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Ancillotto L, Falanga A, Agostinetto G, Tommasi N, Garonna AP, de Benedetta F, Bernardo U, Galimberti A, Conti P, Russo D. Predator-prey traits and foraging habitat shape the diet of a common insectivorous bat. ACTA OECOLOGICA 2023. [DOI: 10.1016/j.actao.2023.103890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Singh P, Grone N, Tewes LJ, Müller C. Chemical defense acquired via pharmacophagy can lead to protection from predation for conspecifics in a sawfly. Proc Biol Sci 2022; 289:20220176. [PMID: 35858054 PMCID: PMC9257289 DOI: 10.1098/rspb.2022.0176] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Chemical defense is a widespread anti-predator strategy exhibited by organisms, with individuals either synthesizing or extrinsically acquiring defensive chemicals. In some species, such defences can also be transferred among conspecifics. Here, we tested the effects of pharmacophagy on the defense capability of the turnip sawfly, Athalia rosae, which can acquire neo-clerodane diterpenoids (clerodanoids) via pharmacophagy when having access to the plant Ajuga reptans. We show that clerodanoid access mediates protection against predation by mantids for the sawflies, both in a no-choice feeding assay and a microcosm setup. Even indirect access to clerodanoids, via nibbling on conspecifics that had access to the plant, resulted in protection against predation albeit to a lower degree than direct access. Furthermore, sawflies that had no direct access to clerodanoids were consumed less frequently by mantids when they were grouped with conspecifics that had direct access. Most, but not all, of such initially undefended sawflies could acquire clerodanoids from conspecifics that had direct access to the plant, although in low quantities. Together our results demonstrate that clerodanoids serve as a chemical defense that can also be transferred by interactions among conspecifics. Moreover, the presence of chemically defended individuals in a group can confer protection onto conspecifics that had no direct access to clerodanoids.
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Affiliation(s)
- Pragya Singh
- Chemical Ecology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Neil Grone
- Chemical Ecology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Lisa Johanna Tewes
- Chemical Ecology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
| | - Caroline Müller
- Chemical Ecology, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld, Germany
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Kuga T, Seki M, Kasuya E, Satake A. An Evolutionary Game Model of Sex-Dependent Antipredator Signaling. Am Nat 2021; 198:489-505. [PMID: 34559613 DOI: 10.1086/715745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractVarious prey animals behave conspicuously to approaching predators. The conspicuous behavior is considered to be an antipredator signal, and the frequency of signaling individuals in a population differs between males and females in many species. We theoretically assessed the evolution of the inter- and intrasexual dimorphism in antipredator signaling by developing an evolutionary game model. We particularly focused on the Chinese grasshopper, Acrida cinerea, in which only a proportion of males and no females escape conspicuously. In our model, the antipredator signal was assumed to be costly and affect the probabilities of predation of both the signaling individual (individual effect) and the signaling or nonsignaling conspecifics around it (collective effect). The model indicates that (1) a positive individual effect is essential for the evolution of antipredator signaling; (2) sexual dimorphism in fecundity cost for signaling individuals or natural predation probability can produce intersexual dimorphism in the signaling where all individuals of one sex and no individuals of the other sex emit signal; and (3) a positive collective effect can explain the intrasexual dimorphism where only some individuals of one sex signal. This study provides the first model of intrasexual dimorphism in antipredator signaling and brings new testable predictions.
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Howell N, Sheard C, Koneru M, Brockelsby K, Ono K, Caro T. Aposematism in mammals. Evolution 2021; 75:2480-2493. [PMID: 34347894 DOI: 10.1111/evo.14320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 06/26/2021] [Accepted: 06/29/2021] [Indexed: 12/25/2022]
Abstract
Aposematic coloration is traditionally considered to signal unpalatability or toxicity. In mammals, most research has focused on just one form of defense, namely, noxious anal secretions, and its black-and-white advertisement as exemplified by skunks. The original formulation of aposematism, however, encompassed a broader range of morphological, physiological, and behavioral defenses, and there are many mammal species with black-and-white contrasting patterns that do not have noxious adaptations. Here, using Bayesian phylogenetic models and data from 1726 terrestrial nonvolant mammals we find that two aspects of conspicuous coloration, black-and-white coloration patterns on the head and body, advertise defenses that are morphological (spines, large body size), behavioral (pugnacity), and physiological (anal secretions), as well as being involved with sexual signaling and environmental factors linked to crypsis. Within Carnivora, defensive anal secretions are associated with complex black-and-white head patterns and longitudinal black-and-white body striping; in primates, larger bodied species exhibit irregular patches of black-and-white pelage; and in rodents, pugnacity is linked to sharp countershading and irregular blocks of white and black pelage. We show that black-and-white coloration in mammals is multifunctional, that it serves to warn predators of several defenses other than noxious anal secretions, and that aposematism in mammals is not restricted to carnivores.
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Affiliation(s)
- Natasha Howell
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, United Kingdom
| | - Catherine Sheard
- School of Earth Sciences, University of Bristol, Bristol, BS8 1TQ, United Kingdom
| | - Manisha Koneru
- Department of Ecology and Evolution, University of California, Davis, Davis, California, 95616
| | - Kasey Brockelsby
- Department of Ecology and Evolution, University of California, Davis, Davis, California, 95616
| | - Konatsu Ono
- Department of Animal Biology, University of California, Davis, Davis, California, 95616
| | - Tim Caro
- School of Biological Sciences, University of Bristol, Bristol, BS8 1TQ, United Kingdom.,Center for Population Biology, University of California, Davis, Davis, California, 95616
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Páez E, Valkonen JK, Willmott KR, Matos-Maraví P, Elias M, Mappes J. Hard to catch: experimental evidence supports evasive mimicry. Proc Biol Sci 2021; 288:20203052. [PMID: 33715434 DOI: 10.1098/rspb.2020.3052] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Most research on aposematism has focused on chemically defended prey, but the signalling difficulty of capture remains poorly explored. Similar to classical Batesian and Müllerian mimicry related to distastefulness, such 'evasive aposematism' may also lead to convergence in warning colours, known as evasive mimicry. A prime candidate group for evasive mimicry are Adelpha butterflies, which are agile insects and show remarkable colour pattern convergence. We tested the ability of naive blue tits to learn to avoid and generalize Adelpha wing patterns associated with the difficulty of capture and compared their response to that of birds that learned to associate the same wing patterns with distastefulness. Birds learned to avoid all wing patterns tested and generalized their aversion to other prey to some extent, but learning was faster with evasive prey compared to distasteful prey. Our results on generalization agree with longstanding observations of striking convergence in wing colour patterns among Adelpha species, since, in our experiments, perfect mimics of evasive and distasteful models were always protected during generalization and suffered the lowest attack rate. Moreover, generalization on evasive prey was broader compared to that on distasteful prey. Our results suggest that being hard to catch may deter predators at least as effectively as distastefulness. This study provides empirical evidence for evasive mimicry, a potentially widespread but poorly understood form of morphological convergence driven by predator selection.
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Affiliation(s)
- Erika Páez
- Institut de Systématique, Evolution, Biodiversité, Museum National d'Histoire Naturelle, CNRS, SU, EPHE, UA, Paris, France
| | - Janne K Valkonen
- Department of Biological and Environmental Science, University of Jyväskylä, Finland
| | - Keith R Willmott
- McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, USA
| | - Pável Matos-Maraví
- Biology Centre CAS, Institute of Entomology, Branišovská 31, České Budějovice, Czech Republic
| | - Marianne Elias
- Institut de Systématique, Evolution, Biodiversité, Museum National d'Histoire Naturelle, CNRS, SU, EPHE, UA, Paris, France
| | - Johanna Mappes
- Department of Biological and Environmental Science, University of Jyväskylä, Finland.,Organismal and Evolutionary Biology Research Program Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
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Cyriac VP, Kodandaramaiah U. Warning signals promote morphological diversification in fossorial uropeltid snakes (Squamata: Uropeltidae). Zool J Linn Soc 2020. [DOI: 10.1093/zoolinnean/zlaa062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Many species possess warning colourations that signal unprofitability to predators. Warning colourations are also thought to provide prey with a ‘predator-free space’ and promote niche expansion. However, how such strategies release a species from environmental constraints and facilitate niche expansion is not clearly understood. Fossoriality in reptiles imposes several morphological limits on head and body size to facilitate burrowing underground, but many fossorial snakes live close to the surface and occasionally move above ground, exposing them to predators. In such cases, evolving antipredator defences that reduce predation on the surface could potentially relax the morphological constraints associated with fossoriality and promote morphological diversification. Fossorial uropeltid snakes possess varying degrees of conspicuous warning colourations that reduce avian predation when active above ground. We predicted that species with more conspicuous colourations will exhibit more robust body forms and show faster rates of morphological evolution because constraints imposed by fossoriality are relaxed. Using a comparative phylogenetic approach on the genus Uropeltis, we show that more conspicuous species tend to have more robust morphologies and have faster rates of head-shape evolution. Overall, we find that the evolution of warning colourations in Uropeltis can facilitate niche expansion by influencing rates of morphological diversification.
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Affiliation(s)
- Vivek Philip Cyriac
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE) and School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, India
| | - Ullasa Kodandaramaiah
- IISER-TVM Centre for Research and Education in Ecology and Evolution (ICREEE) and School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Maruthamala P.O., Vithura, Thiruvananthapuram, India
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Cyriac VP, Kodandaramaiah U. Conspicuous colours reduce predation rates in fossorial uropeltid snakes. PeerJ 2019; 7:e7508. [PMID: 31428543 PMCID: PMC6698130 DOI: 10.7717/peerj.7508] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/17/2019] [Indexed: 01/04/2023] Open
Abstract
Uropeltid snakes (Family Uropeltidae) are non-venomous, fossorial snakes that are found above ground occasionally, during which time they are exposed to predation. Many species are brightly coloured, mostly on the ventral surface, but these colours are expected to have no function below the ground. Observations have shown that the cephalic resemblance (resemblance to heads) of uropeltid tails may direct attacks of predators towards the hardened tails, thereby potentially increasing handling times for predators. Experiments have also shown that predators learn to avoid prey that are non-toxic and palatable but are difficult to capture, hard to process or require long handling time when such prey advertise their unprofitability through conspicuous colours. We here postulate that uropeltid snakes use their bright colours to signal long handling times associated with attack deflection to the tails, thereby securing reduced predation from predators that can learn to associate colour with handling time. Captive chicken experiments with dough models mimicking uropeltids indicate that attacks were more common on the tail than on the head. Field experiments with uropeltid clay models show that the conspicuous colours of these snakes decrease predation rates compared to cryptic models, but a novel conspicuous colour did not confer such a benefit. Overall, our experiments provide support for our hypothesis that the conspicuous colours of these snakes reduce predation, possibly because these colours advertise unprofitability due to long handling times.
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Affiliation(s)
- Vivek Philip Cyriac
- IISER-TVM Centre for Research and Education in Ecology and Evolution and School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
| | - Ullasa Kodandaramaiah
- IISER-TVM Centre for Research and Education in Ecology and Evolution and School of Biology, Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, India
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