scholarly journals Building a mechanistic understanding of predation with GPS-based movement data

2010 ◽  
Vol 365 (1550) ◽  
pp. 2279-2288 ◽  
Author(s):  
Evelyn Merrill ◽  
Håkan Sand ◽  
Barbara Zimmermann ◽  
Heather McPhee ◽  
Nathan Webb ◽  
...  
Keyword(s):  
Functional Response ◽  
Handling Time ◽  
Response Models ◽  
Movement Data ◽  
Global Positioning ◽  
Important Challenge ◽  
Sources Of Variation ◽  
Functional Response Models ◽  
Kill Site ◽  
The Right

Quantifying kill rates and sources of variation in kill rates remains an important challenge in linking predators to their prey. We address current approaches to using global positioning system (GPS)-based movement data for quantifying key predation components of large carnivores. We review approaches to identify kill sites from GPS movement data as a means to estimate kill rates and address advantages of using GPS-based data over past approaches. Despite considerable progress, modelling the probability that a cluster of GPS points is a kill site is no substitute for field visits, but can guide our field efforts. Once kill sites are identified, time spent at a kill site (handling time) and time between kills (killing time) can be determined. We show how statistical models can be used to investigate the influence of factors such as animal characteristics (e.g. age, sex, group size) and landscape features on either handling time or killing efficiency. If we know the prey densities along paths to a kill, we can quantify the ‘attack success’ parameter in functional response models directly. Problems remain in incorporating the behavioural complexity derived from GPS movement paths into functional response models, particularly in multi-prey systems, but we believe that exploring the details of GPS movement data has put us on the right path.

THE FUNCTIONAL RESPONSE AND PREY PREFERENCE OF FELTIELLA ACARISUGA (VALLOT) (DIPTERA: CECIDOMYIIDAE) FOR TWO OF ITS PREY: MALE AND FEMALE TWOSPOTTED SPIDER MITES, TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIIDAE)

1997 ◽  
Vol 129 (2) ◽  
pp. 221-227 ◽  
Author(s):  
G.P. Opit ◽  
B. Roitberg ◽  
D.R. Gillespie
Keyword(s):  
Functional Response ◽  
Tetranychus Urticae ◽  
Handling Time ◽  
Response Models ◽  
Male And Female ◽  
Functional Response Models ◽  
Prey Handling ◽  
Tetranychus Urticae Koch ◽  
Type Ii Functional Response ◽  
Twospotted Spider

AbstractThe preference of the predatory midge, Feltiella acarisuga (Vallot), for adult male and female twospotted spider mite, Tetranychus urticae Koch, was examined using functional response models. The midge exhibited a type-II functional response to each prey. Handling time was estimated to be much higher for the female mites than for the males (1.52 vs. 0.40 h). Estimated instantaneous search rates for the female and male mites were similar (1.32 vs. 1.28). A preference index of 1.03 was calculated using the ratio of the instantaneous search rates. Feltiella acarisuga was found to exhibit no preference for either female or male mites; when both prey were present in equal numbers, midge larvae killed as many females as males.

A COMPARISON OF TWO MODELS OF THE FUNCTIONAL RESPONSE WITH EMPHASIS ON PARAMETER ESTIMATION PROCEDURES

1970 ◽  
Vol 102 (9) ◽  
pp. 1094-1101 ◽  
Author(s):  
Norman R. Glass
Keyword(s):  
Parameter Estimation ◽  
Least Squares ◽  
Functional Response ◽  
Handling Time ◽  
Logistic Function ◽  
Model Fit ◽  
Response Models ◽  
Nonlinear Functional ◽  
Functional Response Models ◽  
Parameter Values

AbstractThe two primary functional response models extant in recent entomological literature were compared using a common set of data. Use of an iterative least squares parameter estimation routine was shown to be essential to a comparison of these two models. With parameters properly determined, the Watt model fit data on one out of five experiment days best, the Holling model fit data best on four out of five experiment days. The "handling time" submodel was shown to require iterative least squares parameter estimation rather than the usual log transformation and subsequent fitting of this logistic function by standard linear regression techniques. The conclusion was reached that if accuracy in prediction by nonlinear functional response models is desired, proper methods of determining parameter values are of critical importance.

PREFERENCE OF REDUVIOLUS AMERICOFERUS (HEMIPTERA: NABIDAE) FOR POTATO LEAFHOPPER NYMPHS AND PEA APHIDS

1985 ◽  
Vol 117 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
P.W. Flinn ◽  
A.A. Hower ◽  
R.A.J. Taylor
Keyword(s):  
Functional Response ◽  
Acyrthosiphon Pisum ◽  
Handling Time ◽  
Potato Leafhopper ◽  
Response Models ◽  
Preference Index ◽  
Pea Aphids ◽  
Functional Response Models ◽  
Prey Handling ◽  
Type Ii Functional Response

AbstractThe preference of the nabid, Reduviolus americoferus (L.), for potato leafhopper nymphs, Empoasca fabae (Harris), and pea aphids, Acyrthosiphon pisum (Harris), was examined using functional response models. The nabid exhibited a type-II functional response to each prey. Handling time was much higher for the aphid than for the leafhopper (3.623 vs. 0.211 h). Instantaneous search rates were also higher for the aphid (0.096 vs. 0.020 h−1). A preference index was calculated using the ratio of the instantaneous search rates. The nabid exhibited strong preference for the aphid; when both prey were present in equal numbers, the nabid consumed 3 times as many aphids. The predator did not switch to leafhopper nymphs as the proportion of leafhoppers was increased.

scholarly journals Space race functional responses

2015 ◽  
Vol 282 (1801) ◽  
pp. 20142121 ◽  
Author(s):  
Henrik Sjödin ◽  
Åke Brännström ◽  
Göran Englund
Keyword(s):  
Functional Response ◽  
Community Dynamics ◽  
Simple Structure ◽  
Functional Responses ◽  
Response Models ◽  
Predator Prey ◽  
Prey System ◽  
Space Race ◽  
Functional Response Models ◽  
The Relationship

We derive functional responses under the assumption that predators and prey are engaged in a space race in which prey avoid patches with many predators and predators avoid patches with few or no prey. The resulting functional response models have a simple structure and include functions describing how the emigration of prey and predators depend on interspecific densities. As such, they provide a link between dispersal behaviours and community dynamics. The derived functional response is general but is here modelled in accordance with empirically documented emigration responses. We find that the prey emigration response to predators has stabilizing effects similar to that of the DeAngelis–Beddington functional response, and that the predator emigration response to prey has destabilizing effects similar to that of the Holling type II response. A stability criterion describing the net effect of the two emigration responses on a Lotka–Volterra predator–prey system is presented. The winner of the space race (i.e. whether predators or prey are favoured) is determined by the relationship between the slopes of the species' emigration responses. It is predicted that predators win the space race in poor habitats, where predator and prey densities are low, and that prey are more successful in richer habitats.

Predicting Predation through Prey Ontogeny Using Size-Dependent Functional Response Models

2011 ◽  
Vol 177 (6) ◽  
pp. 752-766 ◽  
Author(s):  
Michael W. McCoy ◽  
Benjamin M. Bolker ◽  
Karen M. Warkentin ◽  
James R. Vonesh
Keyword(s):  
Functional Response ◽  
Response Models ◽  
Size Dependent ◽  
Functional Response Models

Evaluation of alternative prey-, predator-, and ratio-dependent functional response models in a zooplankton microcosm

2017 ◽  
Vol 95 (3) ◽  
pp. 177-182 ◽  
Author(s):  
Christina M. Prokopenko ◽  
Katrine Turgeon ◽  
John M. Fryxell
Keyword(s):  
Functional Response ◽  
Theoretic Approach ◽  
Type Ii ◽  
Predator Density ◽  
Response Models ◽  
Predator Interference ◽  
Kill Rate ◽  
Ratio Dependent ◽  
Functional Response Models ◽  
Rotifer Brachionus Calyciflorus

There is strenuous debate among ecologists regarding the inclusion of predator density into the originally prey-dependent functional response. We provided comprehensive empirical comparisons of alternative functional response models for the predatory ostracod Heterocypris incongruens (Ramdohr, 1808) and the rotifer Brachionus calyciflorus (Pallas, 1766) as its prey in small freshwater microcosms. Prey killed was measured at factorial combinations of four predator densities and five prey densities, and was recorded at 3 min intervals over 60 min experiments. To support the potential effect of predator interference on per capita kill rate, we recorded ostracod activity and aggression. Kill rate increased following a saturating function with increasing prey density and decreased with increasing predator density. Model evaluation using an information–theoretic approach indicated that the Arditi–Ginzburg type II ratio-dependent model performed best, followed by the Arditi–Akcakaya and Beddington–DeAngelis type II predator-dependent models, suggesting that predator interference was important in predicting kill rates. Interference among predators increased and their activity decreased with increasing predator density, providing confirmation that interference was responsible for the predator-dependent effect. By combining a microcosm experiment and behavioral observations, our results suggest that predator interference at realistic population densities influences ostracod kill rates and this form of interference was best accommodated by predator-dependent models.

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