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Zhang F, Yang M, Xu X, Liu X, Liu H, Jiang L, Wang S. Unperceivable motion mimicking hygroscopic geometric reshaping of pine cones. NATURE MATERIALS 2022; 21:1357-1365. [PMID: 36357689 DOI: 10.1038/s41563-022-01391-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 09/28/2022] [Indexed: 06/16/2023]
Abstract
The hygroscopic deformation of pine cones, featured by opening and closing their scales depending on the environmental humidity, is a well-known stimuli-responsive model system for artificial actuators. However, it has not been noted that the deformation of pine cones is an ultra-slow process. Here, we reveal that vascular bundles with unique parallelly arranged spring/square microtubular heterostructures dominate the hygroscopic movement, characterized as ultra-slow motion with the outer sclereids. The spring microtubes give a much larger hygroscopic deformation than that of the square microtubes along the longitudinal axis direction, which bends the vascular bundles and consequently drives the scales to move. The outer sclereids with good water retention enable the vascular-bundle-triggered deformation to proceed ultra-slowly. Drawing inspiration, we developed soft actuators enabling controllable yet unperceivable motion. The motion velocity is almost two orders of magnitude lower than that of the same-class actuators reported, which made the as-developed soft actuators applicable in camouflage and reconnaissance.
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Affiliation(s)
- Feilong Zhang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China
| | - Man Yang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China
| | - Xuetao Xu
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, P. R. China
| | - Xi Liu
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, P. R. China
| | - Huan Liu
- Research Institute for Frontier Science, Beihang University, Beijing, P. R. China.
| | - Lei Jiang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, P. R. China
- Research Institute for Frontier Science, Beihang University, Beijing, P. R. China
| | - Shutao Wang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, P. R. China.
- School of Future Technology, University of Chinese Academy of Sciences, Beijing, P. R. China.
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Shafie NJ, Anuar H, David G, Ahmad A, Abdullah MT. Bird species composition, density and feeding guilds in contrasting lowland dipterocarp forests of Terengganu, Peninsular Malaysia. Trop Ecol 2022. [DOI: 10.1007/s42965-022-00267-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
AbstractA study was conducted to determine the species composition, density and feeding guild of birds at Tasik Kenyir and Setiu, Terengganu between June and September 2017 using line transect method. Observations of birds at Tasik Kenyir and Setiu recorded a total of 297 individuals consisting of 26 families from 64 species. This study estimated that the diversity of birds at Tasik Kenyir (H’ = 3.6) was higher compared to Setiu (H’ = 2.9). However, the density of birds at Setiu (52.05 ± 9.09 SE individuals/ha) was higher than Tasik Kenyir (37.56 ± 10.28 SE individuals/ha). Ten feeding guilds of birds were identified in this study; insectivore, nectarivore, frugivore, omnivore, carnivore, granivore, insectivore-nectarivore, insectivore-frugivore, insectivore-granivore and frugivore-granivore. This study has provided valuable information on the bird assemblage and the understanding on the distribution of birds at Tasik Kenyir and Setiu. It is highly recommended that further studies to be conducted at both sites with more sampling efforts in order to gain a more comprehensive baseline datasets for monitoring bird population trends and turnover between habitats.
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Kojima W. Fearless distasteful butterflies and timid mimetic butterflies: comparison of flight initiation distances in Papilioninae. Biol Lett 2022; 18:20220145. [PMID: 35538843 PMCID: PMC9091839 DOI: 10.1098/rsbl.2022.0145] [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: 03/21/2022] [Accepted: 04/21/2022] [Indexed: 11/12/2022] Open
Abstract
Prey are expected to flee from an approaching predator when the cost of remaining (i.e. being captured) exceeds the cost of fleeing. In species where individuals experience less predation pressure, delayed escape responses to predatory threats are predicted. Therefore, non-chalant behaviour should be observed in unpalatable and Batesian mimetic prey while rapid escape behaviour may be displayed in palatable and non-mimetic prey from closely related species. This study compared the flight initiation distances (FIDs; the distances at which a prey starts to flee during a standardized human approach) of several sympatric swallowtail butterflies (Papilionidae) in two areas with different temperate zones. As predicted, it was found that unpalatable species had significantly shorter FIDs than palatable species in both areas. By contrast, FIDs of Batesian mimic species were significantly longer than those of unpalatable model species and were not significantly different from those of palatable species. FIDs were not significantly different between mimetic and non-mimetic forms of the intraspecific polymorphic species Papilio polytes. The mimetic species or form may reduce the risk of revealing their identity (i.e. palatability) through early escape behaviour. These findings have implications for the selective forces that affect the escape tendency of prey.
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Affiliation(s)
- Wataru Kojima
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 7538511, Japan
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Dowdy NJ, Conner WE. Nonchalant Flight in Tiger Moths (Erebidae: Arctiinae) Is Correlated With Unpalatability. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00480] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Preferences for and use of light microhabitats differ among and within populations of a polytypic poison frog. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Anti-predator strategies can influence trade-offs governing other activities important to fitness. Crypsis, for example, might make conspicuous sexual display especially costly, whereas aposematism might reduce or remove such costs. We tested for correlates of anti-predator strategy in Oophaga pumilio, a polytypic poison frog with morphs spanning the crypsis–aposematism continuum. In the wild, males of visually conspicuous morphs display from conspicuous perches and behave as if they perceive predation risk to be low. We thus predicted that, given a choice of ambient light microhabitats, these males would use high ambient light conditions the most and be most likely to perch in high-light conditions. We found no evidence that differently colored male O. pumilio preferentially used bright microhabitats or that ambient light influenced perching in a morph-specific manner. Independent of light conditions, males from the most conspicuous population perched the least, but the most conspicuous individuals from a polymorphic population perched the most. These patterns suggest that preferences do not necessarily underlie among-morph differences observed in the wild. This could be explained, and remain consistent with theory, if risk aversion is shaped, in part, by experience.
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Sanchez E, Rodríguez A, Grau JH, Lötters S, Künzel S, Saporito RA, Ringler E, Schulz S, Wollenberg Valero KC, Vences M. Transcriptomic Signatures of Experimental Alkaloid Consumption in a Poison Frog. Genes (Basel) 2019; 10:genes10100733. [PMID: 31546679 PMCID: PMC6827147 DOI: 10.3390/genes10100733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/14/2019] [Accepted: 09/17/2019] [Indexed: 01/19/2023] Open
Abstract
In the anuran family Dendrobatidae, aposematic species obtain their toxic or unpalatable alkaloids from dietary sources, a process known as sequestering. To understand how toxicity evolved in this family, it is paramount to elucidate the pathways of alkaloid processing (absorption, metabolism, and sequestering). Here, we used an exploratory skin gene expression experiment in which captive-bred dendrobatids were fed alkaloids. Most of these experiments were performed with Dendrobates tinctorius, but some trials were performed with D. auratus, D. leucomelas and Allobates femoralis to explore whether other dendrobatids would show similar patterns of gene expression. We found a consistent pattern of up-regulation of genes related to muscle and mitochondrial processes, probably due to the lack of mutations related to alkaloid resistance in these species. Considering conserved pathways of drug metabolism in vertebrates, we hypothesize alkaloid degradation is a physiological mechanism of resistance, which was evidenced by a strong upregulation of the immune system in D. tinctorius, and of complement C2 across the four species sampled. Probably related to this strong immune response, we found several skin keratins downregulated, which might be linked to a reduction of the cornified layer of the epidermis. Although not conclusive, our results offer candidate genes and testable hypotheses to elucidate alkaloid processing in poison frogs.
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Affiliation(s)
- Eugenia Sanchez
- Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Ariel Rodríguez
- Institut fur Zoologie, Tierärztliche Hochschule Hannover, 30559 Hannover, Germany.
| | - Jose H Grau
- Museum für Naturkunde Berlin, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, 10115 Berlin, Germany.
| | - Stefan Lötters
- Biogeography Department, Trier University, 54296 Trier, Germany.
| | - Sven Künzel
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany.
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH 44118, USA.
| | - Eva Ringler
- Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, and University of Vienna, A-1210 Vienna, Austria.
- Department of Integrative Zoology, University of Vienna, A-1090 Vienna, Austria.
| | - Stefan Schulz
- Institute of Organic Chemistry, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
| | | | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
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Kalb N, Anger F, Randler C. Flight initiation distance and escape behavior in the black redstart (
Phoenicurus ochruros
). Ethology 2019. [DOI: 10.1111/eth.12867] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nadine Kalb
- Department of Biology Eberhard Karls University Tübingen Tübingen Germany
| | - Fabian Anger
- Department of Biology Eberhard Karls University Tübingen Tübingen Germany
| | - Christoph Randler
- Department of Biology Eberhard Karls University Tübingen Tübingen Germany
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Behavioural preference for low levels of UV-B radiation in two neotropical frog species from Costa Rica. JOURNAL OF TROPICAL ECOLOGY 2018. [DOI: 10.1017/s0266467418000287] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract:Tropical frogs experience damaging effects from exposure to UV-B radiation, and some diurnally active, conspicuous species exhibit avoidance behaviours to high levels of UV-B. To determine if similar behaviours are present in other diurnal frogs, we experimentally compared UV-B avoidance in two common species of neotropical diurnal frogs – Oophaga pumilio, an aposematic poison frog and Craugastor bransfordii, a cryptic leaf-litter frog – in response to different levels of UV-B. Wild-caught frogs were tested in experimental arenas fitted with filters that permitted two different levels of UV-B (low: 14% vs. high: 84% UV-B). Both species spent significantly more time under the low UV-B filter, suggesting that behavioural preferences for lower levels of UV-B are common to different diurnal species. Furthermore, male O. pumilio significantly preferred lower levels of UV-B, whereas females did not exhibit a preference for lower UV-B, which may suggest differences in UV-B exposure or sensitivity and/or alternative mechanism(s) to avoid UV-B between sexes. Although limited in scope, the findings of our study suggest that UV-B avoidance may be a behavioural adaptation common to all diurnal frogs.
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