-powered jumps. The strong effect of target material on energetic exchange suggests material interactions as an avenue for tuning performance of small, high acceleration impacts. Our device offers a foundation for novel research into the ecomechanics and evolution of tiny biological impacts and their application in synthetic systems.
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Affiliation(s)
- Justin F Jorge
- Biology Department, Duke University, Durham, NC 27708, USA
| | - Sarah Bergbreiter
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - S N Patek
- Biology Department, Duke University, Durham, NC 27708, USA
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23
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Fabian ST, Zhou R, Lin HT. Dragondrop: a novel passive mechanism for aerial righting in the dragonfly. Proc Biol Sci 2021; 288:20202676. [PMID: 33563128 PMCID: PMC7893233 DOI: 10.1098/rspb.2020.2676] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 01/11/2021] [Indexed: 12/20/2022] Open
Abstract
Dragonflies perform dramatic aerial manoeuvres when chasing targets but glide for periods during cruising flights. This makes dragonflies a great system to explore the role of passive stabilizing mechanisms that do not compromise manoeuvrability. We challenged dragonflies by dropping them from selected inverted attitudes and collected 6-degrees-of-freedom aerial recovery kinematics via custom motion capture techniques. From these kinematic data, we performed rigid-body inverse dynamics to reconstruct the forces and torques involved in righting behaviour. We found that inverted dragonflies typically recover themselves with the shortest rotation from the initial body inclination. Additionally, they exhibited a strong tendency to pitch-up with their head leading out of the manoeuvre, despite the lower moment of inertia in the roll axis. Surprisingly, anaesthetized dragonflies could also complete aerial righting reliably. Such passive righting disappeared in recently dead dragonflies but could be partially recovered by waxing their wings to the anaesthetised posture. Our kinematics data, inverse dynamics model and wind-tunnel experiments suggest that the dragonfly's long abdomen and wing posture generate a rotational tendency and passive attitude recovery mechanism during falling. This work demonstrates an aerodynamically stable body configuration in a flying insect and raises new questions in sensorimotor control for small flying systems.
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Affiliation(s)
| | | | - Huai-Ti Lin
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
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24
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López-Incera A, Ried K, Müller T, Briegel HJ. Development of swarm behavior in artificial learning agents that adapt to different foraging environments. PLoS One 2020; 15:e0243628. [PMID: 33338066 PMCID: PMC7748156 DOI: 10.1371/journal.pone.0243628] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/24/2020] [Indexed: 11/25/2022] Open
Abstract
Collective behavior, and swarm formation in particular, has been studied from several perspectives within a large variety of fields, ranging from biology to physics. In this work, we apply Projective Simulation to model each individual as an artificial learning agent that interacts with its neighbors and surroundings in order to make decisions and learn from them. Within a reinforcement learning framework, we discuss one-dimensional learning scenarios where agents need to get to food resources to be rewarded. We observe how different types of collective motion emerge depending on the distance the agents need to travel to reach the resources. For instance, strongly aligned swarms emerge when the food source is placed far away from the region where agents are situated initially. In addition, we study the properties of the individual trajectories that occur within the different types of emergent collective dynamics. Agents trained to find distant resources exhibit individual trajectories that are in most cases best fit by composite correlated random walks with features that resemble Lévy walks. This composite motion emerges from the collective behavior developed under the specific foraging selection pressures. On the other hand, agents trained to reach nearby resources predominantly exhibit Brownian trajectories.
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Affiliation(s)
- Andrea López-Incera
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria
| | - Katja Ried
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria
| | - Thomas Müller
- Fachbereich Philosophie, Universität Konstanz, Konstanz, Germany
| | - Hans J. Briegel
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria
- Fachbereich Philosophie, Universität Konstanz, Konstanz, Germany
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25
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Lancer BH, Evans BJE, Wiederman SD. The visual neuroecology of anisoptera. CURRENT OPINION IN INSECT SCIENCE 2020; 42:14-22. [PMID: 32841784 DOI: 10.1016/j.cois.2020.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/14/2020] [Accepted: 07/15/2020] [Indexed: 06/11/2023]
Abstract
Dragonflies belong to the oldest known lineage of flying animals, found across the globe around streams, ponds and forests. They are insect predators, specialising in ambush attack as aquatic larvae and rapid pursuit as adults. Dragonfly adults hunt amidst swarms in conditions that confuse many predatory species, and exhibit capture rates above 90%. Underlying the performance of such a remarkable predator is a finely tuned visual system capable of tracking targets amidst distractors and background clutter. The dragonfly performs a complex repertoire of flight behaviours, from near-motionless hovering to acute turns at high speeds. Here, we review the optical, neuronal, and behavioural adaptations that underlie the dragonflies' ability to achieve such remarkable predatory success.
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Affiliation(s)
- Benjamin Horatio Lancer
- Adelaide Medical School, The University of Adelaide, Adelaide, 5005 South Australia, Australia
| | | | - Steven D Wiederman
- Adelaide Medical School, The University of Adelaide, Adelaide, 5005 South Australia, Australia.
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26
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Dakin R, Segre PS, Altshuler DL. Individual variation and the biomechanics of maneuvering flight in hummingbirds. J Exp Biol 2020; 223:223/20/jeb161828. [DOI: 10.1242/jeb.161828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ABSTRACT
An animal's maneuverability will determine the outcome of many of its most important interactions. A common approach to studying maneuverability is to force the animal to perform a specific maneuver or to try to elicit maximal performance. Recently, the availability of wider-field tracking technology has allowed for high-throughput measurements of voluntary behavior, an approach that produces large volumes of data. Here, we show how these data allow for measures of inter-individual variation that are necessary to evaluate how performance depends on other traits, both within and among species. We use simulated data to illustrate best practices when sampling a large number of voluntary maneuvers. Our results show how the sample average can be the best measure of inter-individual variation, whereas the sample maximum is neither repeatable nor a useful metric of the true variation among individuals. Our studies with flying hummingbirds reveal that their maneuvers fall into three major categories: simple translations, simple rotations and complex turns. Simple maneuvers are largely governed by distinct morphological and/or physiological traits. Complex turns involve both translations and rotations, and are more subject to inter-individual differences that are not explained by morphology. This three-part framework suggests that different wingbeat kinematics can be used to maximize specific aspects of maneuverability. Thus, a broad explanatory framework has emerged for interpreting hummingbird maneuverability. This framework is general enough to be applied to other types of locomotion, and informative enough to explain mechanisms of maneuverability that could be applied to both animals and bio-inspired robots.
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Affiliation(s)
- R. Dakin
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
| | - P. S. Segre
- Department of Biology, Hopkins Marine Station, Stanford University, Stanford, CA 93950, USA
| | - D. L. Altshuler
- Department of Zoology, University of British Columbia, 4200-6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
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27
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Whitford MD, Freymiller GA, Higham TE, Clark RW. The Effects of Temperature on the Kinematics of Rattlesnake Predatory Strikes in Both Captive and Field Environments. Integr Org Biol 2020; 2:obaa025. [PMID: 33791566 PMCID: PMC7671150 DOI: 10.1093/iob/obaa025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The outcomes of predator-prey interactions between endotherms and ectotherms can be heavily influenced by environmental temperature, owing to the difference in how body temperature affects locomotor performance. However, as elastic energy storage mechanisms can allow ectotherms to maintain high levels of performance at cooler body temperatures, detailed analyses of kinematics are necessary to fully understand how changes in temperature might alter endotherm-ectotherm predator-prey interactions. Viperid snakes are widely distributed ectothermic mesopredators that interact with endotherms both as predator and prey. Although there are numerous studies on the kinematics of viper strikes, surprisingly few have analyzed how this rapid movement is affected by temperature. Here we studied the effects of temperature on the predatory strike performance of rattlesnakes (Crotalus spp.), abundant new world vipers, using both field and captive experimental contexts. We found that the effects of temperature on predatory strike performance are limited, with warmer snakes achieving slightly higher maximum strike acceleration, but similar maximum velocity. Our results suggest that, unlike defensive strikes to predators, rattlesnakes may not attempt to maximize strike speed when attacking prey, and thus the outcomes of predatory strikes may not be heavily influenced by changes in temperature.
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Affiliation(s)
- M D Whitford
- Department of Biology, San Diego State University, San Diego, CA, USA.,Ecology Graduate Group, University of California, Davis, CA, USA
| | - G A Freymiller
- Department of Biology, San Diego State University, San Diego, CA, USA.,Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - T E Higham
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - R W Clark
- Department of Biology, San Diego State University, San Diego, CA, USA.,Chiricahua Desert Museum, Rodeo, NM, USA
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28
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Behavioral and neuronal underpinnings of safety in numbers in fruit flies. Nat Commun 2020; 11:4182. [PMID: 32826882 PMCID: PMC7442810 DOI: 10.1038/s41467-020-17856-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 07/20/2020] [Indexed: 11/08/2022] Open
Abstract
Living in a group allows individuals to decrease their defenses, enabling other beneficial behaviors such as foraging. The detection of a threat through social cues is widely reported, however, the safety cues that guide animals to break away from a defensive behavior and resume alternate activities remain elusive. Here we show that fruit flies display a graded decrease in freezing behavior, triggered by an inescapable threat, with increasing group sizes. Furthermore, flies use the cessation of movement of other flies as a cue of threat and its resumption as a cue of safety. Finally, we find that lobula columnar neurons, LC11, mediate the propensity for freezing flies to resume moving in response to the movement of others. By identifying visual motion cues, and the neurons involved in their processing, as the basis of a social safety cue this study brings new insights into the neuronal basis of safety in numbers.
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29
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McKee A, McHenry MJ. The Strategy of Predator Evasion in Response to a Visual Looming Stimulus in Zebrafish ( Danio rerio). Integr Org Biol 2020; 2:obaa023. [PMID: 33791564 PMCID: PMC7750966 DOI: 10.1093/iob/obaa023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A diversity of animals survive encounters with predators by escaping from a looming visual stimulus. Despite the importance of this behavior, it is generally unclear how visual cues facilitate a prey’s survival from predation. Therefore, the aim of this study was to understand how the visual angle subtended on the eye of the prey by the predator affects the distance of adult zebrafish (Danio rerio) from predators. We performed experiments to measure the threshold visual angle and mathematically modeled the kinematics of predator and prey. We analyzed the responses to the artificial stimulus with a novel approach that calculated relationships between hypothetical values for a threshold-stimulus angle and the latency between stimulus and response. These relationships were verified against the kinematic responses of zebrafish to a live fish predator (Herichthys cyanoguttatus). The predictions of our model suggest that the measured threshold visual angle facilitates escape when the predator’s approach is slower than approximately twice the prey’s escape speed. These results demonstrate the capacity and limits to how the visual angle provides a prey with the means to escape a predator.
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Affiliation(s)
- A McKee
- Department of Ecology and Evolutionary Biology, University of California, 321 Steinhaus Hall, Irvine, CA 92697, Irvine
| | - M J McHenry
- Department of Ecology and Evolutionary Biology, University of California, 321 Steinhaus Hall, Irvine, CA 92697, Irvine
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30
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McElroy EJ, Sustaita D, McBrayer LD. Applied Functional Biology: Linking Ecological Morphology to Conservation and Management. Integr Comp Biol 2020. [DOI: 10.1093/icb/icaa076] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Synopsis
Many researchers work at the interface of organisms and environment. Too often, the insights that organismal, or functional, biologists can bring to the understanding of natural history, ecology, and conservation of species are overlooked. Likewise, natural resource managers are frequently focused on the management of populations and communities, while ignoring key functional traits that might explain variation in abundance and shifts in species composition at these ecological levels. Our intention for this symposium is two-fold: (1) to bring to light current and future research in functional and ecological morphology applicable to concerns and goals of wildlife management and conservation and (2) to show how such studies can result in measurable benchmarks useful to regulatory agencies. Symposium topics reveal past, present, and future collaborations between functional morphologists/biomechanists and conservation/wildlife biologists. During the SICB 2020 Annual Meeting, symposium participants demonstrated how data gathered to address fundamental questions regarding the causes and consequences of organismal form and function can also help address issues of conservation and wildlife management. Here we review how these, and other, studies of functional morphology, biomechanics, ecological development morphology and performance can inform wildlife conservation and management, principally by identifying candidate functional traits that have clear fitness consequences and population level implications.
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Affiliation(s)
- Eric J McElroy
- Department of Biology, College of Charleston, Charleston, SC 29412, USA
| | - Diego Sustaita
- Department of Biological Sciences, California State University San Marcos, San Marcos, CA 92096, USA
| | - Lance D McBrayer
- Department of Biology, Georgia Southern University, Statesboro, GA 30460, USA
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31
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Bauer U, Poppinga S, Müller UK. Mechanical Ecology-Taking Biomechanics to the Field. Integr Comp Biol 2020; 60:820-828. [PMID: 32275745 DOI: 10.1093/icb/icaa018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Synopsis Interdisciplinary research can have strong and surprising synergistic effects, leading to rapid knowledge gains. Equally important, it can help to reintegrate fragmented fields across increasingly isolated specialist sub-disciplines. However, the lack of a common identifier for research "in between fields" can make it difficult to find relevant research outputs and network effectively. We illustrate and address this issue for the emerging interdisciplinary hotspot of "mechanical ecology," which we define here as the intersection of quantitative biomechanics and field ecology at the organism level. We show that an integrative approach crucially advances our understanding in both disciplines by (1) putting biomechanical mechanisms into a biologically meaningful ecological context and (2) addressing the largely neglected influence of mechanical factors in organismal and behavioral ecology. We call for the foundation of knowledge exchange platforms such as meeting symposia, special issues in journals, and focus groups dedicated to mechanical ecology.
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Affiliation(s)
- Ulrike Bauer
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Simon Poppinga
- Plant Biomechanics Group, Botanic Garden, University of Freiburg, Freiburg im Breisgau, Germany.,Freiburg Materials Research Center (FMF), University of Freiburg, Freiburg im Breisgau, Germany
| | - Ulrike K Müller
- Department of Biology, California State University Fresno, Fresno, CA, USA
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32
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Cinel SD, Hahn DA, Kawahara AY. Predator-induced stress responses in insects: A review. JOURNAL OF INSECT PHYSIOLOGY 2020; 122:104039. [PMID: 32113954 DOI: 10.1016/j.jinsphys.2020.104039] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 04/26/2018] [Accepted: 02/26/2020] [Indexed: 06/10/2023]
Abstract
Predators can induce extreme stress and profound physiological responses in prey. Insects are the most dominant animal group on Earth and serve as prey for many different predators. Although insects have an extraordinary diversity of anti-predator behavioral and physiological responses, predator-induced stress has not been studied extensively in insects, especially at the molecular level. Here, we review the existing literature on physiological predator-induced stress responses in insects and compare what is known about insect stress to vertebrate stress systems. We conclude that many unrelated insects share a baseline pathway of predator-induced stress responses that we refer to as the octopamine-adipokinetic hormone (OAH) axis. We also present best practices for studying predator-induced stress responses in prey insects. We encourage investigators to compare neurophysiological responses to predator-related stress at the organismal, neurohormonal, tissue, and cellular levels within and across taxonomic groups. Studying stress-response variation between ecological contexts and across taxonomic levels will enable the field to build a holistic understanding of, and distinction between, taxon- and stimulus-specific responses relative to universal stress responses.
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Affiliation(s)
- Scott D Cinel
- Department of Biology, University of Florida, Gainesville, FL 32611, USA; Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA.
| | - Daniel A Hahn
- Department of Entomology & Nematology, University of Florida, Gainesville, FL 32611, USA
| | - Akito Y Kawahara
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
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33
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Sato N, Shidara H, Ogawa H. Trade-off between motor performance and behavioural flexibility in the action selection of cricket escape behaviour. Sci Rep 2019; 9:18112. [PMID: 31792301 PMCID: PMC6889515 DOI: 10.1038/s41598-019-54555-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/13/2019] [Indexed: 11/30/2022] Open
Abstract
To survive a predator’s attack successfully, animals choose appropriate actions from multiple escape responses. The motor performance of escape response governs successful survival, which implies that the action selection in escape behaviour is based on the trade-off between competing behavioural benefits. Thus, quantitative assessment of motor performance will shed light on the biological basis of decision-making. To explore the trade-off underlying the action selection, we focused on two distinct wind-elicited escape responses of crickets, running and jumping. We first hypothesized a trade-off between speed and directional accuracy. This hypothesis was rejected because crickets could control the escape direction in jumping as precisely as in running; further, jumping had advantages with regard to escape speed. Next, we assumed behavioural flexibility, including responsiveness to additional predator’s attacks, as a benefit of running. The double stimulus experiment revealed that crickets running in the first response could respond more frequently to a second stimulus and control the movement direction more precisely compared to when they chose jumping for the first response. These data suggest that not only the motor performance but also the future adaptability of subsequent behaviours are considered as behavioural benefits, which may be used for choosing appropriate escape reactions.
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Affiliation(s)
- Nodoka Sato
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Hisashi Shidara
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Hiroto Ogawa
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
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34
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Ferreira CH, Moita MA. What can a non-eusocial insect tell us about the neural basis of group behaviour? CURRENT OPINION IN INSECT SCIENCE 2019; 36:118-124. [PMID: 31563022 DOI: 10.1016/j.cois.2019.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 08/25/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
Group behaviour has been extensively studied in canonically social swarming, shoaling and flocking vertebrates and invertebrates, providing great insight into the behavioural and ecological aspects of group living. However, the search for its neuronal basis is lagging behind. In the natural environment, Drosophila melanogaster, increasingly used as a model to study neuronal circuits and behaviour, spend their lives surrounded by several conspecifics of different stages, as well as heterospecifics. Despite their dynamic multi-organism natural environment, the neuronal basis of social behaviours has been typically studied in dyadic interactions, such as mating or aggression. This review will focus on recent studies regarding how the behaviour of fruit flies can be shaped by the nature of the surrounding group. We argue that the rich social environment of Drosophila melanogaster, its arsenal of neurogenetic tools and the ability to use large sample sizes for detailed quantitative behavioural analysis makes this species ideal for mechanistic studies of group behaviour.
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Affiliation(s)
- Clara H Ferreira
- Champalimaud Research, Champalimaud Center for the Unknown, 1400-038 Lisbon, Portugal.
| | - Marta A Moita
- Champalimaud Research, Champalimaud Center for the Unknown, 1400-038 Lisbon, Portugal.
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35
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Cloyed CS, Dell AI. Resource distribution and internal factors interact to govern movement of a freshwater snail. Proc Biol Sci 2019; 286:20191610. [PMID: 31551058 DOI: 10.1098/rspb.2019.1610] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Movement enables mobile organisms to respond to local environmental conditions and is driven by a combination of external and internal factors operating at multiple scales. Here, we explored how resource distribution interacted with the internal state of organisms to drive patterns of movement. Specifically, we tracked snail movements on experimental landscapes where resource (algal biofilm) distribution varied from 0 to 100% coverage and quantified how that movement changed over a 24 h period. Resource distribution strongly affected snail movement. Trajectories were tortuous (i.e. Brownian-like) within resource patches but straighter (i.e. Lévy) in resource-free (bare) patches. The average snail speed was slower in resource patches, where snails spent most of their time. Different patterns of movement between resource and bare patches explained movement at larger spatial scales; movement was ballistic-like Lévy in resource-free landscapes, Lévy in landscapes with intermediate resource coverage and approximated Brownian in landscapes covered in resources. Our temporal analysis revealed that movement patterns changed predictably for snails that satiated their hunger and then performed other behaviours. These changes in movement patterns through time were similar across all treatments that contained resources. Thus, external and internal factors interacted to shape the inherently flexible movement of these snails.
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Affiliation(s)
- Carl S Cloyed
- National Great Rivers Research and Education Center, East Alton, IL 62024, USA.,Department of Biology, Washington University of St Louis, St Louis, MO 63130, USA.,Dauphin Island Sea Lab, Dauphin Island, AL 36528, USA
| | - Anthony I Dell
- National Great Rivers Research and Education Center, East Alton, IL 62024, USA.,Department of Biology, Washington University of St Louis, St Louis, MO 63130, USA
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36
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A Target-Detecting Visual Neuron in the Dragonfly Locks on to Selectively Attended Targets. J Neurosci 2019; 39:8497-8509. [PMID: 31519823 DOI: 10.1523/jneurosci.1431-19.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 01/23/2023] Open
Abstract
The visual world projects a complex and rapidly changing image onto the retina of many animal species. This presents computational challenges for those animals reliant on visual processing to provide an accurate representation of the world. One such challenge is parsing a visual scene for the most salient targets, such as the selection of prey amid a swarm. The ability to selectively prioritize processing of some stimuli over others is known as 'selective attention'. We recently identified a dragonfly visual neuron called 'Centrifugal Small Target Motion Detector 1' (CSTMD1) that exhibits selective attention when presented with multiple, equally salient targets. Here we conducted in vivo, electrophysiological recordings from CSTMD1 in wild-caught male dragonflies (Hemicordulia tau), while presenting visual stimuli on an LCD monitor. To identify the target selected in any given trial, we uniquely modulated the intensity of the moving targets (frequency tagging). We found that the frequency information of the selected target is preserved in the neuronal response, while the distracter is completely ignored. We also show that the competitive system that underlies selection in this neuron can be biased by the presentation of a preceding target on the same trajectory, even when it is of lower contrast than an abrupt, novel distracter. With this improved method for identifying and biasing target selection in CSTMD1, the dragonfly provides an ideal animal model system to probe the neuronal mechanisms underlying selective attention.SIGNIFICANCE STATEMENT We present the first application of frequency tagging to intracellular neuronal recordings, demonstrating that the frequency component of a stimulus is encoded in the spiking response of an individual neuron. Using this technique as an identifier, we demonstrate that CSTMD1 'locks on' to a selected target and encodes the absolute strength of this target, even in the presence of abruptly appearing, high-contrast distracters. The underlying mechanism also permits the selection mechanism to switch between targets mid-trial, even among equivalent targets. Together, these results demonstrate greater complexity in this selective attention system than would be expected in a winner-takes-all network. These results are in contrast to typical findings in the primate and avian brain, but display intriguing resemblance to observations in human psychophysics.
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37
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Lohmann AC, Corcoran AJ, Hedrick TL. Dragonflies use underdamped pursuit to chase conspecifics. ACTA ACUST UNITED AC 2019; 222:222/11/jeb190884. [PMID: 31186342 DOI: 10.1242/jeb.190884] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 05/10/2019] [Indexed: 12/27/2022]
Abstract
Pursuit is a common behavior exhibited by animals chasing prey, competitors and potential mates. Because of their speed and maneuverability, dragonflies are frequently studied as a model system for biological pursuit. Most quantitative studies have focused on prey pursuits in captive environments. To determine whether a different pursuit strategy is used when chasing conspecifics of nearly equal speed and agility, we recorded 3D flight trajectories from nine territorial chases between male Erythemis simplicicollis dragonflies in natural field conditions. During chases, dragonflies used an interception strategy with an unusually high-magnitude gain (k=-10.03 s-1 horizontal; -8.86 s-1 vertical) and short time delay (τ=50 ms). The product kτ determines how aggressively a pursuer corrects course to achieve interception. Previous studies of prey pursuit have found kτ values close to -1/e (-0.37), the time-optimal value for achieving pursuit without overshooting. However, we found that dragonflies chasing conspecifics use more negative kτ (-0.50 horizontal; -0.44 vertical), resulting in pursuits with a high degree of overshooting (i.e. moving past the target and alternating position from side to side). We confirmed via simulation that the observed gain and delay produce overshooting. We propose that overshooting is an adaptive feature of conspecific chases that can be achieved with only slight modification of the strategy used for intercepting prey. Overshooting might help avoid potentially damaging collisions while exhibiting the pursuing animal's flight performance and competitive ability. Repeated close approaches might also evoke evasive responses from the other dragonfly, effectively herding the competitor out of the territory.
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Affiliation(s)
- Amanda C Lohmann
- Department of Biology, University of North Carolina, Chapel Hill, NC 27514, USA .,Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 28516, USA
| | - Aaron J Corcoran
- Department of Biology, University of North Carolina, Chapel Hill, NC 27514, USA
| | - Tyson L Hedrick
- Department of Biology, University of North Carolina, Chapel Hill, NC 27514, USA
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38
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Feilich KL, López-Fernández H. When Does Form Reflect Function? Acknowledging and Supporting Ecomorphological Assumptions. Integr Comp Biol 2019; 59:358-370. [DOI: 10.1093/icb/icz070] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Ecomorphology is the study of relationships between organismal morphology and ecology. As such, it is the only way to determine if morphometric data can be used as an informative proxy for ecological variables of interest. To achieve this goal, ecomorphology often depends on, or directly tests, assumptions about the nature of the relationships among morphology, performance, and ecology. We discuss three approaches to the study of ecomorphology: morphometry-driven, function-driven, and ecology-driven and study design choices inherent to each approach. We also identify 10 assumptions that underlie ecomorphological research: 4 of these are central to all ecomorphological studies and the remaining 6 are variably applicable to some of the specific approaches described above. We discuss how these assumptions may impact ecomorphological studies and affect the interpretation of their findings. We also point out some limitations of ecomorphological studies, and highlight some ways by which we can strengthen, validate, or eliminate systematic assumptions.
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Affiliation(s)
- Kara L Feilich
- Museum of Paleontology, University of Michigan, 1105 North University Ave, Ann Arbor, MI 48109, USA
| | - Hernán López-Fernández
- Department of Ecology and Evolutionary Biology and Museum of Zoology, University of Michigan, 1105 North University Ave, Ann Arbor, MI 48109, USA
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39
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Whitford MD, Freymiller GA, Higham TE, Clark RW. Determinants of predation success: How to survive an attack from a rattlesnake. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13318] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Malachi D. Whitford
- Department of Biology San Diego State University San Diego California
- Ecology Graduate Group University of California Davis California
| | - Grace A. Freymiller
- Department of Biology San Diego State University San Diego California
- Department of Evolution, Ecology, and Organismal Biology University of California Riverside California
| | - Timothy E. Higham
- Department of Evolution, Ecology, and Organismal Biology University of California Riverside California
| | - Rulon W. Clark
- Department of Biology San Diego State University San Diego California
- Chiricahua Desert Museum Rodeo New Mexico
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40
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Freymiller GA, Whitford MD, Higham TE, Clark RW. Escape dynamics of free-ranging desert kangaroo rats (Rodentia: Heteromyidae) evading rattlesnake strikes. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Grace A Freymiller
- Department of Biology, San Diego State University, San Diego, CA, USA
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, USA
| | - Malachi D Whitford
- Department of Biology, San Diego State University, San Diego, CA, USA
- Graduate Group in Ecology, University of California, Davis, CA, USA
| | - Timothy E Higham
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, USA
| | - Rulon W Clark
- Department of Biology, San Diego State University, San Diego, CA, USA
- Chiricahua Desert Museum, Rodeo, NM, USA
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41
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Le Roy C, Debat V, Llaurens V. Adaptive evolution of butterfly wing shape: from morphology to behaviour. Biol Rev Camb Philos Soc 2019; 94:1261-1281. [PMID: 30793489 DOI: 10.1111/brv.12500] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/21/2019] [Accepted: 01/23/2019] [Indexed: 01/07/2023]
Abstract
Butterflies display extreme variation in wing shape associated with tremendous ecological diversity. Disentangling the role of neutral versus adaptive processes in wing shape diversification remains a challenge for evolutionary biologists. Ascertaining how natural selection influences wing shape evolution requires both functional studies linking morphology to flight performance, and ecological investigations linking performance in the wild with fitness. However, direct links between morphological variation and fitness have rarely been established. The functional morphology of butterfly flight has been investigated but selective forces acting on flight behaviour and associated wing shape have received less attention. Here, we attempt to estimate the ecological relevance of morpho-functional links established through biomechanical studies in order to understand the evolution of butterfly wing morphology. We survey the evidence for natural and sexual selection driving wing shape evolution in butterflies, and discuss how our functional knowledge may allow identification of the selective forces involved, at both the macro- and micro-evolutionary scales. Our review shows that although correlations between wing shape variation and ecological factors have been established at the macro-evolutionary level, the underlying selective pressures often remain unclear. We identify the need to investigate flight behaviour in relevant ecological contexts to detect variation in fitness-related traits. Identifying the selective regime then should guide experimental studies towards the relevant estimates of flight performance. Habitat, predators and sex-specific behaviours are likely to be major selective forces acting on wing shape evolution in butterflies. Some striking cases of morphological divergence driven by contrasting ecology involve both wing and body morphology, indicating that their interactions should be included in future studies investigating co-evolution between morphology and flight behaviour.
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Affiliation(s)
- Camille Le Roy
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier CP50, 75005, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, 12 rue de l'École de Médecine, 75006, Paris, France
| | - Vincent Debat
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier CP50, 75005, Paris, France
| | - Violaine Llaurens
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier CP50, 75005, Paris, France
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42
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Warren TL, Giraldo YM, Dickinson MH. Celestial navigation in Drosophila. ACTA ACUST UNITED AC 2019; 222:222/Suppl_1/jeb186148. [PMID: 30728228 DOI: 10.1242/jeb.186148] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Many casual observers typecast Drosophila melanogaster as a stationary pest that lurks around fruit and wine. However, the omnipresent fruit fly, which thrives even in desert habitats, likely established and maintained its cosmopolitan status via migration over large spatial scales. To perform long-distance dispersal, flies must actively maintain a straight compass heading through the use of external orientation cues, such as those derived from the sky. In this Review, we address how D. melanogaster accomplishes long-distance navigation using celestial cues. We focus on behavioral and physiological studies indicating that fruit flies can navigate both to a pattern of linearly polarized light and to the position of the sun - the same cues utilized by more heralded insect navigators such as monarch butterflies and desert ants. In both cases, fruit flies perform menotaxis, selecting seemingly arbitrary headings that they then maintain over time. We discuss how the fly's nervous system detects and processes this sensory information to direct the steering maneuvers that underlie navigation. In particular, we highlight recent findings that compass neurons in the central complex, a set of midline neuropils, are essential for navigation. Taken together, these results suggest that fruit flies share an ancient, latent capacity for celestial navigation with other insects. Furthermore, they illustrate the potential of D. melanogaster to help us to elucidate both the cellular basis of navigation and mechanisms of directed dispersal on a landscape scale.
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Affiliation(s)
- Timothy L Warren
- Institute of Neuroscience, Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA
| | - Ysabel M Giraldo
- Division of Biology and Biological Engineering, Caltech, Pasadena, CA 91125, USA
| | - Michael H Dickinson
- Division of Biology and Biological Engineering, Caltech, Pasadena, CA 91125, USA
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Ortega-Jiménez VM, Combes SA. Living in a trash can: turbulent convective flows impair Drosophila flight performance. J R Soc Interface 2018; 15:rsif.2018.0636. [PMID: 30355810 DOI: 10.1098/rsif.2018.0636] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 10/01/2018] [Indexed: 11/12/2022] Open
Abstract
Turbulent flows associated with thermal convection are common in areas where the ground is heated by solar radiation, fermentation or other processes. However, it is unknown how these flow instabilities affect the locomotion of small insects, like fruit flies, that inhabit deserts and urban landscapes where surface temperatures can reach extreme values. We quantified flight performance of fruit flies (Drosophila melanogaster) traversing a chamber through still air and turbulent Rayleigh-Bénard convection cells produced by a vertical temperature gradient. A total of 34% of individuals were unable to reach the end of the chamber in convection, although peak flow speeds were modest relative to typical outdoor airflow. Individuals that were successful in convection were faster fliers and had larger wing areas than those that failed. All flies displayed higher pitch angles and lower mean flight speeds in convection. Successful individuals took longer to cross the chamber in convection, due to lower flight speeds and greater path sinuosity. All individuals displayed higher flapping frequencies in convection, and successful individuals also reduced stroke amplitude. Our results suggest that thermal convection poses a significant challenge for small fliers, resulting in increased travel times and energetic costs, or in some cases precluding insects from traversing these environments entirely.
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Affiliation(s)
| | - Stacey A Combes
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA, USA
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Hefler C, Qiu H, Shyy W. Aerodynamic characteristics along the wing span of a dragonfly Pantala flavescens. ACTA ACUST UNITED AC 2018; 221:jeb.171199. [PMID: 30108128 DOI: 10.1242/jeb.171199] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 08/04/2018] [Indexed: 12/17/2022]
Abstract
We investigated the characteristics of interwing aerodynamic interactions across the span of the high aspect ratio, flexible wings of dragonflies under tethered and free-flying conditions. This revealed that the effects of the interactions on the hindwings vary across four spanwise regions. (i) Close to the wing root, a trailing-edge vortex (TEV) is formed by each stroke, while the formation of a leading-edge vortex (LEV) is limited by the short translational distance of the hindwing and suppressed by the forewing-induced flow. (ii) In the region away from the wing root but not quite up to midspan, the formation of the hindwing LEV is influenced by that of the forewing LEV. This vortex synergy can increase the circulation of the hindwing LEV in the corresponding cross-section by 22% versus that of the hindwing in isolation. (iii) In the region about half-way between the wing root and wing tip there is a transition dominated by downwash from the forewing resulting in flow attached to the hindwing. (iv) A LEV is developed in the remaining, outer region of the wing at the end of a stroke when the hindwing captures the vortex shed by the forewing. The interaction effects depend not only on the wing phasing but also on the flapping offset and flight direction. The aerodynamics of the hindwings vary substantially from the wing root to the wing tip. For a given phasing, this spanwise variation in the aerodynamics can be exploited in the design of artificial wings to achieve greater agility and higher efficiency.
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Affiliation(s)
- Csaba Hefler
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Huihe Qiu
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | - Wei Shyy
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
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45
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Karásek M, Muijres FT, De Wagter C, Remes BDW, de Croon GCHE. A tailless aerial robotic flapper reveals that flies use torque coupling in rapid banked turns. Science 2018; 361:1089-1094. [DOI: 10.1126/science.aat0350] [Citation(s) in RCA: 176] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/04/2018] [Accepted: 07/20/2018] [Indexed: 02/06/2023]
Abstract
Insects are among the most agile natural flyers. Hypotheses on their flight control cannot always be validated by experiments with animals or tethered robots. To this end, we developed a programmable and agile autonomous free-flying robot controlled through bio-inspired motion changes of its flapping wings. Despite being 55 times the size of a fruit fly, the robot can accurately mimic the rapid escape maneuvers of flies, including a correcting yaw rotation toward the escape heading. Because the robot’s yaw control was turned off, we showed that these yaw rotations result from passive, translation-induced aerodynamic coupling between the yaw torque and the roll and pitch torques produced throughout the maneuver. The robot enables new methods for studying animal flight, and its flight characteristics allow for real-world flight missions.
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Affiliation(s)
- Matěj Karásek
- Micro Air Vehicle Laboratory, Control and Simulation, Delft University of Technology, Delft, Netherlands
| | - Florian T. Muijres
- Experimental Zoology Group, Wageningen University and Research, Wageningen, Netherlands
| | - Christophe De Wagter
- Micro Air Vehicle Laboratory, Control and Simulation, Delft University of Technology, Delft, Netherlands
| | - Bart D. W. Remes
- Micro Air Vehicle Laboratory, Control and Simulation, Delft University of Technology, Delft, Netherlands
| | - Guido C. H. E. de Croon
- Micro Air Vehicle Laboratory, Control and Simulation, Delft University of Technology, Delft, Netherlands
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46
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Richardson G, Dickinson P, Burman OHP, Pike TW. Unpredictable movement as an anti-predator strategy. Proc Biol Sci 2018; 285:20181112. [PMID: 30135159 PMCID: PMC6125907 DOI: 10.1098/rspb.2018.1112] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 07/20/2018] [Indexed: 11/12/2022] Open
Abstract
Prey animals have evolved a wide variety of behaviours to combat the threat of predation, and these have been generally well studied. However, one of the most common and taxonomically widespread antipredator behaviours of all has, remarkably, received almost no experimental attention: so-called 'protean' behaviour. This is behaviour that is sufficiently unpredictable to prevent a predator anticipating in detail the future position or actions of its prey. In this study, we used human 'predators' participating in 3D virtual reality simulations to test how protean (i.e. unpredictable) variation in prey movement affects participants' ability to visually target them as they move (a key determinant of successful predation). We found that targeting accuracy was significantly predicted by prey movement path complexity, although, surprisingly, there was little evidence that high levels of unpredictability in the underlying movement rules equated directly to decreased predator performance. Instead, the specific movement rules differed in how they impacted on targeting accuracy, with the efficacy of protean variation in one element depending on the values of the remaining elements. These findings provide important insights into the understudied phenomenon of protean antipredator behaviour, which are directly applicable to predator-prey dynamics within a broad range of taxa.
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Affiliation(s)
- Graham Richardson
- School of Life Sciences, University of Lincoln, Lincoln LN6 7DL, UK
- School of Computer Science, University of Lincoln, Lincoln LN6 7TS, UK
| | - Patrick Dickinson
- School of Computer Science, University of Lincoln, Lincoln LN6 7TS, UK
| | | | - Thomas W Pike
- School of Life Sciences, University of Lincoln, Lincoln LN6 7DL, UK
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47
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Rubin JJ, Hamilton CA, McClure CJW, Chadwell BA, Kawahara AY, Barber JR. The evolution of anti-bat sensory illusions in moths. SCIENCE ADVANCES 2018; 4:eaar7428. [PMID: 29978042 PMCID: PMC6031379 DOI: 10.1126/sciadv.aar7428] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
Prey transmit sensory illusions to redirect predatory strikes, creating a discrepancy between what a predator perceives and reality. We use the acoustic arms race between bats and moths to investigate the evolution and function of a sensory illusion. The spinning hindwing tails of silk moths (Saturniidae) divert bat attack by reflecting sonar to create a misleading echoic target. We characterized geometric morphometrics of moth hindwings across silk moths, mapped these traits onto a new, robust phylogeny, and found that elaborated hindwing structures have converged on four adaptive shape peaks. To test the mechanism underlying these anti-bat traits, we pit bats against three species of silk moths with experimentally altered hindwings that created a representative gradient of ancestral and extant hindwing shapes. High-speed videography of battles reveals that moths with longer hindwings and tails more successfully divert bat attack. We postulate that sensory illusions are widespread and are underappreciated drivers of diversity across systems.
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Affiliation(s)
| | - Chris A. Hamilton
- The McGuire Center for Lepidoptera and Biodiversity, University of Florida, Gainesville, FL 32611, USA
| | - Chris J. W. McClure
- Boise State University, Boise, ID 83725, USA
- The Peregrine Fund, Boise, ID 83709, USA
| | | | - Akito Y. Kawahara
- The McGuire Center for Lepidoptera and Biodiversity, University of Florida, Gainesville, FL 32611, USA
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Brydegaard M, Jansson S, Schulz M, Runemark A. Can the narrow red bands of dragonflies be used to perceive wing interference patterns? Ecol Evol 2018; 8:5369-5384. [PMID: 29938059 PMCID: PMC6010746 DOI: 10.1002/ece3.4054] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/28/2018] [Accepted: 03/05/2018] [Indexed: 01/12/2023] Open
Abstract
Despite numerous studies of selection on position and number of spectral vision bands, explanations to the function of narrow spectral bands are lacking. We investigate dragonflies (Odonata), which have the narrowest spectral bands reported, in order to investigate what features these narrow spectral bands may be used to perceive. We address whether it is likely that narrow red bands can be used to identify conspecifics by the optical signature from wing interference patterns (WIPs). We investigate the optical signatures of Odonata wings using hyperspectral imaging, laser profiling, ellipsometry, polarimetric modulation spectroscopy, and laser radar experiments. Based on results, we estimate the prospects for Odonata perception of WIPs to identify conspecifics in the spectral, spatial, intensity, polarization, angular, and temporal domains. We find six lines of evidence consistent with an ability to perceive WIPs. First, the wing membrane thickness of the studied Odonata is 2.3 μm, coinciding with the maximal thickness perceivable by the reported bandwidth. Second, flat wings imply that WIPs persist from whole wings, which can be seen at a distance. Third, WIPs constitute a major brightness in the visual environment only second after the solar disk. Fourth, WIPs exhibit high degree of polarization and polarization vision coincides with frontal narrow red bands in Odonata. Fifth, the angular light incidence on the Odonata composite eye provides all prerequisites for direct assessment of the refractive index which is associated with age. Sixth, WIPs from conspecifics in flight make a significant contribution even to the fundamental wingbeat frequency within the flicker fusion bandwidth of Odonata vision. We conclude that it is likely that WIPs can be perceived by the narrow red bands found in some Odonata species and propose future behavioral and electrophysiological tests of this hypothesis.
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Affiliation(s)
- Mikkel Brydegaard
- Department of PhysicsLund UniversityLundSweden
- Norsk Elektro Optikk ASSkedsmokorsetNorway
- Department of BiologyLund UniversityLundSweden
| | | | | | - Anna Runemark
- Department of BiologyLund UniversityLundSweden
- Department of BiosciencesUniversity of OsloOsloNorway
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49
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Role of side-slip flight in target pursuit: blue-tailed damselflies (Ischnura elegans) avoid body rotation while approaching a moving perch. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2018; 204:561-577. [PMID: 29666930 DOI: 10.1007/s00359-018-1261-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/08/2018] [Accepted: 04/09/2018] [Indexed: 01/19/2023]
Abstract
Visually guided flight control requires processing changes in the visual panorama (optic-flow) resulting from self-movement relative to stationary objects, as well as from moving objects passing through the field of view. We studied the ability of the blue-tailed damselfly, Ischnura elegans, to successfully land on a perch moving unpredictably. We tracked the insects landing on a vertical pole moved linearly 6 cm back and forth with sinusoidal changes in velocity. When the moving perch changed direction at frequencies higher than 1 Hz, the damselflies engaged in manoeuvres that typically involved sideways flight, with minimal changes in body orientation relative to the stationary environment. We show that these flight manoeuvres attempted to fix the target in the centre of the field of view when flying in any direction while keeping body rotation changes about the yaw axis to the minimum. We propose that this pursuit strategy allows the insect to obtain reliable information on self and target motion relative to the stationary environment from the translational optic-flow, while minimizing interference from the rotational optic-flow. The ability of damselflies to fly in any direction, irrespective of body orientation, underlines the superb flight control of these aerial predators.
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50
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Wainwright PC. How hummingbirds stay nimble on the wing. Science 2018; 359:636-637. [DOI: 10.1126/science.aar7615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Videos of more than 200 hummingbirds reveal the evolutionary basis of their maneuvering skills
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Affiliation(s)
- Peter C. Wainwright
- Department of Evolution and Ecology, University of California, Davis, Davis, CA 95616, USA
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