The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Takahiro Yajima - One of the best experts on this subject based on the ideXlab platform.
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Lotka–Volterra system and KCC theory: Differential geometric structure of competitions and Predations
Nonlinear Analysis-real World Applications, 2013Co-Authors: Kazuhito Yamasaki, Takahiro YajimaAbstract:Abstract We consider the differential geometric structure of competitions and Predations in the sense of the Lotka–Volterra system based on KCC theory. For this, we visualise the relationship between the Jacobi stability and the linear stability as a single diagram. We find the following. (I) Ecological interactions such as competition and Predation can be described by the deviation curvature. In this case, the sign of the deviation curvature depends on the type of interaction, which reflects the equilibrium point type. (II) The geometric quantities in KCC theory can be expressed in terms of the mean and Gaussian curvatures of the potential surface. In this particular case, the deviation curvature can be interpreted as the Willmore energy density of the potential surface. (III) When the equations of the system have nonsymmetric structure for the species (e.g. a Predation system), each species also has nonsymmetric geometric structure in the nonequilibrium region, but symmetric structure around the equilibrium point. These findings suggest that KCC theory is useful to establish the geometrisation of ecological interactions.
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lotka volterra system and kcc theory differential geometric structure of competitions and Predations
Nonlinear Analysis-real World Applications, 2013Co-Authors: Kazuhito Yamasaki, Takahiro YajimaAbstract:Abstract We consider the differential geometric structure of competitions and Predations in the sense of the Lotka–Volterra system based on KCC theory. For this, we visualise the relationship between the Jacobi stability and the linear stability as a single diagram. We find the following. (I) Ecological interactions such as competition and Predation can be described by the deviation curvature. In this case, the sign of the deviation curvature depends on the type of interaction, which reflects the equilibrium point type. (II) The geometric quantities in KCC theory can be expressed in terms of the mean and Gaussian curvatures of the potential surface. In this particular case, the deviation curvature can be interpreted as the Willmore energy density of the potential surface. (III) When the equations of the system have nonsymmetric structure for the species (e.g. a Predation system), each species also has nonsymmetric geometric structure in the nonequilibrium region, but symmetric structure around the equilibrium point. These findings suggest that KCC theory is useful to establish the geometrisation of ecological interactions.
Kazuhito Yamasaki - One of the best experts on this subject based on the ideXlab platform.
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Lotka–Volterra system and KCC theory: Differential geometric structure of competitions and Predations
Nonlinear Analysis-real World Applications, 2013Co-Authors: Kazuhito Yamasaki, Takahiro YajimaAbstract:Abstract We consider the differential geometric structure of competitions and Predations in the sense of the Lotka–Volterra system based on KCC theory. For this, we visualise the relationship between the Jacobi stability and the linear stability as a single diagram. We find the following. (I) Ecological interactions such as competition and Predation can be described by the deviation curvature. In this case, the sign of the deviation curvature depends on the type of interaction, which reflects the equilibrium point type. (II) The geometric quantities in KCC theory can be expressed in terms of the mean and Gaussian curvatures of the potential surface. In this particular case, the deviation curvature can be interpreted as the Willmore energy density of the potential surface. (III) When the equations of the system have nonsymmetric structure for the species (e.g. a Predation system), each species also has nonsymmetric geometric structure in the nonequilibrium region, but symmetric structure around the equilibrium point. These findings suggest that KCC theory is useful to establish the geometrisation of ecological interactions.
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lotka volterra system and kcc theory differential geometric structure of competitions and Predations
Nonlinear Analysis-real World Applications, 2013Co-Authors: Kazuhito Yamasaki, Takahiro YajimaAbstract:Abstract We consider the differential geometric structure of competitions and Predations in the sense of the Lotka–Volterra system based on KCC theory. For this, we visualise the relationship between the Jacobi stability and the linear stability as a single diagram. We find the following. (I) Ecological interactions such as competition and Predation can be described by the deviation curvature. In this case, the sign of the deviation curvature depends on the type of interaction, which reflects the equilibrium point type. (II) The geometric quantities in KCC theory can be expressed in terms of the mean and Gaussian curvatures of the potential surface. In this particular case, the deviation curvature can be interpreted as the Willmore energy density of the potential surface. (III) When the equations of the system have nonsymmetric structure for the species (e.g. a Predation system), each species also has nonsymmetric geometric structure in the nonequilibrium region, but symmetric structure around the equilibrium point. These findings suggest that KCC theory is useful to establish the geometrisation of ecological interactions.
Jinelle H. Sperry - One of the best experts on this subject based on the ideXlab platform.
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do seasonal patterns of rat snake pantherophis obsoletus and black racer coluber constrictor activity predict avian nest Predation
Ecology and Evolution, 2016Co-Authors: Jinelle H. Sperry, Brett A Degregorio, Michael P. WardAbstract:Avian nest success often varies seasonally and because Predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of snakes that are nest predators has lent some support to the link between snake activity and nest Predation. However, the strength of the relationship has varied among studies. Explaining this variation is difficult, because none of these studies directly identified nest predators, the link between predator activity and nest survival was inferred. To address this knowledge gap, we examined seasonal variation in daily survival rates of 463 bird nests (of 17 bird species) and used cameras to document predator identity at 137 nests. We simultaneously quantified seasonal activity patterns of two local snake species (N = 30 individuals) using manual (2136 snake locations) and automated (89,165 movements detected) radiotelemetry. Rat snakes (Pantherophis obsoletus), the dominant snake predator at the site (~28% of observed nest Predations), were most active in late May and early June, a pattern reported elsewhere for this species. When analyzing all monitored nests, we found no link between nest Predation and seasonal activity of rat snakes. When analyzing only nests with known predator identities (filmed nests), however, we found that rat snakes were more likely to prey on nests during periods when they were moving the greatest distances. Similarly, analyses of all monitored nests indicated that nest survival was not linked to racer activity patterns, but racer‐specific Predation (N = 17 nests) of filmed nests was higher when racers were moving the greatest distances. Our results suggest that the activity of predators may be associated with higher Predation rates by those predators, but that those effects can be difficult to detect when nest predator communities are diverse and predator identities are not known. Additionally, our results suggest that hand‐tracking of snakes provides a reliable indicator of predator activity that may be more indicative of foraging behavior than movement frequency provided by automated telemetry systems.
Jennifer L. Verdolin - One of the best experts on this subject based on the ideXlab platform.
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Meta-analysis of foraging and Predation risk trade-offs in terrestrial systems
Behavioral Ecology and Sociobiology, 2006Co-Authors: Jennifer L. VerdolinAbstract:Although there is ample evidence for the generality of foraging and Predation trade-offs in aquatic systems, its application to terrestrial systems is less comprehensive. In this review, meta-analysis was used to analyze experiments on giving-up-densities in terrestrial systems to evaluate the overall magnitude of Predation risk on foraging behavior and experimental conditions mediating its effect. Results indicate a large and significant decrease in foraging effort as a consequence of increased Predation risk. Whether experiments were conducted under natural or artificial conditions produced no change in the overall effect Predation had on foraging. Odor and live predators as a correlate of Predation risk had weaker and nonsignificant effects compared to habitat characteristics. The meta-analysis suggests that the effect of Predation risk on foraging behavior in terrestrial systems is strongly dependent on the type of Predation risk being utilized.
Brett A Degregorio - One of the best experts on this subject based on the ideXlab platform.
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do seasonal patterns of rat snake pantherophis obsoletus and black racer coluber constrictor activity predict avian nest Predation
Ecology and Evolution, 2016Co-Authors: Jinelle H. Sperry, Brett A Degregorio, Michael P. WardAbstract:Avian nest success often varies seasonally and because Predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of snakes that are nest predators has lent some support to the link between snake activity and nest Predation. However, the strength of the relationship has varied among studies. Explaining this variation is difficult, because none of these studies directly identified nest predators, the link between predator activity and nest survival was inferred. To address this knowledge gap, we examined seasonal variation in daily survival rates of 463 bird nests (of 17 bird species) and used cameras to document predator identity at 137 nests. We simultaneously quantified seasonal activity patterns of two local snake species (N = 30 individuals) using manual (2136 snake locations) and automated (89,165 movements detected) radiotelemetry. Rat snakes (Pantherophis obsoletus), the dominant snake predator at the site (~28% of observed nest Predations), were most active in late May and early June, a pattern reported elsewhere for this species. When analyzing all monitored nests, we found no link between nest Predation and seasonal activity of rat snakes. When analyzing only nests with known predator identities (filmed nests), however, we found that rat snakes were more likely to prey on nests during periods when they were moving the greatest distances. Similarly, analyses of all monitored nests indicated that nest survival was not linked to racer activity patterns, but racer‐specific Predation (N = 17 nests) of filmed nests was higher when racers were moving the greatest distances. Our results suggest that the activity of predators may be associated with higher Predation rates by those predators, but that those effects can be difficult to detect when nest predator communities are diverse and predator identities are not known. Additionally, our results suggest that hand‐tracking of snakes provides a reliable indicator of predator activity that may be more indicative of foraging behavior than movement frequency provided by automated telemetry systems.
