scholarly journals Ratio-dependent functional responses - tests with the zooplanktivore Mysis mixta

2001 ◽  
Vol 216 ◽  
pp. 181-189 ◽  
Author(s):  
S Hansson ◽  
BT De Stasio ◽  
E Gorokhova ◽  
MA Mohammadian
Keyword(s):  
Functional Responses ◽  
Mysis Mixta ◽  
Ratio Dependent

scholarly journals Quantifying predator dependence in the functional response of generalist predators

2016 ◽  
Author(s):  
Mark Novak ◽  
Christopher Wolf ◽  
Kyle Coblentz ◽  
Isaac Shepard
Keyword(s):  
Method Development ◽  
Field Experiments ◽  
Empirical Evaluation ◽  
Generalist Predators ◽  
Functional Responses ◽  
Predator Species ◽  
Ratio Dependence ◽  
Species Abundances ◽  
Ratio Dependent ◽  
Predator Dependence

AbstractA longstanding debate concerns whether functional responses are best described by prey-dependent versus ratio-dependent models. Theory suggests that ratio dependence can explain many food web patterns left unexplained by simple prey-dependent models. However, for logistical reasons, ratio dependence and predator dependence more generally have seen infrequent empirical evaluation and then only so in specialist predators, which are rare in nature. Here we develop an approach to simultaneously estimate the prey-specific attack rates and predator-specific interference rates of predators interacting with arbitrary numbers of prey and predator species. We apply the approach to field surveys and two field experiments involving two intertidal whelks and their full suite of potential prey. Our study provides strong evidence for the presence of weak predator dependence that is closer to being prey dependent than ratio dependent over manipulated and natural ranges of species abundances. It also indicates how, for generalist predators, even the qualitative nature of predator dependence can be prey-specific.Author contributionsCW contributed to method development, KC and IS performed the caging experiment, and MN conceived of the study, carried out the fieldwork and analyses, and wrote the manuscript.

scholarly journals Dynamics in a ratio-dependent Lotka–Volterra competitive-competitive-cooperative system with feedback controls and delays

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Ahmadjan Muhammadhaji ◽  
Azhar Halik ◽  
Hong-Li Li
Keyword(s):  
Time Delays ◽  
Dynamical Behavior ◽  
Sufficient Conditions ◽  
Comparison Method ◽  
Cooperative System ◽  
Functional Responses ◽  
Feedback Controls ◽  
Lyapunov Function Method ◽  
Inequality Techniques ◽  
Ratio Dependent

AbstractThis study investigates the dynamical behavior of a ratio-dependent Lotka–Volterra competitive-competitive-cooperative system with feedback controls and delays. Compared with previous studies, both ratio-dependent functional responses and time delays are considered. By employing the comparison method, the Lyapunov function method, and useful inequality techniques, some sufficient conditions on the permanence, periodic solution, and global attractivity for the considered system are derived. Finally, a numerical example is also presented to validate the practicability and feasibility of our proposed results.

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