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Taub M, Goldshtein A, Boonman A, Eitan O, Hurme E, Greif S, Yovel Y. What determines the information update rate in echolocating bats. Commun Biol 2023; 6:1187. [PMID: 37989853 PMCID: PMC10663583 DOI: 10.1038/s42003-023-05563-x] [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: 08/03/2023] [Accepted: 11/09/2023] [Indexed: 11/23/2023] Open
Abstract
The rate of sensory update is one of the most important parameters of any sensory system. The acquisition rate of most sensory systems is fixed and has been optimized by evolution to the needs of the animal. Echolocating bats have the ability to adjust their sensory update rate which is determined by the intervals between emissions - the inter-pulse intervals (IPI). The IPI is routinely adjusted, but the exact factors driving its regulation are unknown. We use on-board audio recordings to determine how four species of echolocating bats with different foraging strategies regulate their sensory update rate during commute flights. We reveal strong correlations between the IPI and various echolocation and movement parameters. Specifically, the update rate increases when the signals' peak-energy frequency and intensity increases while the update rate decreases when flight speed and altitude increases. We suggest that bats control their information update rate according to the behavioral mode they are engaged in, while always maintaining sensory continuity. Specifically, we suggest that bats apply two modes of attention during commute flights. Our data moreover suggests that bats emit echolocation signals at accurate intervals without the need for external feedback.
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Affiliation(s)
- Mor Taub
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Aya Goldshtein
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
- Department of Collective Behaviour, Max Planck Institute of Animal Behaviour, Konstanz, 78464, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Arjan Boonman
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Ofri Eitan
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Edward Hurme
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - Stefan Greif
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Yossi Yovel
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel.
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel.
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2
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Seifert M, Roberts PA, Kafetzis G, Osorio D, Baden T. Birds multiplex spectral and temporal visual information via retinal On- and Off-channels. Nat Commun 2023; 14:5308. [PMID: 37652912 PMCID: PMC10471707 DOI: 10.1038/s41467-023-41032-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 08/18/2023] [Indexed: 09/02/2023] Open
Abstract
In vertebrate vision, early retinal circuits divide incoming visual information into functionally opposite elementary signals: On and Off, transient and sustained, chromatic and achromatic. Together these signals can yield an efficient representation of the scene for transmission to the brain via the optic nerve. However, this long-standing interpretation of retinal function is based on mammals, and it is unclear whether this functional arrangement is common to all vertebrates. Here we show that male poultry chicks use a fundamentally different strategy to communicate information from the eye to the brain. Rather than using functionally opposite pairs of retinal output channels, chicks encode the polarity, timing, and spectral composition of visual stimuli in a highly correlated manner: fast achromatic information is encoded by Off-circuits, and slow chromatic information overwhelmingly by On-circuits. Moreover, most retinal output channels combine On- and Off-circuits to simultaneously encode, or multiplex, both achromatic and chromatic information. Our results from birds conform to evidence from fish, amphibians, and reptiles which retain the full ancestral complement of four spectral types of cone photoreceptors.
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Affiliation(s)
- Marvin Seifert
- School of Life Sciences, University of Sussex, Brighton, UK.
| | - Paul A Roberts
- School of Life Sciences, University of Sussex, Brighton, UK
| | | | - Daniel Osorio
- School of Life Sciences, University of Sussex, Brighton, UK.
| | - Tom Baden
- School of Life Sciences, University of Sussex, Brighton, UK.
- Institute of Ophthalmic Research, University of Tübingen, Tübingen, Germany.
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3
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Rubin JJ, Kawahara AY. A framework for understanding post-detection deception in predator-prey interactions. PeerJ 2023; 11:e15389. [PMID: 37377786 PMCID: PMC10292197 DOI: 10.7717/peerj.15389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 04/19/2023] [Indexed: 06/29/2023] Open
Abstract
Predators and prey exist in persistent conflict that often hinges on deception-the transmission of misleading or manipulative signals-as a means for survival. Deceptive traits are widespread across taxa and sensory systems, representing an evolutionarily successful and common strategy. Moreover, the highly conserved nature of the major sensory systems often extends these traits past single species predator-prey interactions toward a broader set of perceivers. As such, deceptive traits can provide a unique window into the capabilities, constraints and commonalities across divergent and phylogenetically-related perceivers. Researchers have studied deceptive traits for centuries, but a unified framework for categorizing different types of post-detection deception in predator-prey conflict still holds potential to inform future research. We suggest that deceptive traits can be distinguished by their effect on object formation processes. Perceptual objects are composed of physical attributes (what) and spatial (where) information. Deceptive traits that operate after object formation can therefore influence the perception and processing of either or both of these axes. We build upon previous work using a perceiver perspective approach to delineate deceptive traits by whether they closely match the sensory information of another object or create a discrepancy between perception and reality by exploiting the sensory shortcuts and perceptual biases of their perceiver. We then further divide this second category, sensory illusions, into traits that distort object characteristics along either the what or where axes, and those that create the perception of whole novel objects, integrating the what/where axes. Using predator-prey examples, we detail each step in this framework and propose future avenues for research. We suggest that this framework will help organize the many forms of deceptive traits and help generate predictions about selective forces that have driven animal form and behavior across evolutionary time.
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Affiliation(s)
- Juliette J. Rubin
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Akito Y. Kawahara
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, USA
- Department of Biology, University of Florida, Gainesville, FL, USA
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4
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Martin GR, Banks AN. Marine birds: vision-based wind turbine collision mitigation. Glob Ecol Conserv 2023. [DOI: 10.1016/j.gecco.2023.e02386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Visual Responses to Moving and Flashed Stimuli of Neurons in Domestic Pigeon (Columba livia domestica) Optic Tectum. Animals (Basel) 2022; 12:ani12141798. [PMID: 35883345 PMCID: PMC9312236 DOI: 10.3390/ani12141798] [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: 03/20/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 12/03/2022] Open
Abstract
Simple Summary Avian can quickly and accurately detect surrounding objects (especially, moving ones). However, it was unknown how different neurons in the optic tectum (OT) in domestic pigeons (Columba livia domestica) processed moving objects compared to static ones. The electrophysiological results showed that the latency of response to moving stimuli was shorter than that to flashed ones, while the firing rates of response to moving stimulus were higher than that to flashed ones. Furthermore, the modeling study demonstrated that the faster and stronger response to a moving stimulus compared to a flashed stimulus may result from the accumulation process across space and time by tectal neurons. This study also sheds new light on the understanding of motion processing by birds. Abstract Birds can rapidly and accurately detect moving objects for better survival in complex environments. This visual ability may be attributed to the response properties of neurons in the optic tectum. However, it is unknown how neurons in the optic tectum respond differently to moving objects compared to static ones. To address this question, neuronal activities were recorded from domestic pigeon (Columba livia domestica) optic tectum, responsible for orienting to moving objects, and the responses to moving and flashed stimuli were compared. An encoding model based on the Generalized Linear Model (GLM) framework was established to explain the difference in neuronal responses. The experimental results showed that the first spike latency to moving stimuli was smaller than that to flashed ones and firing rate was higher. The model further implied the faster and stronger response to a moving target result from spatiotemporal integration process, corresponding to the spatially sequential activation of tectal neurons and the accumulation of information in time. This study provides direct electrophysiological evidence about the different tectal neuron responses to moving objects and flashed ones. The findings of this investigation increase our understanding of the motion detection mechanism of tectal neurons.
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Chaib S, Mussoi JG, Lind O, Kelber A. Visual acuity of budgerigars for moving targets. Biol Open 2021; 10:272046. [PMID: 34382651 PMCID: PMC8473842 DOI: 10.1242/bio.058796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/29/2021] [Indexed: 11/20/2022] Open
Abstract
For a bird, it is often vital to visually detect food items, predators, or individuals from the same flock, i.e. moving stimuli of various shapes. Yet, behavioural tests of visual spatial acuity traditionally use stationary gratings as stimuli. We have behaviourally tested the ability of budgerigars (Melopsittacus undulatus) to detect a black circular target, moving semi-randomly at 1.69 degrees s−1 against a brighter background. We found a detection threshold of 0.107±0.007 degrees of the visual field for a target size corresponding to a resolution of a grating with a spatial frequency of 4.68 cycles degree−1. This detection threshold is lower than the resolution limit for gratings but similar to the threshold for stationary single objects of the same shape. We conclude that the target acuity of budgerigars for moving single targets, just as for stationary single targets, is lower than their acuity for gratings. Summary: Movement does not improve detection: The detection threshold of budgerigars (Melopsittacus undulatus) for moving dark circular targets is similar to the detection threshold for stationary but otherwise similar targets.
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Affiliation(s)
- Sandra Chaib
- Lund Vision Group, Department of Biology, Lund University, 223 62 Lund, Sweden
| | | | - Olle Lind
- Lund Vision Group, Department of Biology, Lund University, 223 62 Lund, Sweden
| | - Almut Kelber
- Lund Vision Group, Department of Biology, Lund University, 223 62 Lund, Sweden
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Abstract
Time is largely a hidden variable in vision. It is the condition for seeing interesting things such as spatial forms and patterns, colours and movements in the external world, and yet is not meant to be noticed in itself. Temporal aspects of visual processing have received comparatively little attention in research. Temporal properties have been made explicit mainly in measurements of resolution and integration in simple tasks such as detection of spatially homogeneous flicker or light pulses of varying duration. Only through a mechanistic understanding of their basis in retinal photoreceptors and circuits can such measures guide modelling of natural vision in different species and illuminate functional and evolutionary trade-offs. Temporal vision research would benefit from bridging traditions that speak different languages. Towards that goal, I here review studies from the fields of human psychophysics, retinal physiology and neuroethology, with a focus on fundamental constraints set by early vision. Summary: Simple measures of temporal vision such as the critical flicker frequency can be useful for modelling natural vision only if their relationship to photoreceptor responses and retinal processing is understood.
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Affiliation(s)
- Kristian Donner
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland
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Vrettos M, Reynolds C, Amar A. Malar stripe size and prominence in peregrine falcons vary positively with solar radiation: support for the solar glare hypothesis. Biol Lett 2021; 17:20210116. [PMID: 34062086 DOI: 10.1098/rsbl.2021.0116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many falcons (Falco spp.) exhibit a distinct dark plumage patch below the eye, termed the malar stripe. This stripe is hypothesized to reduce the amount of solar glare reflected into the eyes while foraging, thereby increasing hunting efficiency in bright conditions. Here, we use a novel, global-scale correlative approach to test this 'solar glare hypothesis' in peregrine falcons (Falco peregrinus), the most widespread falcon species, using web-sourced photographs from across the species' global range. We found that the size and prominence of the malar stripe were positively associated with average annual solar radiation, but not with other environmental variables, such as temperature and rainfall. Our results provide the first published evidence for the hypothesis that this plumage feature functions to reduce the amount of solar glare reflected into the falcon's eyes, thereby improving the ability to pinpoint and target agile prey in bright conditions.
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Affiliation(s)
- Michelle Vrettos
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, Department of Biological Sciences, University of Cape Town, South Africa
| | - Chevonne Reynolds
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, Department of Biological Sciences, University of Cape Town, South Africa.,School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Arjun Amar
- FitzPatrick Institute of African Ornithology, DSI-NRF Centre of Excellence, Department of Biological Sciences, University of Cape Town, South Africa
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Abstract
Ecological diversity among diurnal birds of prey, or raptors, is highlighted regarding their sensory abilities. While raptors are believed to forage primarily using sight, the sensory demands of scavengers and predators differ, as reflected in their visual systems. Here, I have reviewed the visual specialisations of predatory and scavenging diurnal raptors, focusing on (1) the anatomy of the eye and (2) the use of vision in foraging. Predators have larger eyes than scavengers relative to their body mass, potentially highlighting the higher importance of vision in these species. Scavengers possess one centrally positioned fovea that allows for the detection of carrion at a distance. In addition to the central fovea, predators have a second, temporally positioned fovea that views the frontal visual field, possibly for prey capture. Spatial resolution does not differ between predators and scavengers. In contrast, the organisation of the visual fields reflects important divergences, with enhanced binocularity in predators opposed to an enlarged field of view in scavengers. Predators also have a larger blind spot above the head. The diversity of visual system specializations according to the foraging ecology displayed by these birds suggests a complex interplay between visual anatomy and ecology, often unrelatedly of phylogeny.
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Widespread Evolution of Molecular Resistance to Snake Venom α-Neurotoxins in Vertebrates. Toxins (Basel) 2020; 12:toxins12100638. [PMID: 33023159 PMCID: PMC7601176 DOI: 10.3390/toxins12100638] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/19/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023] Open
Abstract
Venomous snakes are important subjects of study in evolution, ecology, and biomedicine. Many venomous snakes have alpha-neurotoxins (α-neurotoxins) in their venom. These toxins bind the alpha-1 nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction, causing paralysis and asphyxia. Several venomous snakes and their predators have evolved resistance to α-neurotoxins. The resistance is conferred by steric hindrance from N-glycosylated asparagines at amino acids 187 or 189, by an arginine at position 187 that has been hypothesized to either electrostatically repulse positively charged neurotoxins or sterically interfere with α-neurotoxin binding, or proline replacements at positions 194 or 197 of the nAChR ligand-binding domain to inhibit α-neurotoxin binding through structural changes in the receptor. Here, we analyzed this domain in 148 vertebrate species, and assessed its amino acid sequences for resistance-associated mutations. Of these sequences, 89 were sequenced de novo. We find widespread convergent evolution of the N-glycosylation form of resistance in several taxa including venomous snakes and their lizard prey, but not in the snake-eating birds studied. We also document new lineages with the arginine form of inhibition. Using an in vivo assay in four species, we provide further evidence that N-glycosylation mutations reduce the toxicity of cobra venom. The nAChR is of crucial importance for normal neuromuscular function and is highly conserved throughout the vertebrates as a result. Our research shows that the evolution of α-neurotoxins in snakes may well have prompted arms races and mutations to this ancient receptor across a wide range of sympatric vertebrates. These findings underscore the inter-connectedness of the biosphere and the ripple effects that one adaption can have across global ecosystems.
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11
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Visual adaptations of diurnal and nocturnal raptors. Semin Cell Dev Biol 2020; 106:116-126. [DOI: 10.1016/j.semcdb.2020.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/06/2020] [Accepted: 05/06/2020] [Indexed: 02/06/2023]
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12
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Kingston ACN, Chappell DR, Speiser DI. A snapping shrimp has the fastest vision of any aquatic animal. Biol Lett 2020; 16:20200298. [PMID: 32574534 DOI: 10.1098/rsbl.2020.0298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Animals use their sensory systems to sample information from their environments. The physiological properties of sensory systems differ, leading animals to perceive their environments in different ways. For example, eyes have different temporal sampling rates, with faster-sampling eyes able to resolve faster-moving scenes. Eyes can also have different dynamic ranges. For every eye, there is a light level below which vision is unreliable because of an insufficient signal-to-noise ratio and a light level above which the photoreceptors are saturated. Here, we report that the eyes of the snapping shrimp Alpheus heterochaelis have a temporal sampling rate of at least 160 Hz, making them the fastest-sampling eyes ever described in an aquatic animal. Fast-sampling eyes help flying animals detect objects moving across their retinas at high angular velocities. A. heterochaelis are fast-moving animals that live in turbid, structurally complex oyster reefs and their fast-sampling eyes, like those of flying animals, may help them detect objects moving rapidly across their retinas. We also report that the eyes of A. heterochaelis have a broad dynamic range that spans conditions from late twilight (approx. 1 lux) to direct sunlight (approx. 100 000 lux), a finding consistent with the circatidal activity patterns of this shallow-dwelling species.
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Affiliation(s)
- Alexandra C N Kingston
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Daniel R Chappell
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Daniel I Speiser
- Department of Biological Sciences, University of South Carolina, Columbia, SC 29208, USA
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Affiliation(s)
- Tom Baden
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, BN1 9QG, UK; Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076, Germany.
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Knight K. Falcons’ vision up to speed for fast lifestyle. J Exp Biol 2020. [DOI: 10.1242/jeb.219493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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