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Anderson TL, Burkhart JJ, Cianci‐Gaskill JA, Davenport JM. Limited population and community effects of hatching asynchrony in a pond‐breeding salamander. Ecosphere 2023. [DOI: 10.1002/ecs2.4372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Affiliation(s)
- Thomas L. Anderson
- Department of Biology Appalachian State University Boone North Carolina USA
| | - Jacob J. Burkhart
- Department of Biology Appalachian State University Boone North Carolina USA
| | | | - Jon M. Davenport
- Department of Biology Appalachian State University Boone North Carolina USA
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2
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Shidemantle G, Blackwood J, Horn K, Velasquez I, Ronan E, Reinke B, Hua J. The morphological effects of artificial light at night on amphibian predators and prey are masked at the community level. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 308:119604. [PMID: 35691446 DOI: 10.1016/j.envpol.2022.119604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Artificial light at night (ALAN) is a pervasive pollutant that influences wildlife at both the individual and community level. In this study, we tested the individual-level effects of ALAN on three species of tadpole prey and their newt predators by measuring prey pigmentation and predator and prey mass. Then we evaluated whether the individual-level effects of ALAN on pigmentation and mass had cascading community-level effects by assessing the outcome of predator-prey interactions. We found that spring peepers exposed to ALAN were significantly darker than those reared under control conditions. Additionally, wood frogs reared in ALAN conditions were significantly smaller than those reared in control conditions. In contrast, Eastern newts collected earlier in the spring that were exposed to ALAN were significantly larger than controls while those collected later in the spring were not affected by ALAN, suggesting phenological differences in the effect of ALAN. To understand how changes in pigmentation and size due to ALAN influence predation rates, we ran predation assays in both ALAN-polluted and ALAN-free outdoor environments. After the predation assay, the size disparity in wood frogs reared in ALAN was eliminated such that there was no longer a treatment difference in wood frog size, likely due to size-selective predation. This demonstrates the beneficial nature of predators' selective pressure on prey populations. Lastly, despite individual-level effects of ALAN on pigmentation and mass, we did not detect cascading community-level effects on predation rates. Overall, this study highlights important species-level distinctions in the effects of ALAN. It also emphasizes the need to incorporate ecological complexity to understand the net impact of ALAN.
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Affiliation(s)
| | - Jurnee Blackwood
- Binghamton University, 4400 Vestal Pkway East, Binghamton, NY, 13902, USA
| | - Kelsey Horn
- Binghamton University, 4400 Vestal Pkway East, Binghamton, NY, 13902, USA
| | - Isabela Velasquez
- Binghamton University, 4400 Vestal Pkway East, Binghamton, NY, 13902, USA
| | - Emily Ronan
- Binghamton University, 4400 Vestal Pkway East, Binghamton, NY, 13902, USA
| | - Beth Reinke
- Northeastern Illinois University, 5500 N St Louis Ave, Chicago, IL, 60625, USA
| | - Jessica Hua
- Binghamton University, 4400 Vestal Pkway East, Binghamton, NY, 13902, USA
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3
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Yang LH, Swan K, Bastin E, Aguilar J, Cenzer M, Codd A, Gonzalez N, Hayes T, Higgins A, Lor X, Macharaga C, McMunn M, Oto K, Winarto N, Wong D, Yang T, Afridi N, Aguilar S, Allison A, Ambrose‐Winters A, Amescua E, Apse M, Avoce N, Bastin K, Bolander E, Burroughs J, Cabrera C, Candy M, Cavett A, Cavett M, Chang L, Claret M, Coleman D, Concha J, Danzer P, DaRosa J, Dufresne A, Duisenberg C, Earl A, Eckey E, English M, Espejo A, Faith E, Fang A, Gamez A, Garcini J, Garcini J, Gilbert‐Igelsrud G, Goedde‐Matthews K, Grahn S, Guerra P, Guerra V, Hagedorn M, Hall K, Hall G, Hammond J, Hargadon C, Henley V, Hinesley S, Jacobs C, Johnson C, Johnson T, Johnson Z, Juchau E, Kaplan C, Katznelson A, Keeley R, Kubik T, Lam T, Lansing C, Lara A, Le V, Lee B, Lee K, Lemmo M, Lucio S, Luo A, Malakzay S, Mangney L, Martin J, Matern W, McConnell B, McHale M, McIsaac G, McLennan C, Milbrodt S, Mohammed M, Mooney‐McCarthy M, Morgan L, Mullin C, Needles S, Nunes K, O'Keeffe F, O'Keeffe O, Osgood G, Padilla J, Padilla S, Palacio I, Panelli V, Paulson K, Pearson J, Perez T, Phrakonekham B, Pitsillides I, Preisler A, Preisler N, Ramirez H, Ransom S, Renaud C, Rocha T, Saris H, Schemrich R, Schoenig L, Sears S, Sharma A, Siu J, Spangler M, Standefer S, Strickland K, Stritzel M, Talbert E, Taylor S, Thomsen E, Toups K, Tran K, Tran H, Tuqiri M, Valdes S, VanVorhis G, Vue S, Wallace S, Whipple J, Yang P, Ye M, Yo D, Zeng Y. Different factors limit early- and late-season windows of opportunity for monarch development. Ecol Evol 2022; 12:e9039. [PMID: 35845370 PMCID: PMC9273743 DOI: 10.1002/ece3.9039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 05/03/2022] [Accepted: 05/30/2022] [Indexed: 11/12/2022] Open
Abstract
Seasonal windows of opportunity are intervals within a year that provide improved prospects for growth, survival, or reproduction. However, few studies have sufficient temporal resolution to examine how multiple factors combine to constrain the seasonal timing and extent of developmental opportunities. Here, we document seasonal changes in milkweed (Asclepias fascicularis)-monarch (Danaus plexippus) interactions with high resolution throughout the last three breeding seasons prior to a precipitous single-year decline in the western monarch population. Our results show early- and late-season windows of opportunity for monarch recruitment that were constrained by different combinations of factors. Early-season windows of opportunity were characterized by high egg densities and low survival on a select subset of host plants, consistent with the hypothesis that early-spring migrant female monarchs select earlier-emerging plants to balance a seasonal trade-off between increasing host plant quantity and decreasing host plant quality. Late-season windows of opportunity were coincident with the initiation of host plant senescence, and caterpillar success was negatively correlated with heatwave exposure, consistent with the hypothesis that late-season windows were constrained by plant defense traits and thermal stress. Throughout this study, climatic and microclimatic variations played a foundational role in the timing and success of monarch developmental windows by affecting bottom-up, top-down, and abiotic limitations. More exposed microclimates were associated with higher developmental success during cooler conditions, and more shaded microclimates were associated with higher developmental success during warmer conditions, suggesting that habitat heterogeneity could buffer the effects of climatic variation. Together, these findings show an important dimension of seasonal change in milkweed-monarch interactions and illustrate how different biotic and abiotic factors can limit the developmental success of monarchs across the breeding season. These results also suggest the potential for seasonal sequences of favorable or unfavorable conditions across the breeding range to strongly affect monarch population dynamics.
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4
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Different time patterns of the presence of red-eared slider influence the ontogeny dynamics of common frog tadpoles. Sci Rep 2022; 12:7876. [PMID: 35552438 PMCID: PMC9098440 DOI: 10.1038/s41598-022-11561-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 04/20/2022] [Indexed: 11/09/2022] Open
Abstract
The coexistence of species in a given community depends on the set of species involved and the timing of their interactions. Many native communities are increasingly forced to face both direct and indirect pressures from new alien predators, which, in extreme cases, can lead to the extinction of prey populations. In this study, we examine the dynamics of the ontogeny of common frog (Rana temporaria) tadpoles under different time patterns of an alien predator-the red-eared slider (Trachemys scripta elegans) presence. We found that the tadpoles had a longer larval period and were smaller in size at metamorphosis and lower in body mass when the predator was present in early development than when the tadpoles developed without a predator. The early presence of a predator conspicuously reduced the growth increments of the tadpoles at early development. After the removal of the predator, growth accelerated above the level measured under the conditions of both the late predator and no predator. However, these growth rates did not exceed the growth rates of equally sized tadpoles in the other treatments and therefore were not sufficient to compensate for the growth slowdown in the first part of development. The presence of a predator in late tadpole development influenced neither the time to metamorphosis nor size/body mass at metamorphosis. In conclusion, the predator had the effect on metamorphosis traits only if it was present in the early development of tadpoles.
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5
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Rudolf VHW. Temperature and nutrient conditions modify the effects of phenological shifts in predator-prey communities. Ecology 2022; 103:e3704. [PMID: 35357008 DOI: 10.1002/ecy.3704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 11/10/2022]
Abstract
While there is mounting evidence indicating that the relative timing of predator and prey phenologies shapes the outcome of trophic interactions, we still lack a comprehensive understanding of how important the environmental context (e.g. abiotic conditions) is for shaping this relationship. Environmental conditions not only frequently drive shifts in phenologies, but they can also affect the very same processes that mediate the effects of phenological shifts on species interactions. Thus, identifying how environmental conditions shape the effects of phenological shifts is key to predict community dynamics across a heterogenous landscape and how they will change with ongoing climate change in the future. Here I tested how environmental conditions shape effects of phenological shifts by experimentally manipulating temperature, nutrient availability, and relative phenologies in two predator-prey freshwater systems (mole salamander- bronze frog vs dragonfly larvae-leopard frog). This allowed me to (1) isolate the effect of phenological shifts and different environmental conditions, (2) determine how they interact, and (3) how consistent these patterns are across different species and environments. I found that delaying prey arrival dramatically increased predation rates, but these effects were contingent on environmental conditions and predator system. While both nutrient addition and warming significantly enhanced the effect of arrival time, their effect was qualitatively different across systems: Nutrient addition enhanced the positive effect of early arrival in the dragonfly-leopard frog system, while warming enhanced the negative effect of arriving late in the salamander-bronze frog system. Predator responses varied qualitatively across predator-prey systems. Only in the system with strong gape-limitation were predators (salamanders) significantly affected by prey arrival time and this effect varied with environmental context. Correlations between predator and prey demographic rates suggest that this was driven by shifts in initial predator-prey size ratios and a positive feedback between size-specific predation rates and predator growth rates. These results highlight the importance of accounting for temporal and spatial correlation of local environmental conditions and gape-limitation in predator-prey systems when predicting the effects of phenological shifts and climate change on predator-prey systems.
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Affiliation(s)
- V H W Rudolf
- BioSciences, Rice University, Houston, Texas, USA
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6
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Multiple-Predator Effects and Functional Redundancy of Pond Predators. J HERPETOL 2022. [DOI: 10.1670/20-080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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The effects of intraguild interactions (or lack of) on prey diversity in experimental ponds food webs. FOOD WEBS 2021. [DOI: 10.1016/j.fooweb.2021.e00207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Anderson TL, Earl JE, Hocking DJ, Osbourn MS, Rittenhouse TAG, Johnson JR. Demographic effects of phenological variation in natural populations of two pond-breeding salamanders. Oecologia 2021; 196:1073-1083. [PMID: 34338861 DOI: 10.1007/s00442-021-05000-y] [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: 11/13/2019] [Accepted: 07/21/2021] [Indexed: 11/25/2022]
Abstract
Phenology is a key driver of population and community dynamics. Phenological metrics (e.g., first date that an event occurred) often simplify information from the full phenological distribution, which may undermine efforts to determine the importance of life history events. Data regarding full phenological distributions are especially needed as many species are shifting phenology with climatic change which can alter life-history patterns and species dynamics. We tested whether skewness, kurtosis or maximum duration of breeding phenology affected juvenile emigration phenology and survival in natural populations of ringed (Ambystoma annulatum) and spotted salamanders (A. maculatum) spanning a 7-year period at two study locations. We evaluated the relative importance of different phenological metrics in breeding phenology and larval density dependence on emigration phenology and survival. We found that variability in emigration phenology differed by species, with ringed salamanders having a shorter duration and distributions that were more often right-skewed and leptokurtic compared to spotted salamanders. Emigration phenology was not linked to any measure of variability in breeding phenology, indicating phenological variability operates independently across life stages and may be subject to stage-specific influences. Emigration duration and skewness were partially explained by larval density, which demonstrates how phenological distributions may change with species interactions. Further tests that use the full phenological distribution to link variability in timing of life history events to demographic traits such as survival are needed to determine if and how phenological shifts will impact species persistence.
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Affiliation(s)
- Thomas L Anderson
- Department of Biology, Appalachian State University, Boone, NC, 28608, USA.
- Department of Biology, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA.
| | - Julia E Earl
- School of Biological Sciences, Louisiana Tech University, Ruston, LA, 71272, USA
| | - Daniel J Hocking
- Biology Department, Frostburg State University, Frostburg, MD, 21532, USA
| | - Michael S Osbourn
- Department of Biology, Appalachian State University, Boone, NC, 28608, USA
| | - Tracy A G Rittenhouse
- Department of Natural Resources and the Environment, University of Connecticut, Storrs, CT, 06269, USA
| | - Jarrett R Johnson
- Biology Department, Western Kentucky University, Bowling Green, KY, 42101, USA
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9
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Giery ST, Drake DL, Urban MC. Microgeographic evolution of metabolic physiology in a salamander metapopulation. Ecology 2021; 102:e03488. [PMID: 34292592 DOI: 10.1002/ecy.3488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 05/16/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023]
Abstract
The Metabolic Theory of Ecology explains ecological variation spanning taxonomic organization, space, and time based on universal physiological relationships. The theory depends on two core parameters: the normalization constant, a mass-independent measure of metabolic rate expected to be invariant among similar species, and the scaling coefficient, a measure of metabolic change with body mass commonly assumed to follow the universal 3/4 scaling law. However, emerging evidence for adaptive microevolution of metabolic rates led us to hypothesize that metabolic rate might exhibit evolved variation among populations on microgeographic scales. To evaluate our hypothesis, we explored evidence for evolved variation in the scaling coefficient and normalization constant within a spotted salamander (Ambystoma maculatum) metapopulation in Connecticut, USA. We measured standard metabolic rate in common-garden raised spotted salamanders from 22 different populations and tested for the effects of six ecological variables suspected in advance to select for divergent physiology. We found that metabolic rate rose with body mass with a log-log slope of 0.97 that was statistically different from the expected 3/4 scaling law. Although we found no evidence for interpopulation variation in the scaling coefficient, we found evidence for interpopulation variation in the normalization constants among populations. Metabolic variation was best explained by differences in population density among ponds. Our results provide mixed support for Metabolic Theory of Ecology assumptions about parameter invariance and illustrate how fundamental physiological processes such as metabolic rate can evolve across microgeographic spatial scales.
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Affiliation(s)
- Sean T Giery
- Department of Ecology and Evolutionary Biology, Center of Biological Risk, University of Connecticut, Storrs, Connecticut, 06269, USA.,Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Dana L Drake
- Department of Ecology and Evolutionary Biology, Center of Biological Risk, University of Connecticut, Storrs, Connecticut, 06269, USA
| | - Mark C Urban
- Department of Ecology and Evolutionary Biology, Center of Biological Risk, University of Connecticut, Storrs, Connecticut, 06269, USA
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10
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Rudolf VHW, Eveland L. Ontogenetic diversity buffers communities against consequences of species loss. J Anim Ecol 2021; 90:1492-1504. [PMID: 33694228 DOI: 10.1111/1365-2656.13470] [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: 06/15/2020] [Accepted: 03/01/2021] [Indexed: 01/26/2023]
Abstract
Biodiversity can be measured at multiple organizational scales. While traditional studies have focused at taxonomic diversity, recent studies have emphasized the ecological importance of diversity within populations. However, it is unclear how these different scales of diversity interact to determine the consequence of species loss. Here we asked how predator diversity and presence of ontogenetic diversity within predator populations influences community structure. Ontogenetic diversity arises from shifts in the traits and ecology of individuals during ontogeny and it is one of the biggest sources of intraspecific diversity. However, whether it dampens or strengthens the negative consequences of with species loss is poorly understood. To study the interaction of species diversity and ontogenetic diversity, we experimentally manipulated predator species diversity and diversity of developmental stages within focal predator species and analysed their joint effect on predator and prey survival, biomass and prey community structure in experimental pond systems. While individual effects of ontogenetic diversity were often species specific, losing predator species from the community often had a much smaller or no effect on prey survival, biomass or community structure when all predator populations had high ontogenetic diversity. Thus, ontogenetic diversity within populations buffered against some of the consequences of biodiversity loss at higher organizational levels. Because the experiment controlled mean per capita size and biomass across structured versus unstructured populations, this pattern was not driven by differences in biomass of predators. Instead, results suggest that effects were driven by changes in the functional roles and indirect interactions across and within species. This indicates that even if all environmental conditions are similar, differences in the intrinsic structure of populations can modify the consequences of biodiversity loss. Together, these results revealed the importance of ontogenetic diversity within species for strengthening the resilience of natural communities to consequences of biodiversity loss and emphasize the need to integrate biodiversity patterns across organizational scales.
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11
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12
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Urban MC, Freidenfelds NA, Richardson JL. Microgeographic divergence of functional responses among salamanders under antagonistic selection from apex predators. Proc Biol Sci 2020; 287:20201665. [PMID: 33171095 DOI: 10.1098/rspb.2020.1665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
A predator's functional response determines predator-prey interactions by describing the relationship between the number of prey available and the number eaten. Its shape and parameters fundamentally govern the dynamic equilibrium of predator-prey interactions and their joint abundances. Yet, estimates of these key parameters generally assume stasis in space and time and ignore the potential for local adaptation to alter feeding responses and the stability of trophic dynamics. Here, we evaluate if functional responses diverge among populations of spotted salamander (Ambystoma maculatum) larvae that face antagonistic selection on feeding strategies based on their own risk of predation. Common garden experiments revealed that spotted salamander from ponds with varying predation risks differed in their functional responses, suggesting an evolutionary response. Applying mechanistic equations, we discovered that the combined changes in attack rates, handling times and shape of the functional response enhanced feeding rate in environments with high densities of gape-limited predators. We suggest how these parameter changes could alter community equilibria and other emergent properties of food webs. Community ecologists might often need to consider how local evolution at fine scales alters key relationships in ways that alter local diversity patterns, food web dynamics, resource gradients and community responses to disturbance.
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Affiliation(s)
- Mark C Urban
- Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA.,Center of Biological Risk, University of Connecticut, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA
| | - Nicole A Freidenfelds
- Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA.,Department of Natural Resources and the Environment, University of Connecticut, 1376 Storrs Road, Unit 4087, Storrs, CT 06269, USA
| | - Jonathan L Richardson
- Department of Ecology and Evolutionary Biology, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA.,Department of Biology, University of Richmond, Gottwald Science Center, 138 UR Drive, Richmond, VA, USA
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13
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Stemp KM, Anderson TL, Davenport JM. Macrogeographic variation of a pond predator's top‐down effects in a common garden environment. POPUL ECOL 2020. [DOI: 10.1002/1438-390x.12071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kenzi M. Stemp
- Department of Biology Appalachian State University Boone North Carolina USA
| | - Thomas L. Anderson
- Department of Biology Appalachian State University Boone North Carolina USA
| | - Jon M. Davenport
- Department of Biology Appalachian State University Boone North Carolina USA
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14
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Anderson TL, Stemp KM, Ousterhout BH, Burton D, Davenport JM. Impacts of phenological variability in a predatory larval salamander on pond food webs. J Zool (1987) 2019. [DOI: 10.1111/jzo.12733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- T. L. Anderson
- Department of Biology Southeast Missouri State University Cape Girardeau MO USA
- Department of Biology Appalachian State University Boone NC USA
| | - K. M. Stemp
- Department of Biology Southeast Missouri State University Cape Girardeau MO USA
- Department of Biology Appalachian State University Boone NC USA
| | - B. H. Ousterhout
- National Great Rivers Research and Education Center East Alton IL USA
| | - D. Burton
- Department of Biology Appalachian State University Boone NC USA
| | - J. M. Davenport
- Department of Biology Southeast Missouri State University Cape Girardeau MO USA
- Department of Biology Appalachian State University Boone NC USA
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15
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Cozzoli F, Gjoni V, Basset A. Size dependency of patch departure behavior: evidence from granivorous rodents. Ecology 2019; 100:e02800. [PMID: 31233618 PMCID: PMC6852180 DOI: 10.1002/ecy.2800] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 04/04/2019] [Accepted: 05/28/2019] [Indexed: 01/21/2023]
Abstract
Individual size is a major determinant of mobile organisms’ ecology and behavior. This study aims to explore whether allometric scaling principles can provide an underlying framework for general patterns of resource patch use. To this end, we used giving‐up densities (GUDs), that is, the amount of resources remaining in a patch after a forager has quit feeding, as a comparative measure of the amount of resources exploited by a forager of any given size. We specifically tested the hypothesis that size‐dependent responses to both internal (energy requirement) and external (risk management) forces may have an effect on GUDs. We addressed this topic by conducting an extensive meta‐analysis of published data on granivorous rodents, including 292 GUD measurements reported in 25 papers. The data set includes data on 22 granivorous rodent species belonging to three taxonomic suborders (Castorimorpha, Myomorpha, and Sciuromorpha) and spans three habitat types (desert, grassland, and forest). The observations refer to both patches subject to predation risk and safe patches. Pooling all data, we observed positive allometric scaling of GUDs with average forager size (scaling exponent = 0.45), which explained 15% of overall variance in individual GUDs. Perceived predation risk during foraging led to an increase in GUDs independently of forager size and taxonomy and of habitat type, which explained an additional 12% of overall GUD variance. The size scaling exponent of GUDs is positive across habitat types and taxonomic suborders of rodents. Some variation was observed, however. The scaling coefficients in grassland and forest habitat types were significantly higher than in the desert habitat type. In addition, Sciuromorpha and Myomorpha exhibited a more pronounced size scaling of GUDs than Castorimorpha. This suggests that different adaptive behaviors may be used in different contexts and/or from different foragers. With body size being a fundamental ecological descriptor, research into size scaling of GUDs may help to place patch‐use observations in a broader allometric framework.
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Affiliation(s)
- Francesco Cozzoli
- Department of Biological and Environmental Sciences and Technologies, University of the Salento, S.P. Lecce-Monteroni, Lecce, 73100, Italy
| | - Vojsava Gjoni
- Department of Biological and Environmental Sciences and Technologies, University of the Salento, S.P. Lecce-Monteroni, Lecce, 73100, Italy
| | - Alberto Basset
- Department of Biological and Environmental Sciences and Technologies, University of the Salento, S.P. Lecce-Monteroni, Lecce, 73100, Italy
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16
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Stretz P, Anderson TL, Burkhart JJ. Macroinvertebrate Foraging on Larval Ambystoma maculatum across Ontogeny. COPEIA 2019. [DOI: 10.1643/ch-18-140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Piper Stretz
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211-7400;
| | - Thomas L. Anderson
- Department of Biology, Appalachian State University, Boone, North Carolina 28608-2006;
| | - Jacob J. Burkhart
- Division of Biological Sciences, University of Missouri, Columbia, Missouri, 65211-7400; Present address: Department of Biology, Appalachian State University, Boone, North Carolina 28608-2006; . Send reprint requests t
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17
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Warming-induced shifts in amphibian phenology and behavior lead to altered predator-prey dynamics. Oecologia 2019; 189:803-813. [PMID: 30810801 DOI: 10.1007/s00442-019-04360-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 02/18/2019] [Indexed: 10/27/2022]
Abstract
Climate change-induced phenological variation in amphibians can disrupt time-sensitive processes such as breeding, hatching, and metamorphosis, and can consequently alter size-dependent interactions such as predation. Temperature can further alter size-dependent, predator-prey relationships through changes in species' behavior. We thus hypothesized that phenological shifts due to climate warming would alter the predator-prey dynamic in a larval amphibian community through changes in body size and behavior of both the predator and prey. We utilized an amphibian predator-prey system common to the montane wetlands of the U.S. Pacific Northwest: the long-toed salamander (Ambystoma macrodactylum) and its anuran prey, the Pacific chorus frog (Pseudacris regilla). We conducted predation trials to test if changes in predator phenology and environmental temperature influence predation success. We simulated predator phenological shifts using different size classes of the long-toed salamander representing an earlier onset of breeding while using spring temperatures corresponding to early and mid-season larval rearing conditions. Our results indicated that the predator-prey dynamic was highly dependent upon predator phenology and temperature, and both acted synergistically. Increased size asymmetry resulted in higher tadpole predation rates and tadpole tail damage. Both predators and prey altered activity and locomotor performance in warmer treatments. Consequently, behavioral modifications resulted in decreased survival rates of tadpoles in the presence of large salamander larvae. If predators shift to breed disproportionately earlier than prey due to climate warming, this has the potential to negatively impact tadpole populations in high-elevation amphibian assemblages through changes in predation rates mediated by behavior.
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18
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Schalk CM, Cove MV. Squamates as prey: Predator diversity patterns and predator-prey size relationships. FOOD WEBS 2018. [DOI: 10.1016/j.fooweb.2018.e00103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Urban MC, Zarnetske PL, Skelly DK. Searching for Biotic Multipliers of Climate Change. Integr Comp Biol 2018; 57:134-147. [PMID: 28881936 DOI: 10.1093/icb/icx045] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
SYNOPSIS As climates change, biologists need to prioritize which species to understand, predict, and protect. One way is to identify key species that are both sensitive to climate change and that disproportionately affect communities and ecosystems. These "biotic multipliers" provide efficient targets for research and conservation. Here, we propose eight mechanistic hypotheses related to impact and sensitivity that suggest that top consumers might often act as biotic multipliers of climate change. For impact, top consumers often affect communities and ecosystems through strong top-down effects. For sensitivity, metabolic theory and data suggest that photosynthesis and respiration differ in temperature responses, potentially increasing the sensitivity of consumers relative to plants. Larger-bodied organisms are typically more thermally sensitive than smaller ones, suggesting how large top consumers might be more sensitive than their smaller prey. In addition, traits related to predation are more sensitive than defensive traits to temperature. Top consumers might also be more sensitive because they often lag behind prey in phenological responses. The combination of low population sizes and demographic traits of top consumers could make them more sensitive to disturbances like climate change, which could slow their recovery. As top consumers are positioned at the top of the food chain, many small effects can accumulate from other trophic levels to affect top consumers. Finally, top consumers also often disperse more frequently and farther than prey, potentially leading to greater sensitivity to climate-induced changes in ranges and subsequent impacts on invaded communities. Overall, we expect that large, ectothermic top consumers and mobile predators might frequently be biotic multipliers of climate change. However, this prediction depends on the particular features of species, habitats, and ecosystems. In specific cases, herbivores, plants, or pathogens might be more sensitive than top consumers or have greater community impacts. To predict biotic multipliers, we need to compare sensitivities and impacts across trophic groups in a broader range of ecosystems as well as perform experiments that uncouple proposed mechanisms. Overall, the biotic multiplier concept offers an alternative prioritization scheme for research and conservation that includes impacts on communities and ecosystems.
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Affiliation(s)
- Mark C Urban
- Department of Ecology and Evolutionary Biology, Center of Biological Risk, University of Connecticut, 75 North Eagleville Rd., Unit 3043, Storrs, CT 06269, USA
| | - Phoebe L Zarnetske
- Department of Forestry, Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, 480 Wilson Rd, East Lansing, Michigan, USA
| | - David K Skelly
- Peabody Museum, Yale School of Forestry & Environmental Studies, Yale University, 195 Prospect St., New Haven, CT 06511, USA
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Rudolf VHW. Nonlinear effects of phenological shifts link interannual variation to species interactions. J Anim Ecol 2018; 87:1395-1406. [PMID: 29749640 DOI: 10.1111/1365-2656.12850] [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: 01/20/2018] [Accepted: 04/26/2018] [Indexed: 11/29/2022]
Abstract
The vast majority of species interactions are seasonally structured and depend on species' relative phenologies. However, differences in the phenologies of species naturally vary across years and are altered by ongoing climate change around the world. By combining experiments that shifted the relative hatching of two competing tadpole species across a productivity gradient with simulations of inter-annual variation in arrival times I tested how phenological variation across years can alter the strength and outcome of interspecific competition. Shifting the relative timing of hatching (phenology) of a species fundamentally altered interspecific competition, and the effect of shifting the timing on competition was highly non-linear for most demographic rates. Furthemore, this relationship varied with productivity of the system. As a consequence, (a) shifts in relative timing of phenologies had small or large effects depending on the average natural timing of interactions, and (b) changes in the inter-annual variation in onset of interaction alone can alter species interactions in simulations even when mean phenologies (timing) remain unchanged across years. Studies on phenologies traditionally focus on directional shifts in the mean of phenologies, but these results suggest that we also need to consider inter-annual variation in phenologies of interacting species to predict dynamics of natural communities and how they will be modified by climate change.
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Affiliation(s)
- Volker H W Rudolf
- Program in Ecology, & Evolutionary Biology, BioSciences, Rice University, Houston, Texas
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21
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Kindinger TL. Invasive predator tips the balance of symmetrical competition between native coral-reef fishes. Ecology 2018; 99:792-800. [PMID: 29490107 DOI: 10.1002/ecy.2173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/18/2017] [Accepted: 01/22/2018] [Indexed: 11/09/2022]
Abstract
The importance of competition and predation in structuring ecological communities is typically examined separately such that interactions between these processes are seldom understood. By causing large reductions in native prey, invasive predators may modify native species interactions. I conducted a manipulative field experiment in The Bahamas to investigate the possibility that the invasive Pacific red lionfish (Pterois volitans) alters competition between planktivorous fairy and blackcap basslets (Gramma loreto and Gramma melacara, respectively). Competition between these coral-reef fishes is known to have symmetrical effects on the juveniles of both species, whereby the feeding positions under reef ledges and growth rates of these individuals are hindered. Following baseline censuses of local populations of competing basslets, I simultaneously manipulated the abundance of lionfish on entire reefs, and the abundance of basslets in local populations under isolated ledges within each reef, resulting in three treatments: unmanipulated control populations of both basslets, reduced abundance of fairy basslet, and reduced abundance of blackcap basslet. For eight weeks, I measured the change in biomass and feeding position of 2-5 cm size classes of each basslet species and calculated the growth rates of ~2 cm individuals using a standard mark-and-recapture method. Experimental populations were filmed at dusk using automated video cameras to quantify the behavior of lionfish overlapping with basslets. Video playback revealed lionfish hunted across all ledge positions, regardless of which basslet species were present, yet lionfish differentially reduced the biomass of only juvenile (2 cm) fairy basslet. Predation reduced the effects of interspecific competition on juvenile blackcap basslet as evidenced by corresponding shifts in feeding position toward coveted front edges of ledges and increases in growth rates that were comparable to the response of these fish in populations where competition was experimentally reduced. Thus, an invasive marine predator altered the outcome of interspecific competition via differential predation, which tipped the balance of competition between native prey species from symmetrical to asymmetrical effects on juveniles. This study reveals a newly demonstrated context in which predation can indirectly facilitate prey, further broadening our understanding of the interactive effects of predation and competition in the context of invasive species.
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Affiliation(s)
- Tye L Kindinger
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, 97331, USA
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22
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Urban MC, Roehm R. The road to higher permanence and biodiversity in exurban wetlands. Oecologia 2017; 186:291-302. [DOI: 10.1007/s00442-017-3989-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 10/18/2017] [Indexed: 11/28/2022]
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Urban MC, Richardson JL, Freidenfelds NA, Drake DL, Fischer JF, Saunders PP. Microgeographic Adaptation of Wood Frog Tadpoles to an Apex Predator. COPEIA 2017. [DOI: 10.1643/cg-16-534] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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24
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Fiorino GE, McAdam AG. Local differentiation in the defensive morphology of an invasive zooplankton species is not genetically based. Biol Invasions 2017. [DOI: 10.1007/s10530-017-1530-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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25
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Burkhart JJ, Peterman WE, Brocato ER, Romine KM, Willis MMS, Ousterhout BH, Anderson TL, Drake DL, Rowland FE, Semlitsch RD, Eggert LS. The influence of breeding phenology on the genetic structure of four pond-breeding salamanders. Ecol Evol 2017; 7:4670-4681. [PMID: 28690797 PMCID: PMC5496555 DOI: 10.1002/ece3.3060] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 04/08/2017] [Accepted: 04/16/2017] [Indexed: 11/10/2022] Open
Abstract
Understanding metapopulation dynamics requires knowledge about local population dynamics and movement in both space and time. Most genetic metapopulation studies use one or two study species across the same landscape to infer population dynamics; however, using multiple co-occurring species allows for testing of hypotheses related to different life history strategies. We used genetic data to study dispersal, as measured by gene flow, in three ambystomatid salamanders (Ambystoma annulatum, A. maculatum, and A. opacum) and the Central Newt (Notophthalmus viridescens louisianensis) on the same landscape in Missouri, USA. While all four salamander species are forest dependent organisms that require fishless ponds to reproduce, they differ in breeding phenology and spatial distribution on the landscape. We use these differences in life history and distribution to address the following questions: (1) Are there species-level differences in the observed patterns of genetic diversity and genetic structure? and (2) Is dispersal influenced by landscape resistance? We detected two genetic clusters in A. annulatum and A. opacum on our landscape; both species breed in the fall and larvae overwinter in ponds. In contrast, no structure was evident in A. maculatum and N. v. louisianensis, species that breed during the spring. Tests for isolation by distance were significant for the three ambystomatids but not for N. v. louisianensis. Landscape resistance also contributed to genetic differentiation for all four species. Our results suggest species-level differences in dispersal ability and breeding phenology are driving observed patterns of genetic differentiation. From an evolutionary standpoint, the observed differences in dispersal distances and genetic structure between fall breeding and spring breeding species may be a result of the trade-off between larval period length and size at metamorphosis which in turn may influence the long-term viability of the metapopulation. Thus, it is important to consider life history differences among closely related and ecologically similar species when making management decisions.
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Affiliation(s)
- Jacob J Burkhart
- Division of Biological Sciences University of Missouri Columbia MO USA
| | - William E Peterman
- School of Environment and Natural Resources The Ohio State University Columbus OH USA
| | - Emily R Brocato
- Division of Biological Sciences University of Missouri Columbia MO USA
| | - Kimberly M Romine
- Division of Biological Sciences University of Missouri Columbia MO USA
| | | | | | | | - Dana L Drake
- Department of Ecology and Evolutionary Biology University of Connecticut Storrs CT USA
| | - Freya E Rowland
- Division of Biological Sciences University of Missouri Columbia MO USA
| | | | - Lori S Eggert
- Division of Biological Sciences University of Missouri Columbia MO USA
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Embryonic yolk removal affects neither morphology nor escape performance of larval axolotls. ZOOLOGY 2017; 122:7-15. [PMID: 28365231 DOI: 10.1016/j.zool.2017.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 01/02/2017] [Accepted: 03/06/2017] [Indexed: 11/24/2022]
Abstract
Maternal effects, the influences of maternal phenotype on the phenotypes of her offspring, mediate early ontogenetic traits through maternal investment. In amphibians, provisioning eggs with yolk is the main source of maternal investment. While larger eggs generally result in larger, higher-quality offspring, the relationship between egg size and offspring phenotype is complicated because offspring can evolve to be more or less responsive to variation in yolk provisions. Previous studies of several ambystomatid salamanders suggest that the effects of embryonic yolk reserve reduction on hatchling life history traits increase with egg size. In this study, a similar controlled experimental yolk removal technique in Ambystoma mexicanum was used to determine the effects of reduced yolk reserves on phenotypes including hatching time and stage, hatchling and larval size and performance in predation trials with fish. Surprisingly, yolk reduction revealed no effects on any traits. These findings suggest that larval morphology in A. mexicanum is highly canalized and larval phenotypes are decoupled from yolk reserve variation. This surprising lack of yolk removal effects in hatchling and larval axolotls illustrates the evolutionary flexibility of early life history traits. Traits can evolve to increase or decrease their response to resources and can even become completely unresponsive. Since we found no effects in early life history, we hypothesize that domestication of the axolotl may have altered yolk properties or allocation dynamics and that maternal investment in yolk reserves may manifest at later life stages by reducing the time to reproductive maturity or increasing fecundity.
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27
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Agonistic Behavior and Resource Defense among Sympatric Juvenile Pond-Breeding Salamanders. J HERPETOL 2016. [DOI: 10.1670/15-160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Seasonal Patterns of Intraguild Predation and Size Variation among Larval Salamanders in Ephemeral Ponds. J HERPETOL 2016. [DOI: 10.1670/15-029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Remmers W, Gameiro J, Schaberl I, Clausnitzer V. Elephant (Loxodonta africana) footprints as habitat for aquatic macroinvertebrate communities in Kibale National Park, south-west Uganda. Afr J Ecol 2016. [DOI: 10.1111/aje.12358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wolfram Remmers
- University of Koblenz-Landau; Universitaetsstr. 1 56070 Koblenz Germany
| | - João Gameiro
- Faculdade de Ciências da Universidade de Lisboa; 1749-016 Campo Grande Lisboa Portugal
| | | | - Viola Clausnitzer
- Senckenberg Museum of Natural History Görlitz; Am Museum 1 02826 Görlitz Germany
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Anderson T, Linares C, Dodson K, Semlitsch R. Variability in functional response curves among larval salamanders: comparisons across species and size classes. CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0149] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Predator species and body size represent critical factors that have differential effects on prey populations, as well as overall community structure. However, investigations of how morphologically-similar predator species, simultaneous to variation in predator body size, influence lower trophic levels are infrequently performed. We tested whether predator species and body size influenced the functional response curve of three larval ambystomatid salamanders (Ringed Salamander, Ambystoma annulatum Cope, 1886; Spotted Salamander, Ambystoma maculatum (Shaw, 1802); Marbled Salamander, Ambystoma opacum (Gravenhorst, 1807)) while eating congeneric prey. We combined larval salamanders of varying body sizes with up to six prey densities within experimental microcosms. We tested for the shape of the functional response curve and obtained parameter estimates for attack rate and handling time for each predator size – species combination. We found variability among both species and size classes, with a combination of type I and type II functional response curves. Large size classes of predators had higher attack rates than smaller size classes, but equivalently-sized larvae of different species exhibited differences in attack rates and handling time. Our study shows that predation risk varies depending on the size structure and diversity of predators present in a food web, and that grouping predators by either species or size class may reduce the ability to predict changes in community structure resulting from such interactions.
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Affiliation(s)
- T.L. Anderson
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
| | - C. Linares
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
| | - K.N. Dodson
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
| | - R.D. Semlitsch
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO 65211-7400, USA
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Anderson TL, Semlitsch RD. Top predators and habitat complexity alter an intraguild predation module in pond communities. J Anim Ecol 2015; 85:548-58. [PMID: 26476095 DOI: 10.1111/1365-2656.12462] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 10/01/2015] [Indexed: 11/28/2022]
Abstract
Predator diversity and habitat complexity frequently influence species interactions at lower trophic levels, yet their joint investigation has been performed infrequently despite the demonstrated importance of each individual factor. We investigated how different top predators and varying habitat complexity influence the function of an intraguild predation module consisting of two larval salamanders, intraguild predator Ambystoma annulatum and intraguild prey A. maculatum. We manipulated predator food webs and habitat complexity in outdoor mesocosms. Top predators significantly influenced body condition and survival of A. annulatum, but habitat complexity had minimal effects on either response. A three-way interaction among the covariates top predator identity, habitat complexity and A. annulatum survival influenced body condition and survival of A. maculatum via a density-mediated indirect effect. Different top predator combinations had variable effects in different habitat complexity treatments on intraguild predator (A. annulatum) survival that subsequently influenced intraguild prey (A. maculatum) body condition and survival. Future work should consider how different top predators influence other food web components, which should vary due to predator attributes and the physical environments in which they co-occur.
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Affiliation(s)
- Thomas L Anderson
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO, 65201, USA
| | - Raymond D Semlitsch
- Division of Biological Sciences, University of Missouri, 105 Tucker Hall, Columbia, MO, 65201, USA
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Anderson TL, Ousterhout BH, Peterman WE, Drake DL, Semlitsch RD. Life history differences influence the impacts of drought on two pond-breeding salamanders. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2015; 25:1896-1910. [PMID: 26591455 DOI: 10.1890/14-2096.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Drought is a strong density-independent environmental filter that contributes to population regulation and other ecological processes. Not all species respond similarly to drought, and the overall impacts can vary depending on life histories. Such differences can necessitate management strategies that incorporate information on individual species to maximize conservation success. We report the effects of a short-term drought on occupancy and reproductive success of two pond-breeding salamanders that differ in breeding phenology (fall vs. spring breeder) across an active military base landscape in Missouri, USA: We surveyed ~200 ponds for the presence of eggs, larvae, and metamorphs from 2011 to 2013. This period coincided with before, during, and after a severe drought that occurred in 2012. The two species showed contrasting responses to drought, where high reproductive failure (34% of ponds) was observed for the spring breeder during a single drought year. Alternatively, the fall breeder only showed a cumulative 8% failure over two years. The number of breeding ponds available for use in the fall decreased during the drought due to pond drying and/or a lack of re-filling. Estimates of occupancy probability declined for the fall-breeding salamander between 2012 and 2013, whereas occupancy probability estimates of the spring breeder increased post-drought. The presence of fish, hydroperiod, the amount of forest cover surrounding ponds, and canopy cover were all found to affect estimates of occupancy probabilities of each species. Pond clustering (distance to nearest pond and the number of ponds within close proximity), hydroperiod, forest cover, and canopy cover influenced both estimates of colonization and extinction probabilities. Our results show life history variation can be important in determining the relative susceptibility of a species to drought conditions, and that sympatric species experiencing the same environmental conditions can respond differently. Consideration of the spatial network and configuration of habitat patches that act as refuges under extreme environmental conditions will improve conservation efforts, such as the placement of permanent ponds for aquatic organisms. A better awareness of species-specific tolerances to environmental filters such as drought can lead to improved management recommendations to conserve and promote habitat for a greater diversity of species across landscapes of spatially connected populations.
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Abstract
Although natural populations consist of individuals with different traits, and the degree of phenotypic variation varies among populations, the impact of phenotypic variation on ecological interactions has received little attention, because traditional approaches to community ecology assume homogeneity of individuals within a population. Stage structure, which is a common way of generating size and developmental variation within predator populations, can drive cannibalistic interactions, which can affect the strength of predatory effects on the predator's heterospecific prey. Studies have shown that predator cannibalism weakens predatory effects on heterospecific prey by reducing the size of the predator population and by inducing less feeding activity of noncannibal predators. We predict, however, that predator cannibalism, by promoting rapid growth of the cannibals, can also intensify predation pressure on heterospecific prey, because large predators have large resource requirements and may utilize a wider variety of prey species. To test this hypothesis, we conducted an experiment in which we created carnivorous salamander (Hynobius retardatus) populations with different stage structures by manipulating the salamander's hatch timing (i.e., populations with large or small variation in the timing of hatching), and explored the resultant impacts on the abundance, behavior, morphology, and life history of the salamander's large heterospecific prey, Rana pirica frog tadpoles. Cannibalism was rare in salamander populations having small hatch-timing variation, but was frequent in those having large hatch-timing variation. Thus, giant salamander cannibals occurred only in the latter. We clearly showed that salamander giants exerted strong predation pressure on frog tadpoles, which induced large behavioral and morphological defenses in the tadpoles and caused them to metamorphose late at large size. Hence, predator cannibalism arising from large variation in the timing of hatching can strengthen predatory effects on heterospecific prey and can have impacts on various, traits of both predator and prey. Because animals commonly broaden their diet as they grow, such negative impacts of predator cannibalism on the heterospecific prey may be common in interactions between predators and prey species of similar size.
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Urban MC, Richardson JL. The evolution of foraging rate across local and geographic gradients in predation risk and competition. Am Nat 2015; 186:E16-32. [PMID: 26098352 DOI: 10.1086/681716] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Multiple theories predict the evolution of foraging rates in response to environmental variation in predation risk, intraspecific competition, time constraints, and temperature. We tested six hypotheses for the evolution of foraging rate in 24 spotted salamander (Ambystoma maculatum) populations from three latitudinally divergent sites using structural equation models derived from theory and applied to our system. We raised salamander larvae in a common-garden experiment and then assayed foraging rate under controlled conditions. Gape-limited predation risk from marbled salamanders solely explained foraging rate variation among populations at the southern site, which was dominated by this form of selection. However, at the middle and northern sites, populations evolved different foraging rates depending on their unique responses to local intraspecific density. The coupling of gape-limited predation risk from marbled salamanders and high intraspecific density at the middle site jointly contributed to selection for rapid foraging rate. At the northernmost site, intraspecific density alone explained 97% of the interpopulation variation in foraging rate. These results suggest that foraging rate has evolved multiple times in response to varying contributions from predation risk and intraspecific competition. Predation risk often varies along environmental gradients, and, thus, organisms might often shift evolutionary responses from minimizing predation risk to maximizing intraspecific competitive performance.
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Affiliation(s)
- Mark C Urban
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269
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37
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Miehls ALJ, Peacor SD, Valliant L, McAdam AG. Evolutionary stasis despite selection on a heritable trait in an invasive zooplankton. J Evol Biol 2015; 28:1091-102. [PMID: 25833682 DOI: 10.1111/jeb.12632] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/24/2015] [Accepted: 03/26/2015] [Indexed: 11/26/2022]
Abstract
Invasive species are one of the greatest threats to ecosystems, and there is evidence that evolution plays an important role in the success or failure of invasions. Yet, few studies have measured natural selection and evolutionary responses to selection in invasive species, particularly invasive animals. We quantified the strength of natural selection on the defensive morphology (distal spine) of an invasive zooplankton, Bythotrephes longimanus, in Lake Michigan across multiple months during three growing seasons. We used multiple lines of evidence, including historic and contemporary wild-captured individuals and palaeoecology of retrieved spines, to assess phenotypic change in distal spine length since invasion. We found evidence of temporally variable selection, with selection for decreased distal spine length early in the growing season and selection for increased distal spine length later in the season. This trend in natural selection is consistent with seasonal changes in the relative strength of non-gape-limited and gape-limited fish predation. Yet, despite net selection for increased distal spine length and a known genetic basis for distal spine length, we observed little evidence of an evolutionary response to selection. Multiple factors likely limit an evolutionary response to selection, including genetic correlations, trade-offs between components of fitness, and phenotypic plasticity.
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Affiliation(s)
- A L J Miehls
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA.,NOAA Great Lakes Environmental Research Laboratory, Ann Arbor, MI, USA
| | - S D Peacor
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
| | - L Valliant
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
| | - A G McAdam
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada
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Ousterhout BH, Anderson TL, Drake DL, Peterman WE, Semlitsch RD. Habitat traits and species interactions differentially affect abundance and body size in pond-breeding amphibians. J Anim Ecol 2015; 84:914-24. [PMID: 25643605 DOI: 10.1111/1365-2656.12344] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 01/26/2015] [Indexed: 12/01/2022]
Abstract
In recent studies, habitat traits have emerged as stronger predictors of species occupancy, abundance, richness and diversity than competition. However, in many cases, it remains unclear whether habitat also mediates processes more subtle than competitive exclusion, such as growth, or whether intra- and interspecific interactions among individuals of different species may be better predictors of size. To test whether habitat traits are a stronger predictor of abundance and body size than intra- and interspecific interactions, we measured the density and body size of three species of larval salamanders in 192 ponds across a landscape. We found that the density of larvae was best predicted by models that included habitat features, while models incorporating interactions among individuals of different species best explained the body size of larvae. Additionally, we found a positive relationship between focal species density and congener density, while focal species body size was negatively related to congener density. We posit that salamander larvae may not experience competitive exclusion and thus reduced densities, but instead compensate for increased competition behaviourally (e.g. reduced foraging), resulting in decreased growth. The discrepancy between larval density and body size, a strong predictor of fitness in this system, also highlights a potential shortcoming in using density or abundance as a metric of habitat quality or population health.
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Affiliation(s)
- Brittany H Ousterhout
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA
| | - Thomas L Anderson
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA
| | - Dana L Drake
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA
| | - William E Peterman
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA.,Illinois Natural History Survey, Prairie Research Institute, University of Illinois, 1916 S. Oak Street, Champaign, IL, 61820, USA
| | - Raymond D Semlitsch
- Division of Biological Sciences, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA
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Drake DL, Anderson TL, Smith LM, Lohraff KM, Semlitsch RD. Predation of Eggs and Recently Hatched Larvae of Endemic Ringed Salamanders (Ambystoma annulatum) by Native and Introduced Aquatic Predators. HERPETOLOGICA 2014. [DOI: 10.1655/herpetologica-d-14-00017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Anderson TL, Hocking DJ, Conner CA, Earl JE, Harper EB, Osbourn MS, Peterman WE, Rittenhouse TAG, Semlitsch RD. Abundance and phenology patterns of two pond-breeding salamanders determine species interactions in natural populations. Oecologia 2014; 177:761-773. [DOI: 10.1007/s00442-014-3151-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 11/10/2014] [Indexed: 11/28/2022]
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41
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Nosaka M, Katayama N, Kishida O. Feedback between size balance and consumption strongly affects the consequences of hatching phenology in size-dependent predator-prey interactions. OIKOS 2014. [DOI: 10.1111/oik.01662] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Megumi Nosaka
- Graduate School of Environmental Science, Hokkaido Univ.; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
| | - Noboru Katayama
- Teshio Experimental Forest, Field Center for Northern Biosphere, Hokkaido Univ.; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
| | - Osamu Kishida
- Teshio Experimental Forest, Field Center for Northern Biosphere, Hokkaido Univ.; Toikanbetsu, Horonobe JP-098-2943 Hokkaido Japan
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Miehls ALJ, Peacor SD, McAdam AG. GAPE-LIMITED PREDATORS AS AGENTS OF SELECTION ON THE DEFENSIVE MORPHOLOGY OF AN INVASIVE INVERTEBRATE. Evolution 2014; 68:2633-43. [PMID: 24916281 DOI: 10.1111/evo.12472] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 06/02/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea L. J. Miehls
- Department of Fisheries and Wildlife; Michigan State University; 480 Wilson Road East Lansing Michigan 48824
- NOAA Great Lakes Environmental Research Laboratory; 4840 South State Road Ann Arbor Michigan 48108
| | - Scott D. Peacor
- Department of Fisheries and Wildlife; Michigan State University; 480 Wilson Road East Lansing Michigan 48824
| | - Andrew G. McAdam
- Department of Integrative Biology; University of Guelph; Guelph Ontario N1G 2W1 Canada
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Davenport JM, Hossack BR, Lowe WH. Partitioning the non-consumptive effects of predators on prey with complex life histories. Oecologia 2014; 176:149-55. [DOI: 10.1007/s00442-014-2996-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 06/09/2014] [Indexed: 11/29/2022]
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Rudolf VHW, Rasmussen NL. Population structure determines functional differences among species and ecosystem processes. Nat Commun 2014; 4:2318. [PMID: 23933614 DOI: 10.1038/ncomms3318] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 07/17/2013] [Indexed: 11/09/2022] Open
Abstract
Linking the structure of communities to ecosystem functioning has been a perennial challenge in ecology. Studies on ecosystem function are traditionally focused on changes in species composition. However, this species-centric approach neglects the often dramatic changes in the ecology of organisms during their development, thereby limiting our ability to link the structure of populations and communities to the functioning of natural ecosystems. Here we experimentally demonstrate that the impact of organisms on community structure and ecosystem processes often differ more among developmental stages within a species than between species, contrary to current assumptions. Importantly, we show that functional differences between species vary depending on the specific demographic structure of predators. One important implication is that changes in the demography of populations can strongly alter the functional composition of communities and change ecosystem processes long before any species are extirpated from communities.
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Affiliation(s)
- Volker H W Rudolf
- Department of Ecology and Evolutionary Biology, Rice University, 6100 Main Street-MS 170, Houston, Texas 77005, USA.
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Davenport J, Seiwert P, Fishback L, Cash W. The effects of two fish predators on Wood Frog (Lithobates sylvaticus) tadpoles in a subarctic wetland: Hudson Bay Lowlands, Canada. CAN J ZOOL 2013. [DOI: 10.1139/cjz-2013-0091] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Fish can have strong predatory impacts on aquatic food webs. Indeed, fish are known to have strong effects on amphibians, with some species being excluded from communities where fish are present. Most research with amphibians and fish has focused on lower latitudes and very little is known of amphibian–fish interactions at higher latitudes. Therefore, we conducted an enclosure experiment in a subarctic natural wetland to examine the predatory effects of two species of fish, brook sticklebacks (Culaea inconstans (Cuvier, 1829)) and ninespine sticklebacks (Pungitius pungitius (L., 1758)), on the survival and growth of Wood Frogs (Lithobates sylvaticus (LeConte, 1825)). We found no significant difference in survival and size at metamorphosis among the two fish species treatments and fish-free treatments. We found that individuals from fish-free treatments metamorphosed earlier than those from either fish species present treatment. Our work suggests that stickleback fish predation may not have a major impact on Wood Frog tadpole survival and growth in a subarctic wetland. Sticklebacks may still have an impact on earlier developmental stages of Wood Frogs. This work begins to fill an important gap in potential factors that may impact larval amphibian survival and growth at higher latitudes.
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Affiliation(s)
- J.M. Davenport
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - P.A. Seiwert
- Department of Biology, University of Central Arkansas, Conway, AR 72035, USA
| | - L.A. Fishback
- Churchill Northern Studies Centre, Churchill, MB R0B 0E0, Canada
| | - W.B. Cash
- Department of Biology, University of Central Arkansas, Conway, AR 72035, USA
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High intraguild predator density induces thinning effects on and increases temporal overlap with prey populations. POPUL ECOL 2013. [DOI: 10.1007/s10144-013-0419-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Peterman WE, Anderson TL, Drake DL, Ousterhout BH, Semlitsch RD. Maximizing pond biodiversity across the landscape: a case study of larval ambystomatid salamanders. Anim Conserv 2013. [DOI: 10.1111/acv.12090] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- W. E. Peterman
- Division of Biological Sciences; University of Missouri; Columbia MO USA
| | - T. L. Anderson
- Division of Biological Sciences; University of Missouri; Columbia MO USA
| | - D. L. Drake
- Division of Biological Sciences; University of Missouri; Columbia MO USA
| | - B. H. Ousterhout
- Division of Biological Sciences; University of Missouri; Columbia MO USA
| | - R. D. Semlitsch
- Division of Biological Sciences; University of Missouri; Columbia MO USA
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48
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Jara FG, Úbeda CA, Perotti MG. Predatory insects in lentic freshwater habitats from northwest Patagonia: richness and phenology. J NAT HIST 2013. [DOI: 10.1080/00222933.2013.791932] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Oviposition Site Selection by Spotted Salamanders (Ambystoma maculatum) in an Isolated Wetland. J HERPETOL 2013. [DOI: 10.1670/11-179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Ecological and evolutionary mechanisms are increasingly thought to shape local community dynamics. Here, I evaluate if the local adaptation of a meso-predator to an apex predator alters local food webs. The marbled salamander (Ambystoma opacum) is an apex predator that consumes both the spotted salamander (Ambystoma maculatum) and shared zooplankton prey. Common garden experiments reveal that spotted salamander populations which co-occur with marbled salamanders forage more intensely than those that face other predator species. These foraging differences, in turn, alter the diversity, abundance and composition of zooplankton communities in common garden experiments and natural ponds. Locally adapted spotted salamanders exacerbate prey biomass declines associated with apex predation, but dampen the top-down effects of apex predation on prey diversity. Countergradient selection on foraging explains why locally adapted spotted salamanders exacerbate prey biomass declines. The two salamander species prefer different prey species, which explains why adapted spotted salamanders buffer changes in prey composition owing to apex predation. Results suggest that local adaptation can strongly mediate effects from apex predation on local food webs. Community ecologists might often need to consider the evolutionary history of populations to understand local diversity patterns, food web dynamics, resource gradients and their responses to disturbance.
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Affiliation(s)
- Mark C Urban
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Road, Unit 3043, Storrs, CT 06269, USA.
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