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Barnett JB, Michalis C, Scott-Samuel NE, Cuthill IC. Colour pattern variation forms local background matching camouflage in a leaf-mimicking toad. J Evol Biol 2021; 34:1531-1540. [PMID: 34465010 DOI: 10.1111/jeb.13923] [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: 07/02/2021] [Revised: 08/17/2021] [Accepted: 08/26/2021] [Indexed: 12/26/2022]
Abstract
Optimal camouflage can, in principle, be relatively easily achieved in simple, homogeneous, environments where backgrounds always have the same colour, brightness and patterning. Natural environments are, however, rarely homogenous, and species often find themselves viewed against varied backgrounds where the task of concealment is more challenging. One result of variable backgrounds is the evolution of intraspecific phenotypic variation which may either be generalized, with multiple similarly cryptic patterns, or specialized, with each discrete colour form maximizing concealment against a single component of the background. We investigated the role of phenotypic variation in a highly variable population of the Neotropical toad Rhinella margaritifera using visual modelling and a computer-based detection task. We found that phenotypic variation was not divided into discrete colour morphs, and all toads were well camouflaged against the forest floor. However, although the whole population may appear to consist of random samples from the background, the toads were a particularly close match to the leaf litter, suggesting that they masquerade as dead leaves, which are themselves variable. Furthermore, rather than each colour form being equally effective against a single background, each toad was specialized towards its own particular local surroundings, as suggested by a specialist strategy. Taken together, these data highlight the importance of background matching to a nominally masquerading species, as well as how habitat heterogeneity at multiple spatial scales may affect the evolution of camouflage and phenotypic variation.
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Affiliation(s)
- James B Barnett
- School of Biological Sciences, University of Bristol, Bristol, UK.,Redpath Museum, McGill University, Montreal, QC, Canada.,Department of Psychology, Neuroscience, & Behaviour, McMaster University, Hamilton, ON, Canada
| | | | | | - Innes C Cuthill
- School of Biological Sciences, University of Bristol, Bristol, UK
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2
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Predation risk is a function of seasonality rather than habitat complexity in a tropical semiarid forest. Sci Rep 2021; 11:16670. [PMID: 34404872 PMCID: PMC8371019 DOI: 10.1038/s41598-021-96216-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/06/2021] [Indexed: 11/08/2022] Open
Abstract
Predator-prey dynamics are some of the most important species' interactions in the natural structuring of communities, and are among the more complex ecological processes studied by ecologists. We measured predation risk using artificial lizard replicas to test two competing hypotheses regarding predation pressure in semi-arid environments: (1) predation risk is dependent on the habitat structural complexity; and (2) predation risk is dependent on seasonality. We placed 960 lizard replicas along three sites with different physical structures and in both dry and rainy seasons for seven consecutive days in a caatinga area in northeastern Brazil at Grota do Angico Natural Monument (GANM). Birds were responsible for the majority of attacks and more frequently on artificial lizards placed in trees. Attacks focused on the most vulnerable areas of the body (head and torso), proving that were perceived by predators as true prey items. We found that predation risk is not dependent on the habitat structural complexity, but rather dependent on the caatinga seasonality, with the overall attack rate being 19% higher in the dry season. Our study suggests that potential predation risk is highly context-dependent and that seasonality consistently drives of trophic interactions strength in the caatinga, an important ecological finding that could contribute to better understanding the complex evolution of predator-prey interactions within communities of animals living in different habitats.
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3
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The Influence of Environmental and Physiological Factors on Variation in American Toad (Anaxyrus americanus) Dorsal Coloration. J HERPETOL 2021. [DOI: 10.1670/20-093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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4
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Rich C, Reilly SB, Sinervo B. Relaxed predation selection on rare morphs of Ensatina salamanders (Caudata: Plethodontidae) promotes a polymorphic population in a novel dune sand habitat. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blaa211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The ring species Ensatina represents a classic example of locally adapted lineages. The Monterey ensatina (Ensatina eschscholtzii eschscholtzii) is a cryptic subspecies with brown coloration, although a recently discovered polymorphic population within a wind-blown sand region also contains leucistic (pink) and xanthistic (orange) morphs. In the present study, the frequency of leucism/xanthism was mapped across the subspecies’ range, revealing that these morphs are generally rare or absent except within regions containing light-coloured substrate. Attack rates were estimated using clay models of the three morphs, deployed only at the crepuscular period and during the night, on both light and dark substrates at a site within the dune sand region. Model selection found that the interaction between morph and substrate colour best predicted attack rates. Typical morphs had equal attack rates on both substrates while xanthistic and leucistic morphs incurred significantly fewer attacks on light vs. dark substrate, and there was no significant difference in attack rates among morphs on light substrates. These results support the idea that xanthistic and leucistic morphs are poorly adapted for dark substrates compared to typical morphs, but they are more or less equally adapted for light substrates. We suggest that this microgeographic island of relaxed selection on light-coloured morphs helps to explain the existence of this polymorphic population.
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Affiliation(s)
- Caitlyn Rich
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Sean B Reilly
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
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5
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Bu R, Xiao F, Lovell PG, Ye Z, Shi H. Structural and colored disruption as camouflage strategies in two sympatric Asian box turtle species (Cuora spp.). Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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6
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Umbers KDL, Riley JL, Kelly MBJ, Taylor‐Dalton G, Lawrence JP, Byrne PG. Educating the enemy: Harnessing learned avoidance behavior in wild predators to increase survival of reintroduced southern corroboree frogs. CONSERVATION SCIENCE AND PRACTICE 2019. [DOI: 10.1111/csp2.139] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Kate D. L. Umbers
- School of Science and HealthWestern Sydney University Richmond New South Wales Australia
- Hawkesbury Institute for the EnvironmentWestern Sydney University Richmond New South Wales Australia
| | - Julia L. Riley
- Department of Botany & ZoologyStellenbosch University Stellenbosch South Africa
| | - Michael B. J. Kelly
- School of Science and HealthWestern Sydney University Richmond New South Wales Australia
- Hawkesbury Institute for the EnvironmentWestern Sydney University Richmond New South Wales Australia
| | - Griffin Taylor‐Dalton
- School of Science and HealthWestern Sydney University Richmond New South Wales Australia
| | | | - Phillip G. Byrne
- School of BiologyUniversity of Wollongong Wollongong New South Wales Australia
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7
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Anderson NK, Gutierrez SO, Bernal XE. From forest to city: urbanization modulates relative abundance of anti-predator coloration. JOURNAL OF URBAN ECOLOGY 2019. [DOI: 10.1093/jue/juz016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Abstract
Increased urbanization has resulted in community changes including alteration of predator communities. Little is known, however, about how such changes affect morphological anti-predator traits. Given the importance of coloration in predator avoidance, this trait in particular is expected to be susceptible to novel selective environments in urban areas. Here, we investigate the coloration pattern of a Neotropical anuran species, the túngara frog (Engystomops pustulosus), along an urbanization gradient. Túngara frogs have two distinct color patterns (unstriped and striped) which we found to occur at different frequencies along an urbanization gradient. Striped individuals increased in frequency with urbanization. To assess the strength of selection imposed by predators on the two color morphs, we deployed clay models of túngara frogs in forest and semi-urban populations. In addition, we examined microhabitat selection by individuals of the different morphs. We found higher predation rates associated with urbanization than forested areas. In particular, frogs from forested habitats had lower number of attacks by avian predators. Contrary to our predictions, however, predation rates were similar for both color morphs independent of urbanization. Also, coloration of the frogs did not affect their microhabitat preference. Overall, túngara frogs are more likely to have a striped coloration pattern in semi-urban areas where predation by birds is higher than in the forest. Our findings suggest that factors other than predation pressure shape the coloration pattern of urban frogs and emphasize the complex nature of effects that anthropogenic changes in habitat and predator communities may have on prey morphology.
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Affiliation(s)
- Nigel K Anderson
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2054, USA
| | - Stephanie O Gutierrez
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2054, USA
| | - Ximena E Bernal
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47907-2054, USA
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panamá, República de Panamá
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8
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McElroy MT, Donoso DA. Ant Morphology Mediates Diet Preference in a Neotropical Toad (Rhinella alata). COPEIA 2019. [DOI: 10.1643/ch-18-162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Matthew T. McElroy
- Environmental Science, Policy, and Management, University of California, Berkeley, California 94720;
| | - David A. Donoso
- Departamento de Biología, Escuela Politécnica Nacional, Quito, Ecuador; . Send reprint requests to this address
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9
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Akcali CK, Adán Pérez-Mendoza H, Salazar-Valenzuela D, Kikuchi DW, Guayasamin JM, Pfennig DW. Evaluating the utility of camera traps in field studies of predation. PeerJ 2019; 7:e6487. [PMID: 30828493 PMCID: PMC6394347 DOI: 10.7717/peerj.6487] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/19/2019] [Indexed: 11/29/2022] Open
Abstract
Artificial prey techniques—wherein synthetic replicas of real organisms are placed in natural habitats—are widely used to study predation in the field. We investigated the extent to which videography could provide additional information to such studies. As a part of studies on aposematism and mimicry of coral snakes (Micrurus) and their mimics, observational data from 109 artificial snake prey were collected from video-recording camera traps in three locations in the Americas (terra firme forest, Tiputini Biodiversity Station, Ecuador; premontane wet forest, Nahá Reserve, Mexico; longleaf pine forest, Southeastern Coastal Plain, North Carolina, USA). During 1,536 camera days, a total of 268 observations of 20 putative snake predator species were recorded in the vicinity of artificial prey. Predators were observed to detect artificial prey 52 times, but only 21 attacks were recorded. Mammals were the most commonly recorded group of predators near replicas (243) and were responsible for most detections (48) and attacks (20). There was no difference between avian or mammalian predators in their probability of detecting replicas nor in their probability of attacking replicas after detecting them. Bite and beak marks left on clay replicas registered a higher ratio of avian:mammalian attacks than videos registered. Approximately 61.5% of artificial prey monitored with cameras remained undetected by predators throughout the duration of the experiments. Observational data collected from videos could provide more robust inferences on the relative fitness of different prey phenotypes, predator behavior, and the relative contribution of different predator species to selection on prey. However, we estimate that the level of predator activity necessary for the benefit of additional information that videos provide to be worth their financial costs is achieved in fewer than 20% of published artificial prey studies. Although we suggest future predation studies employing artificial prey to consider using videography as a tool to inspire new, more focused inquiry, the investment in camera traps is unlikely to be worth the expense for most artificial prey studies until the cost:benefit ratio decreases.
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Affiliation(s)
- Christopher K Akcali
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | | | | | - David W Kikuchi
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA
| | - Juan M Guayasamin
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Quito, Ecuador
| | - David W Pfennig
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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10
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Bruinjé AC, Moura MO, Maggi BS, São-Pedro VA, Pessoa DM, Costa GC. Conspecifics of the Striped Lava Lizard are able to distinguish sex and male colour morphs in apparently homogeneous dull dorsal colouration. AMPHIBIA-REPTILIA 2019. [DOI: 10.1163/15685381-20181048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat’s UV reflection might have a cost infringed by conspicuousness.
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Affiliation(s)
- Andre C. Bruinjé
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Mauricio O. Moura
- 1Graduate Program in Ecology and Conservation Biology, Department of Zoology, Universidade Federal do Paraná, Curitiba, Paraná, Brazil
| | - Bruno S. Maggi
- 2Laboratory of Biogeography, Macroecology and Evolutionary Biology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Vinicius A. São-Pedro
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- 4Centro de Ciências da Natureza, Universidade Federal de São Carlos, Campus Lagoa do Sino, Buri, São Paulo, Brazil
| | - Daniel M.A. Pessoa
- 3Laboratory of Sensory Ecology, Department of Physiology, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Gabriel C. Costa
- 5Department of Biology, Auburn University at Montgomery, Montgomery, AL 36124, USA
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11
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Bordignon DW, Caorsi VZ, Colombo P, Abadie M, Brack IV, Dasoler BT, Borges-Martins M. Are the unken reflex and the aposematic colouration of Red-Bellied Toads efficient against bird predation? PLoS One 2018; 13:e0193551. [PMID: 29596437 PMCID: PMC5875753 DOI: 10.1371/journal.pone.0193551] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/13/2018] [Indexed: 11/19/2022] Open
Abstract
Aposematic signals as well as body behaviours may be important anti-predator defences. Species of the genus Melanophryniscus are characterised by having toxic lipophilic alkaloids in the skin and for presenting a red ventral colouration, which can be observed when they perform the behaviour called the unken reflex. Both the reflex behaviour and the colouration pattern are described as defence mechanisms. However, there are currently no studies testing their effectiveness against predators. This study aimed to test experimentally if both ventral conspicuous colouration and the unken reflex in Melanophryniscus cambaraensis function as aposematic signals against visually oriented predators (birds). We simulated the species studied using three different clay toad models as follows: (a) in a normal position with green coloured bodies, (b) in the unken reflex position with green coloured body and extremities and (c) in the unken reflex position with a green body and red extremities. Models were distributed on a known M. cambaraensis breeding site and in the adjacent forest. More than half of the attacks on the models were from birds; however, there was no preference for any model type. Thus, just the presence of the red colour associated with the motionless unken reflex position does not seem to prevent attacks from potential predators. It is possible that the effective aposematic signal in Melanophryniscus is achieved through the unken reflex movement together with the subsequent exhibition of the warning colouration and the secretion of toxins.
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Affiliation(s)
- Debora Wolff Bordignon
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
- * E-mail:
| | - Valentina Zaffaroni Caorsi
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Patrick Colombo
- Museu de Ciências Naturais, Fundação Zoobotânica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Michelle Abadie
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Ismael Verrastro Brack
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Bibiana Terra Dasoler
- Programa de Pós-Graduação em Ecologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
| | - Márcio Borges-Martins
- Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil
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12
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The effects of background coloration and dark spots on the risk of predation in poison frog models. Evol Ecol 2017. [DOI: 10.1007/s10682-017-9903-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Jones JA, Tisdale AC, Bakermans MH, Larkin JL, Smalling CG, Siefferman L. Multiple Plumage Ornaments as Signals of Intrasexual Communication in Golden‐Winged Warblers. Ethology 2017. [DOI: 10.1111/eth.12581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- John Anthony Jones
- Department of Ecology and Evolutionary Biology Tulane University New Orleans LA USA
- Department of Biology Appalachian State University Boone NC USA
| | - Anna C. Tisdale
- Department of Biology Appalachian State University Boone NC USA
| | - Marja H. Bakermans
- Department of Biology and Biotechnology Worcester Polytechnic Institute Worcester MA USA
| | - Jeffery L. Larkin
- Department of Biology Indiana University of Pennsylvania Indiana PA USA
| | | | - Lynn Siefferman
- Department of Biology Appalachian State University Boone NC USA
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14
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Kraemer AC, Serb JM, Adams DC. Both novelty and conspicuousness influence selection by mammalian predators on the colour pattern ofPlethodon cinereus(Urodela: Plethodontidae). Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12780] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew C. Kraemer
- Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames IA 50011 USA
| | - Jeanne M. Serb
- Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames IA 50011 USA
| | - Dean C. Adams
- Department of Ecology, Evolution, and Organismal Biology; Iowa State University; Ames IA 50011 USA
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