Does altering patch number and connectivity change the predatory functional response type? Experiments and simulations in an acarine predator–prey system

2005 ◽  
Vol 83 (6) ◽  
pp. 797-806 ◽  
Author(s):  
P J Lester ◽  
J M Yee ◽  
S Yee ◽  
J Haywood ◽  
H MA Thistlewood ◽  
...  
Keyword(s):  
Functional Response ◽  
Panonychus Ulmi ◽  
Type Ii ◽  
Response Type ◽  
Predator Prey ◽  
Amblyseius Fallacis ◽  
Type Iii ◽  
Prey Interaction ◽  
Patch Connectivity

In multipatch landscapes, understanding the role of patch number and connectivity is key for the conservation of species under processes such as predation. The functional response is the most basic form of the predator–prey interaction. Two common response types exist: a decelerating curvilinear increase in prey consumption with prey density to a plateau (type II) and a sigmoidal-shaped curve (type III). Type II responses have been observed for a variety of predators, though only type III responses allow long-term persistence and are demographically stabilizing. We tested the hypothesis that the functional response type can change from a type II to a type III with increasing patch number and (or) decreasing connectivity. The predatory mite Amblyseius fallacis (Garman, 1948) has previously been shown to have a type II response when feeding on Panonychus ulmi (Koch, 1839). We examined this predator–prey interaction using experiments that varied in patch number, and simulations that varied in both patch number and connectivity. In no experimental or simulation trial did altering patch number or connectivity change the predator's functional response from type II to type III, even with an 80-fold decrease in patch connectivity. How do predators with this demographically destabilizing functional response persist? Hypotheses regarding metapopulations and alternative prey are discussed.

scholarly journals MODEL PREDATOR-PREY MENGGUNAKAN RESPON FUNGSIONAL TIPE II DENGAN PREY BERSIMBIOSIS MUTUALISME

2013 ◽  
Vol 5 (1) ◽  
pp. 35
Author(s):  
Ahmad Nasikhin ◽  
Niken Larasati
Keyword(s):  
Dynamic Behavior ◽  
Functional Response ◽  
Equilibrium Points ◽  
Type Ii ◽  
Response Type ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Symbiotic Mutualism ◽  
Model Predator

In this paper, we study the dynamic behavior of predator-prey model using functional response type II and symbiotic mutualism of prey. One of the six equilibrium points is the coexistence point which is asymtotically stable. In this point, the number of prey and predator for a long term depends on the interaction level of prey to another species and the interaction level of another species to prey.

scholarly journals Warming can destabilise predator-prey interactions by shifting the functional response from Type III to Type II

2018 ◽  
Author(s):  
Uriah Daugaard ◽  
Owen Petchey ◽  
Frank Pennekamp
Keyword(s):  
Population Dynamics ◽  
Functional Response ◽  
Conversion Efficiency ◽  
Trophic Interactions ◽  
Clearance Rate ◽  
Temperature Effects ◽  
Type Ii ◽  
Predator Prey ◽  
Type Iii ◽  
Population Dynamic Model

The potential for climate change and temperature shifts to affect community stability remains relatively unknown. One mechanism by which temperature may affect stability is by altering trophic interactions. The functional response quantifies the per capita resource consumption by the consumer as a function of resource abundance and is a suitable framework for the description of nonlinear trophic interactions. We studied the effect of temperature on a ciliate predator-prey pair (Spathidium sp. and Dexiostoma campylum) by estimating warming effects on the functional response and on the associated conversion efficiency of the predator. We recorded prey and predator dynamics over 24 hours and at three temperature levels (15, 20 and 25 C). To these data we fitted a population dynamic model including the predator functional response, such that the functional response parameters (space clearance rate, handling time, and density dependence of space clearance rate) were estimated for each temperature separately. To evaluate the ecological significance of temperature effects on the functional response parameters we simulated predator-prey population dynamics. We considered the predator-prey system to be destabilised, if the prey was driven extinct by the predator. Effects of increased temperature included a transition of the functional response from a Type III to a Type II and an increase of the conversion efficiency of the predator. The simulated population dynamics showed a destabilisation of the system with warming, with greater risk of prey extinction at higher temperatures likely caused by the transition from a Type III to a Type II functional response. Warming-induced shifts from a Type III to II are not commonly considered in modelling studies that investigate how population dynamics respond to warming. Future studies should investigate the mechanism and generality of the effect we observed and simulate temperature effects in complex food webs including shifts in the type of the functional response as well as consider the possibility of a temperature dependent conversion efficiency.

scholarly journals Warming can destabilize predator–prey interactions by shifting the functional response from Type III to Type II

2019 ◽  
Vol 88 (10) ◽  
pp. 1575-1586 ◽  
Author(s):  
Uriah Daugaard ◽  
Owen L. Petchey ◽  
Frank Pennekamp
Keyword(s):  
Functional Response ◽  
Type Ii ◽  
Predator Prey ◽  
Type Iii

scholarly journals Functional response of the predator Eriopis connexa (Coleoptera: Coccinellidae) to different prey types

2007 ◽  
Vol 50 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Renato Almeida Sarmento ◽  
Angelo Pallini ◽  
Madelaine Venzon ◽  
Og Francisco Fonseca de Souza ◽  
Adrián José Molina-Rugama ◽  
...  
Keyword(s):  
Functional Response ◽  
Biological Control Agent ◽  
Control Agent ◽  
Macrosiphum Euphorbiae ◽  
Type Ii ◽  
Response Type ◽  
Tetranychus Evansi ◽  
Type Iii ◽  
Eriopis Connexa ◽  
Type Ii Functional Response

This work evaluated the functional response of adult females of Eriopis connexa to different densities of Macrosiphum euphorbiae and Tetranychus evansi. When preying upon aphids, E. connexa presented a sigmoidal functional response (Type III). This behavior, however, changed drastically to an exponential (Type II) functional response, when mites (T. evansi), rather than aphids, were offered to E. connexa. Such different patterns showed that this coccinellid needed to adopt distinct strategies according to the kind of prey available. Since predators were believed to be able to regulate prey populations only when adopting Type III functional response. E. connexa would be a good candidate for a biological control agent of M. euphorbiae, but would not suppress a growing population of T. evansi.

A New Classification for Pathologies of Spinal Meninges, Part 1: Dural Cysts, Dissections, and Ectasias

Neurosurgery ◽  
2017 ◽  
Vol 81 (1) ◽  
pp. 29-44 ◽  
Author(s):  
Jörg Klekamp
Keyword(s):  
Structural Changes ◽  
Long Term Results ◽  
Type I ◽  
Type Ii ◽  
New Classification ◽  
Type Iii ◽  
Dural Sac ◽  
Spinal Cord Herniation ◽  
Dural Defects

Abstract BACKGROUND: The clinical significance of pathologies of the spinal dura is often unclear and their management controversial. OBJECTIVE: To classify spinal dural pathologies analogous to vascular aneurysms, present their symptoms and surgical results. METHODS: Among 1519 patients with spinal space-occupying lesions, 66 patients demonstrated dural pathologies. Neuroradiological and surgical features were reviewed and clinical data analyzed. RESULTS: Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery. CONCLUSION: The majority of dural pathologies involving root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Type I and type II pathologies were treated with good long-term results occluding their dural defects, while ectasias of the dural sac (type III) were managed conservatively.

BIFURCATION AND CHAOS IN A DISCRETE PREDATOR–PREY MODEL WITH HOLLING TYPE-III FUNCTIONAL RESPONSE AND HARVESTING EFFECT

2021 ◽  
pp. 1-28
Author(s):  
ANURAJ SINGH ◽  
PREETI DEOLIA
Keyword(s):  
Functional Response ◽  
Sufficient Conditions ◽  
Flip Bifurcation ◽  
Bifurcation Structure ◽  
Bifurcation And Chaos ◽  
Predator Prey ◽  
Type Iii ◽  
Predator Prey Model ◽  
Prey Model ◽  
Wide Range

In this paper, we study a discrete-time predator–prey model with Holling type-III functional response and harvesting in both species. A detailed bifurcation analysis, depending on some parameter, reveals a rich bifurcation structure, including transcritical bifurcation, flip bifurcation and Neimark–Sacker bifurcation. However, some sufficient conditions to guarantee the global asymptotic stability of the trivial fixed point and unique positive fixed points are also given. The existence of chaos in the sense of Li–Yorke has been established for the discrete system. The extensive numerical simulations are given to support the analytical findings. The system exhibits flip bifurcation and Neimark–Sacker bifurcation followed by wide range of dense chaos. Further, the chaos occurred in the system can be controlled by choosing suitable value of prey harvesting.

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