Towards understanding interactions in a complex world: Design and analysis of multi‐species functional response experiments

Methods in Ecology and Evolution, Journal Year: 2024, Volume and Issue: 15(9), P. 1704 - 1719

Published: June 23, 2024

Abstract The functional response describes feeding rates of consumers as a function resource density. While models for on single species are well studied and supported by large body empirical research, multiple ubiquitous in nature. However, laboratory experiments designed parameterizing multi‐species responses (MSFR) extremely rare, mainly due to logistical challenges the non‐trivial nature their statistical analysis. Here, we describe how these can be fitted data Bayesian framework. Specifically, address problem prey depletion during experiments, which accounted through dynamical modelling. In comprehensive simulation study, test effects experimental design, sample size noise level identifiability four distinct MSFR models. Additionally, demonstrate method's versatility applying it list datasets. We identify designs trials that produce most accurate parameter estimates two‐ three‐prey scenarios. Although introduces systematic bias estimates, model selection performs surprisingly MSFRs, almost always identifying correct even small This flexible framework allows simultaneous analysis from both single‐ multi‐prey scenarios, either with or without depletion. will help elucidate mechanisms such selectivity, switching implications food web stability biodiversity. Our approach equips researchers appropriate tools improve understanding interactions complex ecosystems.

Language: Английский

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Intraguild predation by a biocontrol predator is reduced at lower temperatures

Food Webs, Journal Year: 2025, Volume and Issue: unknown, P. e00397 - e00397

Published: April 1, 2025

Language: Английский

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Are type 3 functional responses just statistical apparitions?

Ecosphere, Journal Year: 2025, Volume and Issue: 16(4)

Published: April 1, 2025

Abstract Type 3 (sigmoidal) functional responses can protect rare prey from predation, but such are not often described. It is also clear that factors hypothesized to promote type responses, as predator–prey size ratios and higher temperatures, actually associated with curves, especially given experimental design concerns. Here, we assess support for 2 or a compilation of response experiments evaluate the role biology in generating responses. We find considerations generate models more than biological factors, after accounting effects, both ratio temperature increase models, line predictions. However, no factor explains much variation (full model R = 0.08). show standard selection cutoff one over other inconsistent across bootstrapped samples, indicating may emerge stochastically due noise foraging trial data. Finally, suggest conservative approach needed assessing models.

Language: Английский

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Food web functional responses

Frontiers in Ecology and Evolution, Journal Year: 2022, Volume and Issue: 10

Published: Aug. 9, 2022

This article reviews the nature of functional responses that have commonly been used to represent feeding relationships in ecological literature. It compares these with range response forms are likely characterize species natural communities. The latter set involves many more variables. history models, and examines previous work has allowed a predator single type prey depend on additional variables beyond abundance type. While number complex discussed over years, affecting rates still typically omitted from models food webs. influences trophic levels above or below particularly be ignored, although data suggested they can large effects response. adaptive behavior time-scale measurement also too often ignored. Some known unknown consequences omissions discussed.

Language: Английский

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A mechanistic model of functional response provides new insights into indirect interactions among arctic tundra prey

Ecology, Journal Year: 2022, Volume and Issue: 103(8)

Published: April 25, 2022

Prey handling processes are considered a dominant mechanism leading to short-term positive indirect effects between prey that share predator. However, growing body of research indicates predators not necessarily limited by such in the wild. Density-dependent changes predator foraging behavior can also generate but they rarely included as explicit functions densities functional response models. With aim untangling proximate mechanisms species interactions natural communities and improving our ability quantify interaction strength, we extended multi-prey version Holling disk equation including density-dependent behavior. Our model, based on traits behavior, was inspired vertebrate community arctic tundra, where main (the fox) is an active forager feeding primarily cyclic small rodent (lemming) eggs various tundra-nesting bird species. Short-term lemmings birds have been documented over circumpolar Arctic underlying remain poorly understood. We used unique data set, containing high-frequency GPS tracking, accelerometer, behavioral, experimental parameterize 15-year time series nesting success evaluate strength found (1) play minor role system (2) fox daily activity budget distance traveled partly explain predation release observed during lemming peaks. These adjustments with respect density thus appear commonly reported among tundra prey. components little studied deserve more attention improve interactions.

Language: Английский

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Functional Response of Harmonia axyridis to the Larvae of Spodoptera litura: The Combined Effect of Temperatures and Prey Instars

Frontiers in Plant Science, Journal Year: 2022, Volume and Issue: 13

Published: July 1, 2022

Functional responses are central to predator-prey dynamics and describe how predation varies with prey abundance. often measured without regard size (i.e., body mass) or the temperature dependence of feeding rates. However, variation in within populations is ubiquitous, rates both temperature-dependent. Here, we assessed functional larvae adult Harmonia axyridis on 1st, 2nd, 3rd instars Spodoptera litura across a range temperatures 15, 20, 25, 30, 35°C). The type parameters were determined using logistic regression fitted Roger's random predator equation. magnitude varied stage, but increased warming age. Predation by female 4th instar H. 1st was greater, followed 2nd S. litura. No occurred larger for axyridis. produced II (hyperbolic) response curve all three types they consumed. Space clearance rates, handling time, maximum changed size, increasing decreasing suggesting more will occur younger prey. This study indicates an interactive role prey/predator shaping responses, which might complicate planning effective biocontrol strategies against this serious pest.

Language: Английский

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Foraging rates from metabarcoding: Predators have reduced functional responses in wild, diverse prey communities

Ecology Letters, Journal Year: 2024, Volume and Issue: 27(3)

Published: March 1, 2024

Abstract Functional responses describe foraging rates across prey densities and underlie many fundamental ecological processes. Most functional response knowledge comes from simplified lab experiments, but we do not know whether these experiments accurately represent in nature. In addition, the difficulty of conducting multispecies means that it is unclear interaction strengths are weakened presence multiple types. We developed a novel method to estimate wild predators' metabarcoding data use this present for wolf spiders on 27 families. These field were considerably reduced compared responses. further find sometimes increased other types, contrary expectations. Our estimating will allow researchers determine predators address long‐standing questions about

Language: Английский

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Intraguild predation is increased in areas of low prey diversity in a generalist predator community

Journal of Animal Ecology, Journal Year: 2023, Volume and Issue: 92(4), P. 901 - 912

Published: Feb. 13, 2023

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 quantify diets from metabarcoding data has precluded the use of sequencing determine relative importance these mechanisms. Here, we pair recent quantification approach with stable isotope analysis examine diet composition wolf spider community. We compare prevalence resource partitioning IGP spiders test whether factors that influence foraging performance, including individual identity, morphology, prey community environmental conditions, explain variation IGP. Extensive likely primary this community, other often attributed do not here. Rather, increases as diversity decreases. Foragers are driven where niches limited. highlight need how drivers predator-prey interaction strengths translate into natural systems.

Language: Английский

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Functional responses of male and female European green crabs suggest potential sex-specific impacts of invasion

PeerJ, Journal Year: 2023, Volume and Issue: 11, P. e15424 - e15424

Published: June 2, 2023

Predicting the impacts of predatory invasive species is important for prioritising conservation interventions. Functional response experiments, which examine consumption by predators in relation to prey density, are a useful way assess potential strength novel predator-prey relationships. However, such experiments often conducted without consideration sex or only with males reduce invasion risk. Here, we compared functional responses male and female European green crabs ( Carcinus maenas ), global invader, feeding on varnish clams Nuttallia obscurata ) test whether two sexes have similar impact. We also examined correlates predation behaviour measuring sex-specific movement choice. Both displayed Type II hyperbolic response, can destabilise populations at low densities. females exhibited some differences foraging behaviour. Female had slightly lower attack rates, were not linked movement, longer handling times, These small, non-significant nevertheless translated into significantly greater ratios, used predict ecological impact species, than females. There was no difference proportion consumed between crusher claw heights, but smaller claws average, hence they clams. Repeated surveys four established British Columbia, Canada, showed that ratio highly variable. Taken together, these results population-level modelling suggest trying evaluate clam sampling could result overestimation, even male-biased sex-ratios. Consumer might generally be an feature consider when using forecast new especially those marked sexual dimorphism affect foraging.

Language: Английский

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Prey diversity constrains the adaptive potential of predator foraging traits

Oikos, Journal Year: 2021, Volume and Issue: 2022(1)

Published: Nov. 26, 2021

Predators are generally under selective pressure to get better at foraging, leading steeper functional responses and stronger predator–prey interactions. Yet strong interactions can de‐stabilize food webs, most across ecological communities thought be weak. This conflict between evolutionary community expectations for the strength of represents a fundamental gap in our understanding how evolution foraging plays out webs. Here we help resolve by showing analytically that expectation is relaxed with diverse prey types. We simulate varying richness show increasing indeed constrain adaptive potential predator traits, but low predators evolve have interaction high net energy yields. Our results also indicate handling time role determining whether may abundant prey, suggesting keystone modules webs likely when times negligible. provide new mechanism predicting more diffuse tropical relative species‐poor higher latitudes.

Language: Английский

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