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Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways, Kyle E. Coblentz, John P. Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the demographic or dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or the rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and dynamic consequences of evolution also can constrain …

Ecological Boundaries And Constraints On Viable Eco-Evolutionary Pathways, Kyle E. Coblentz, John P. Delong

School of Biological Sciences: Faculty Publications

Evolutionary dynamics are subject to constraints ranging from limitations on what is physically possible to limitations on the pathways that evolution can take. One set of evolutionary constraints, known as ‘demographic constraints’, constrain what can occur evolutionarily due to the demographic or dynamical consequences of evolution leading to conditions that make populations susceptible to extinction. These demographic constraints can limit the strength of selection or the rates of environmental change populations can experience while remaining extant and the trait values a population can express. Here we further hypothesize that the population demographic and dynamic consequences of evolution also can constrain …

Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F. Uiterwaal, Amber J. Squires, Bennett A. Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John P. Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community and environmental conditions, …

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Intraguild Predation Is Increased In Areas Of Low Prey Diversity In A Generalist Predator Community, Stella F Uiterwaal, Amber Squires, Bennett Grappone, Brian Dillard, Ariadne Castaneda, Sora L. Kim, John Delong

School of Biological Sciences: Faculty Publications

1. Niche differentiation and intraguild predation (IGP) can allow ecologically similar species to coexist, although it is unclear which coexistence mechanism predominates in consumer communities. Until now, a limited ability to quantify diets from metabarcoding data has precluded the use of sequencing data to determine the relative importance of these mechanisms.

2. Here, we pair a recent metabarcoding quantification approach with stable isotope analysis to examine diet composition in a wolf spider community.

3. We compare the prevalence of resource partitioning and IGP in these spiders and test whether factors that influence foraging performance, including individual identity, morphology, prey community …

Predator Feeding Rates May Often Be Unsaturated Under Typical Prey Densities, Kyle E. Coblentz, Mark Novak, John Delong

School of Biological Sciences: Faculty Publications

Predator feeding rates (described by their functional response) must saturate at high prey densities. Although thousands of manipulative functional response experiments show feeding rate saturation at high densities under controlled conditions, it remains unclear how saturated feeding rates are at natural prey densities. The general degree of feeding rate saturation has important implications for the processes determining feeding rates and how they respond to changes in prey density. To address this, we linked two databases—one of functional response parameters and one on mass–abundance scaling—through prey mass to calculate a feeding rate saturation index. We find that: (1) feeding rates may …

Quantifying Predator Functional Responses Under Field Conditions Reveals Interactive Effects Of Temperature And Interference With Sex And Stage, Kyle E. Coblentz, Amber Squires, Stella Uiterwaal, John Delong

School of Biological Sciences: Faculty Publications

1. Predator functional responses describe predator feeding rates and are central to predator–prey theory. Originally defined as the relationship between predator feeding rates and prey densities, it is now well known that functional responses are shaped by a multitude of factors. However, much of our knowledge about how these factors influence functional responses is based on laboratory studies that are generally logistically constrained to examining only a few factors simultaneously and that have unclear links to the conditions organisms experience in the field.
2. We apply an observational approach for measuring functional responses to understand how sex/stage differences, temperature and predator densities …

Predator-Dependent Functional Responses Alter The Coexistence And Indirect Effects Among Prey That Share A Predator, Kyle E. Coblentz, John P. Delong

School of Biological Sciences: Faculty Publications

Predator functional responses describe predator feeding rates as a function of prey abundance and are central to pred-ator–prey theory. Despite ample evidence that functional responses also depend on predator abundance, theory incor-porating predator-dependent functional responses has focused almost exclusively on specialist predator–prey pairs or linear food chains. This leaves a large gap in our knowledge as many predators feed on multiple prey, and in so doing, generate indirect effects among prey that can alter their coexistence. Here we investigate how predator-dependent functional responses in a one predator–two prey model alter the coexistence among prey and their net effects on one …