نتایج جستجو برای: predation rate

تعداد نتایج: 971157  

2017
Callum Duffield Christos C Ioannou

Marginal predation, also known as the edge effect, occurs when aggregations of prey are preferentially targeted on their periphery by predators and has long been established in many taxa. Two main processes have been used to explain this phenomenon, the confusion effect and the encounter rate between predators and prey group edges. However, it is unknown at what size a prey group needs to be be...

Journal: :Biology letters 2013
Cameron K Ghalambor Susana I Peluc Thomas E Martin

Predation can be an important agent of natural selection shaping parental care behaviours, and can also favour behavioural plasticity. Parent birds often decrease the rate that they visit the nest to provision offspring when perceived risk is high. Yet, the plasticity of such responses may differ among species as a function of either their relative risk of predation, or the mean rate of provisi...

2015
Olga P. Dubovskaya Kam W. Tang Michail I. Gladyshev Georgiy Kirillin Zhanna Buseva Peter Kasprzak Aleksandr P. Tolomeev Hans-Peter Grossart Syuhei Ban

BACKGROUND Mortality is a main driver in zooplankton population biology but it is poorly constrained in models that describe zooplankton population dynamics, food web interactions and nutrient dynamics. Mortality due to non-predation factors is often ignored even though anecdotal evidence of non-predation mass mortality of zooplankton has been reported repeatedly. One way to estimate non-predat...

2015
Henrik Andrén Olof Liberg

The effects of predation on ungulate populations depend on several factors. One of the most important factors is the proportion of predation that is additive or compensatory respectively to other mortality in the prey, i.e., the relative effect of top-down and bottom-up processes. We estimated Eurasian lynx (Lynx lynx) kill rate on roe deer (Capreolus capreolus) using radio-collared lynx. Kill ...

2006
M. Falconi

In this paper, we are concerned with the role of the age structure of a prey in the dynamic of a predator prey model. Specifically, we study the effect of predation on a non-reproductive class of the prey, when the reproductive class of the prey presents a group defense mechanism. Three different scenarios are analyzed: (1) Constant predation rate on the nonreproductive class, no defense mechan...

Journal: :Proceedings. Biological sciences 2012
Nicholas J DeCesare

Predation risk is an important driver of ecosystems, and local spatial variation in risk can have population-level consequences by affecting multiple components of the predation process. I use resource selection and proportional hazard time-to-event modelling to assess the spatial drivers of two key components of risk--the search rate (i.e. aggregative response) and predation efficiency rate (i...

2003
Janne Sundell Jana A. Eccard Raisa Tiilikainen Hannu Ylönen

We studied the predation rate and prey selection of the least weasel (Mustela ni alis ni alis) on its two most common prey species in boreal environments, the bank vole (Clethrionomys glareolus) and the field vole (Microtus agrestis), in large outdoor enclosures. We also studied the response of weasels to odours of the two species in the laboratory. The enclosure experiment was conducted using ...

Journal: :Mathematical biosciences 2010
Souvik Bhattacharya Maia Martcheva

This article introduces a predator-prey model with the prey structured by body size, based on reports in the literature that predation rates are prey-size specific. The model is built on the foundation of the one-species physiologically structured models studied earlier. Three types of equilibria are found: extinction, multiple prey-only equilibria and possibly multiple predator-prey coexistenc...

2003
CATHRYN H. GREENBERG C. REED ROSSELL DAVID B. JOHNSON

Alxtruct: Predation rates were compared during three 7-day trials on 742 artificial ground nests located in 10 hurricane-created canopy gaps and IO adjacent closed-canopy controls in the southern Appalachian mountains of North Carolina. White northern bobwhite (Cdinus virginianus) eggs were used in trials 1 and 2, but brown-speckled Japanese Quail (Coturnix coturr~ix) eggs were used in trial 3 ...

ژورنال: علوم آب و خاک 2000
حاتمی, بیژن , زیبایی, کریم ,

The interference of biological agents may cause behaviors such as interspecific predation, reducing their efficiencies. The interspecific predation of lacewing, Chrysoperla carnea (Steph.) and ladybeetle, Hippodamia variegata (Goeze) was investigated in the presence and absence of prey, Aphis gossypii Glover under laboratory conditions. In the presence and absence of prey, the larvae of lacew...

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