Empirical evidence of type III functional responses and why it remains rare

Frontiers in Ecology and Evolution, Journal Year: 2023, Volume and Issue: 11

Published: March 10, 2023

More than 70 years after its introduction, the framework of resource density-dependent consumption rates, also known as predator-prey functional responses, remains a core concept in population and food web ecology. Initially, three types responses were defined: linear (type I), hyperbolic II), sigmoid III). Due to potential stabilize consumer-resource dynamics, type III response immediately became “holy grail” However, experimentally proving that exist, whether controlled laboratory systems or nature, was challenging. While theoretical practical advances make identifying easier today, decades research have brought only limited number studies provide empirical evidence for curves. Here, we review this from laboratory- field-based published during last two decades. We found 107 reported but these ranged across various taxa, interaction types, ecosystems. To put into context, discuss biological mechanisms may lead emergence responses. summarize how different mutually independent intricacies bedevil documentation responses: (1) challenges statistical modeling (2) inadequate density ranges spacing, (3) biologically meaningful realistic design experimental arenas. Finally, guidelines on field should move forward based considerations.

Language: Английский

---

An Empiricist’s Guide to Using Ecological Theory

The American Naturalist, Journal Year: 2021, Volume and Issue: 199(1), P. 1 - 20

Published: Sept. 15, 2021

AbstractA scientific understanding of the biological world arises when ideas about how nature works are formalized, tested, refined, and then tested again. Although benefits feedback between theoretical empirical research widely acknowledged by ecologists, this link is still not as strong it could be in ecological research. This part because theory, particularly expressed mathematically, can feel inaccessible to empiricists who may have little formal training advanced math. To address persistent barrier, we provide a general accessible guide that covers basic, step-by-step process approach, understand, use theory work. We first give an overview why mathematical created, outline four specific ways both verbal motivate work, finally present practical tool kit for reading aspects theory. hope empowering embrace their work will help move field closer full integration

Language: Английский

---

Predator Ecology

Oxford University Press eBooks, Journal Year: 2021, Volume and Issue: unknown

Published: Sept. 15, 2021

Abstract Predator-prey interactions form an essential part of ecological communities, determining the flow energy from autotrophs to top predators. The rate predation is a key regulator that flow, and determined by functional response. Functional responses themselves are emergent phenomena – they reflect morphology, behavior, physiology both predator prey outcomes evolution source additional evolution. response thus concept connects many aspects biology behavioral ecology eco-evolutionary dynamics food webs, as result, integrative science predatory ecology. In this book, I provide synthesis research on responses, starting with basics. then break down into foraging components connect these traits behaviors species in webs. conclude contrary appearances, we know very little about work necessary for us understand how environmental change management will impact systems

Language: Английский

---

The rise of the Functional Response in invasion science: a systematic review

NeoBiota, Journal Year: 2023, Volume and Issue: 85, P. 43 - 79

Published: June 9, 2023

Predicting which non-native species will negatively impact biodiversity is a longstanding research priority. The Functional Response (FR; resource use in relation to availability) classical ecological concept that has been increasingly applied quantify, assess and compare impacts of species. Despite this recent growth, an overview applications knowledge gaps across relevant contexts currently lacking. We conducted systematic review using combination terms regarding FR invasion science synthesise scientific studies apply the approach field suggest new areas where it could have valuable applications. Trends publications about general were compared through Activity Index. Data extracted from papers reveal temporal, bibliographic, geographic trends, patterns study attributes such as type interaction habitat investigated, taxonomic groups used, context-dependencies assessed. In total, 120 included review. identified substantial unevenness reporting FRs science, despite rapidly growing number studies. To date, geographically skewed towards North America Europe, well predator-prey interactions freshwater habitats. Most focused on few invertebrates fishes. Species origin, life stage, environmental temperature complexity most frequently considered context-dependencies. conclude while thus far narrowly applied, broad potential application can be used test major hypotheses field.

Language: Английский

---

Systematic bias in studies of consumer functional responses

Ecology Letters, Journal Year: 2020, Volume and Issue: 24(3), P. 580 - 593

Published: Dec. 31, 2020

Abstract Functional responses are a cornerstone to our understanding of consumer–resource interactions, so how best describe them using models has been actively debated. Here we focus on the consumer dependence functional evidence systematic bias in statistical comparison functional‐response and estimation their parameters. Both forms universal nonlinear (irrespective dependence) rooted lack sufficient replication. Using large compilation published datasets, show that – due prevalence low sample size studies neither overall frequency by which alternative achieve top rank nor distribution parameter point estimates should be treated as providing insight into general form or central tendency interference. We call for renewed clarity varied purposes motivate study responses, can compete with each other dictating design, analysis interpretation experiments.

Language: Английский

---

Predicting effects of multiple interacting global change drivers across trophic levels

Global Change Biology, Journal Year: 2022, Volume and Issue: 29(5), P. 1223 - 1238

Published: Dec. 3, 2022

Global change encompasses many co-occurring anthropogenic drivers, which can act synergistically or antagonistically on ecological systems. Predicting how different global drivers simultaneously contribute to observed biodiversity is a key challenge for ecology and conservation. However, we lack the mechanistic understanding of multiple influence vital rates interacting species. We propose that reaction norms, relationships between driver like growth, mortality, consumption, provide insights underlying mechanisms community responses drivers. Understanding interact affect demographic using reaction-norm perspective improve our ability make predictions interactions at higher levels organization-that is, food web. Building framework consumer-resource widely studied thermal performance curves, illustrate joint impacts be scaled up from population level. A simple proof-of-concept model demonstrates norms predict prevalence literature search suggests proposed approach not yet used in research. outline realistic response surfaces (i.e., multidimensional norms) inferred by parametric nonparametric approaches. Response have potential strengthen communities as well when interactive effects emerge, two major challenges today.

Language: Английский

---

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

---

Asymmetrical effects of temperature on stage‐structured predator–prey interactions

Functional Ecology, Journal Year: 2021, Volume and Issue: 35(5), P. 1041 - 1054

Published: Feb. 24, 2021

Abstract Warming can impact consumer–resource interactions through multiple mechanisms. For example, warming both alter the rate at which predators consume prey and develop vulnerable life stages. Thus, overall effect of on will depend upon strength asymmetry effects predator performance. Here, we quantified temperature dependence (a) density‐dependent predation rates for two dragonfly nymph a shared mosquito larval prey, via functional response, (b) development to predator‐invulnerable adult stage. We united results these empirical studies using temperature‐ stage‐structured model predict number larvae that survive adulthood. accelerated increased consumption. Model simulations suggest differences in magnitude responses determined change survival Specifically, found depending species were exposed model, net was either an reduction or no across gradient. Our highlight need better mechanistic understanding differential pairs accurately how affects food web dynamics. A free plain language summary be within Supporting Information this article.

Language: Английский

---

Trait-Based Variation in the Foraging Performance of Individuals

Frontiers in Ecology and Evolution, Journal Year: 2021, Volume and Issue: 9

Published: June 17, 2021

Although average, species-level interaction strength plays a key role in driving population dynamics and community structure, predator-prey interactions occur among individuals. As result, individual variation foraging rates may play an important determining the effects of on communities. Such stems from traits that influence mechanistic components functional response, such as movements determine encounters behaviors decisions to attack. However, we still have little information about individual-level responses or give rise variation. Here combine standard response experiment with wolf spiders fruit flies novel analysis connect morphology, physiology, movement performance. We found substantial between males females, but these were not clearly linked differences females. Contrary expectations, no effect body velocity, leg length, energetic state, metabolic rate Instead, mass interacted rotations (clockwise turns), larger showed higher performance when they turned more reverse was true for smaller spiders. Our results highlight need understand apparent complexity links individuals response.

Language: Английский

---

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

---