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Straub CS, Cuomo RG, Jimenez G. Habitat selection and refuge-use by a color polymorphic salamander reveal behavioral niche differences. Ecol Evol 2024; 14:e10978. [PMID: 38414572 PMCID: PMC10897528 DOI: 10.1002/ece3.10978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/28/2023] [Accepted: 01/10/2024] [Indexed: 02/29/2024] Open
Abstract
Color polymorphic species provide an excellent opportunity to investigate the ecology and evolution of intraspecific niche differences. The red-backed salamander, Plethodon cinereus, is a fully terrestrial lungless salamander with two common color forms, striped and unstriped. Previous research suggests the morphs may be differentially adapted to surface and subsurface microhabitats, with the unstriped morph being more fossorial. This hypothesis predicts that the unstriped morph should be more sensitive to the risks of surface activity (e.g., thermal stress, dehydration, predation), and therefore be more selective than striped morphs when choosing soil surface microhabitats. To test this hypothesis, we experimentally manipulated leaf litter mass in small forest patches (~0.45 m2). Leaf litter addition reduced soil temperatures, buffered against changes in air temperature, and likely provided physical protection from predators. Over 3 years, we found that unstriped adults responded positively to leaf litter addition, but striped adults did not. In addition, unstriped morphs spent significantly more time in protective refuges (opaque, moistened tubes) than striped morphs in laboratory assays. Taken together, the field and laboratory results support the hypothesis that the unstriped morph is more sensitive to the risks of surface activity, and therefore is more likely to be fossorial. This difference in microhabitat use, combined with spatiotemporal variation in leaf litter accumulation on the forest floor, may play an important role in the maintenance of the polymorphism.
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Affiliation(s)
- Cory S Straub
- Department of Biology Ursinus College Collegeville Pennsylvania USA
| | - Rosella G Cuomo
- Department of Biology Ursinus College Collegeville Pennsylvania USA
| | - Gabriel Jimenez
- Department of Biology Ursinus College Collegeville Pennsylvania USA
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2
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Buckingham E, Streicher JW, Fisher‐Reid MC, Jezkova T, Wiens JJ. Population genomic analyses support sympatric origins of parapatric morphs in a salamander. Ecol Evol 2022; 12:e9537. [PMCID: PMC9702563 DOI: 10.1002/ece3.9537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/31/2022] [Accepted: 11/07/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Emily Buckingham
- Department of Life Sciences The Natural History Museum London UK
- Department of Life Sciences Imperial College London (South Kensington) London UK
| | - Jeffrey W. Streicher
- Department of Life Sciences The Natural History Museum London UK
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona USA
| | - M. Caitlin Fisher‐Reid
- Department of Biological Sciences Bridgewater State University Bridgewater Massachusetts USA
| | | | - John J. Wiens
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona USA
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3
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Hantak MM, Guralnick RP, Zare A, Stucky BJ. Computer vision for assessing species color pattern variation from web-based community science images. iScience 2022; 25:104784. [PMID: 35982791 PMCID: PMC9379571 DOI: 10.1016/j.isci.2022.104784] [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: 02/21/2022] [Revised: 05/16/2022] [Accepted: 07/13/2022] [Indexed: 11/30/2022] Open
Abstract
Openly available community science digital vouchers provide a wealth of data to study phenotypic change across space and time. However, extracting phenotypic data from these resources requires significant human effort. Here, we demonstrate a workflow and computer vision model for automatically categorizing species color pattern from community science images. Our work is focused on documenting the striped/unstriped color polymorphism in the Eastern Red-backed Salamander (Plethodon cinereus). We used an ensemble convolutional neural network model to analyze this polymorphism in 20,318 iNaturalist images. Our model was highly accurate (∼98%) despite image heterogeneity. We used the resulting annotations to document extensive niche overlap between morphs, but wider niche breadth for striped morphs at the range-wide scale. Our work showcases key design principles for using machine learning with heterogeneous community science image data to address questions at an unprecedented scale. We built a deep learning model to group color morphs from community science images Our model achieved 98% accuracy for classifying striped and unstriped salamanders We used our model to classify >20,000 images and built morph-specific niche models We then determined if Red-backed salamanders niche partition at a range-wide scale
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Affiliation(s)
- Maggie M. Hantak
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
- Corresponding author
| | - Robert P. Guralnick
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
| | - Alina Zare
- Department of Electrical, and Computer Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Brian J. Stucky
- Florida Museum of Natural History, University of Florida, Gainesville, FL 32611, USA
- Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, USA
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Hantak MM, Federico NA, Blackburn DC, Guralnick RP. Rapid phenotypic change in a polymorphic salamander over 43 years. Sci Rep 2021; 11:22681. [PMID: 34811418 PMCID: PMC8609024 DOI: 10.1038/s41598-021-02124-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 11/10/2021] [Indexed: 11/30/2022] Open
Abstract
Color polymorphic animals offer a unique system for studying intraspecific phenotypic responses to climate change. Discrete color morphs are easy to identify, and correlated trait responses of morphs can indicate how climate warming may facilitate long-term maintenance of polymorphisms. We use a historical dataset spanning 43 years to examine temporal shifts in color morph frequency and body size in response to climate in the Eastern Red-backed Salamander, Plethodon cinereus, which contains a widespread striped/unstriped color polymorphism. We created a pipeline to extract high-throughput trait data from fluid-preserved museum specimens where we batch-photographed salamanders, de-aggregated individual specimens from photographs, and solicited help of community scientists to score color morphs. We used a linear modeling framework that includes information about spatial population structure to demonstrate that color morph frequency and body size vary in response to climate, elevation, and over time, with an overall trend of higher frequency and decreased body size of the striped morph, but increased size of the unstriped morph. These surprising results suggest that morphs may be responding to multiple climate and geographic drivers through co-adapted morphological changes. This work highlights new practices of extracting trait data from museum specimens to demonstrate species phenotypes response to climate change.
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Affiliation(s)
- Maggie M. Hantak
- grid.15276.370000 0004 1936 8091Florida Museum of Natural History, University of Florida, Gainesville, FL USA
| | - Nicholas A. Federico
- grid.15276.370000 0004 1936 8091Florida Museum of Natural History, University of Florida, Gainesville, FL USA
| | - David C. Blackburn
- grid.15276.370000 0004 1936 8091Florida Museum of Natural History, University of Florida, Gainesville, FL USA
| | - Robert P. Guralnick
- grid.15276.370000 0004 1936 8091Florida Museum of Natural History, University of Florida, Gainesville, FL USA
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Styga JM, Pienaar J, Scott PA, Earley RL. Does Body Shape in Fundulus Adapt to Variation in Habitat Salinity? Front Physiol 2019; 10:1400. [PMID: 31803063 PMCID: PMC6872640 DOI: 10.3389/fphys.2019.01400] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 10/30/2019] [Indexed: 01/29/2023] Open
Abstract
Understanding the ecological pressures that generate variation in body shape is important because body shape profoundly affects physiology and overall fitness. Using Fundulus, a genus of fish that exhibits considerable morphological and physiological variation with evidence of repeated transitions between freshwater and saltwater habitats, we tested whether habitat salinity has influenced the macroevolution of body shape at different stages in development. After accounting for phylogenetic inertia, we find that body shape deviates from the optimal streamlined shape in a manner consistent with different osmoregulatory pressures exerted by different salinity niches at every stage of ontogeny that we examined. We attribute variation in body shape to differential selection for osmoregulatory efficiency because: (1) saline intolerant species developed body shapes with relatively low surface areas more conducive to managing osmoregulatory demands and (2) inland species that exhibit high salinity tolerances have body shapes similar to saline tolerant species in marine environments.
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Affiliation(s)
- Joseph M Styga
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, United States.,Biology Program, Centre College, Danville, KY, United States
| | - Jason Pienaar
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, United States
| | - Peter A Scott
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, United States.,Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Ryan L Earley
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, United States
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6
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Kuchta SR. Richard Highton. COPEIA 2019. [DOI: 10.1643/ot-19-224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Shawn R. Kuchta
- Ohio Center for Ecological and Evolutionary Studies, Department of Biological Sciences, Ohio University, Irvine 107, Athens, Ohio 45701;
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7
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Jones KS, Weisrock DW. Genomic data reject the hypothesis of sympatric ecological speciation in a clade of Desmognathus salamanders. Evolution 2018; 72:2378-2393. [PMID: 30246244 DOI: 10.1111/evo.13606] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 09/05/2018] [Indexed: 12/22/2022]
Abstract
Closely related taxa with dissimilar morphologies are often considered to have diverged via natural selection favoring different phenotypes. However, some studies have found these scenarios to be paired with limited or no genetic differentiation. Desmognathus quadramaculatus and D. marmoratus are sympatric salamander species thought to represent a case of ecological speciation based on distinct morphologies, but the results of previous studies have not resolved corresponding patterns of lineage divergence. Here, we use genome-wide data to test this hypothesis of ecological speciation. Population structure analyses partitioned individuals geographically, but not morphologically, into two adjacent regions of western North Carolina: Pisgah and Nantahala. Phylogenetic analyses confirmed the nominal species are nonmonophyletic and resolved deep divergence between the two geographic clusters. Model-testing overwhelmingly supported the hypothesis that lineage divergence followed geography. Finally, ecological niche modeling showed that Pisgah and Nantahala individuals occupy different climatic niches, and geographic boundaries for the two lineages correspond to differences in precipitation regimes across southern Appalachia. Overall, we reject the previous hypothesis of ecological speciation based on microhabitat partitioning. Instead, our results suggest that there are two cryptic lineages, each containing the same pair of morphotypes.
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Affiliation(s)
- Kara S Jones
- Department of Biology, University of Kentucky, Lexington, Kentucky 40506
| | - David W Weisrock
- Department of Biology, University of Kentucky, Lexington, Kentucky 40506
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Cosentino BJ, Moore JD, Karraker NE, Ouellet M, Gibbs JP. Evolutionary response to global change: Climate and land use interact to shape color polymorphism in a woodland salamander. Ecol Evol 2017; 7:5426-5434. [PMID: 28770079 PMCID: PMC5528218 DOI: 10.1002/ece3.3118] [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: 03/13/2017] [Accepted: 05/02/2017] [Indexed: 01/09/2023] Open
Abstract
Evolutionary change has been demonstrated to occur rapidly in human‐modified systems, yet understanding how multiple components of global change interact to affect adaptive evolution remains a critical knowledge gap. Climate change is predicted to impose directional selection on traits to reduce thermal stress, but the strength of directional selection may be mediated by changes in the thermal environment driven by land use. We examined how regional climatic conditions and land use interact to affect genetically based color polymorphism in the eastern red‐backed salamander (Plethodon cinereus). P. cinereus is a woodland salamander with two primary discrete color morphs (striped, unstriped) that have been associated with macroclimatic conditions. Striped individuals are most common in colder regions, but morph frequencies can be variable within climate zones. We used path analysis to analyze morph frequencies among 238,591 individual salamanders across 1,170 sites in North America. Frequency of striped individuals was positively related to forest cover in populations occurring in warmer regions (>7°C annually), a relationship that was weak to nonexistent in populations located in colder regions (≤7°C annually). Our results suggest that directional selection imposed by climate warming at a regional scale may be amplified by forest loss and suppressed by forest persistence, with a mediating effect of land use that varies geographically. Our work highlights how the complex interaction of selection pressures imposed by different components of global change may lead to divergent evolutionary trajectories among populations.
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Affiliation(s)
| | - Jean-David Moore
- Direction de la recherche forestière Ministère des Forêts, de la Faune et des Parcs Québec City QC Canada
| | - Nancy E Karraker
- Department of Natural Resources Science University of Rhode Island Kingston RI USA
| | | | - James P Gibbs
- College of Environmental Science and Forestry State University of New York Syracuse NY USA
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Otaibi BW, Johnson QK, Cosentino BJ. Postautotomy tail movement differs between colour morphs of the red-backed salamander (Plethodon cinereus). AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Striped and unstriped colour morphs of the eastern red-backed salamander,Plethodon cinereus, vary in their pre-attack behavioural response to predators, but it is unknown whether the morphs vary in post-attack strategies. Both morphs employ tail autotomy, a post-attack defensive mechanism enabling an individual to release a portion of their tail to facilitate escape from predation. Postautotomy tail movement diverts attention of a predator away from the individual’s body, so natural selection should favor vigorous tail movement in both colour morphs ofP. cinereus. We compared the degree of postautotomy tail movement between morphs following simulated predation. Striped individuals exhibited substantially longer and faster tail movement than unstriped individuals. Divergence in postautotomy tail movement may be a direct evolved response to variable predation pressure between colour morphs. Alternatively, tail movement may be constrained in the unstriped morph due to a genetic correlation with colouration (e.g., pleiotropy).
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Affiliation(s)
- Banan W. Otaibi
- Department of Biology, Hobart and William Smith Colleges, Geneva, NY 14456, USA
| | - Quincey K. Johnson
- Department of Biology, Hobart and William Smith Colleges, Geneva, NY 14456, USA
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Stuczka A, Hickerson CA, Anthony C. Niche partitioning along the diet axis in a colour polymorphic population of Eastern Red-backed Salamanders, Plethodon cinereus. AMPHIBIA-REPTILIA 2016. [DOI: 10.1163/15685381-00003055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Eastern Red-backed Salamanders are colour polymorphic and have become a model system for examining ecological separation and the mechanisms for potential divergence in sympatry. Morphs of this species are differentiated along several niche axes including temperature optima, territorial behaviour, and response to predators. We were interested in whether temporal variation in ecological conditions would affect foraging behavior and ultimately diet. The goal of our study was to compare the diets of striped and unstripedP. cinereusover a range of seasonal conditions to better understand if the reported differences observed in the fall season at our field site remain consistent through the active season of this species. Diet differences between the two morphs were greatest during spring and fall when salamanders are most abundant at the surface. These diet differences were driven largely by two prey categories. In the spring, striped salamanders ate more oribatid mites and in the fall they consumed more entomobryomorph Collembola. Trade-offs associated with territory acquisition coupled with physiological and morphological differences may explain the observed seasonal niche partitioning related to the diet in this population.
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Affiliation(s)
- Angela Stuczka
- Department of Biology, John Carroll University, 1 John Carroll Blvd., University Heights, OH 44118, USA
| | - Cari-Ann Hickerson
- Department of Biology, John Carroll University, 1 John Carroll Blvd., University Heights, OH 44118, USA
| | - Carl Anthony
- Department of Biology, John Carroll University, 1 John Carroll Blvd., University Heights, OH 44118, USA
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