Functional Responses Shape Node and Network Level Properties of a Simplified Boreal Food Web

Gobin, Jenilee; Hossie, Thomas J.; Derbyshire, Rachael; Sonnega, Samuel; Cambridge, Tucker W.; Scholl, Lee; Kloch, Nicolas Diaz; Scully, Arthur; Thalen, Kiefer; Smith, Graeme; Scott, Carly; Quinby, Francis; Reynolds, Jordan N. H.; Miller, Hannah A.; Faithfull, Holly; Lucas, O.; Dennison, Christopher; McDonald, Jordan; Boutin, Stan; O’Donoghue, Mark; Boonstra, Rudy; Murray, Dennis L.

doi:10.3389/fevo.2022.898805

Cited by 7 publications

(10 citation statements)

References 99 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Researchers use functional responses to quantitatively describe the interactions of consumers and resources, including, but not limited to, predator-prey, parasitoid-host, parasitehost, or filter-feeder-plankton interactions. The functional response concept (Solomon, 1949;Holling, 1959a,b) is a cornerstone of population and food-web ecology and is still widely relevant (e.g., DeLong, 2021;Gobin et al, 2022). Solomon (1949) introduced the idea by stating: "…there must be a functional response to (say) an increase in the host density, because of the increased availability of victims: as host density rises, each enemy will attack more host individuals,…".…”

Section: Introduction 1what Are Functional Responses?mentioning

confidence: 99%

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

et al. 2023

View full text Add to dashboard Cite

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

show abstract

Section: Introduction 1what Are Functional Responses?mentioning

confidence: 99%

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

et al. 2023

View full text Add to dashboard Cite

show abstract

“…In this paper, we use three basic forms of the functional response as simple heuristics for conservation managers: linear (called a Type I), asymptotic or saturating (Type II), and sigmoidal (Type III) where a predator's food intake increases slowly at first and then asymptotes (see Figure 2.1 in DeLong, 2021). The ecology of functional responses is far more complex than these simple depictions given the influence of factors other than the density of the focal prey, such as the density of alternative prey, food caching, surplus killing, diet switching and predator interference (e.g., Abrams, 2022; DeLong, 2021; Gobin et al, 2022; Krebs, 2022). These complexities are not considered here.…”

Section: A Precis Of Numerical and Functional Responses And Prey Recr...mentioning

confidence: 99%

Total response models as a conceptual management framework for conserving vulnerable secondary prey

Norbury

Reardon²

2023

Conservat Sci and Prac

View full text Add to dashboard Cite

Many of the world's native fauna suffer unsustainable losses from invasive mammalian predators. Conservation managers control predators on the premise that if large numbers are removed, prey will respond. This is sometimes true, but not always. Empirical relationships between predator densities and responses of vulnerable prey in Oceania often show little or no response across a broad range of predator reductions, with positive responses only at low threshold predator densities. Even then, some prey populations fail to respond.More research is required to identify predator thresholds across a range of prey taxa. This uncertainty of outcomes, coupled with the considerable cost of mammalian pest control, risks little or no return from limited conservation funds. A unifying theory is required to help understand why conservation outcomes from predator control are so variable despite the best efforts of conservation managers, and to expedite the right kind of management for a given prey species. We argue that a modern synthesis of numerical and functional response theory, in the form of total response models, provides such a theory. Stochastic consumer-resource models are recommended for dynamic systems, but they are difficult to parameterize. Total response models, on the other hand, present a simple conceptual framework that managers can use as a heuristic to understand predator-prey systems, help explain some of the variability in predator control outcomes and stimulate thinking about other management options that can be integrated with predator control to improve conservation outcomes. Five rules of thumb are suggested to assist conservation managers.

show abstract

“…Recent empirical work has suggested that a variety of different interference effects occur between different mammalian top predators (Engebretsen et al, 2021). Gobin et al (2022) discuss several modifications of type II responses in the context of models of a relatively well-studied boreal system in which five vertebrate species were represented. They analyze food web properties of best-fit models with different functional response forms, and conclude that type II responses produce relative poor fits to observed population and food web data.…”

Section: Adaptively Flexible Functional Responses In Models With Threementioning

confidence: 99%

Food web functional responses

Abrams

2022

Front. Ecol. Evol.

View full text Add to dashboard Cite

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

show abstract

Functional Responses Shape Node and Network Level Properties of a Simplified Boreal Food Web

Cited by 7 publications

References 99 publications

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

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

Total response models as a conceptual management framework for conserving vulnerable secondary prey

Food web functional responses

Contact Info

Product

Resources

About