نتایج جستجو برای: prey density

تعداد نتایج: 428600  

2018
R Keating Godfrey Ellen H Yerger Timothy J Nuttle

Overbrowsing by ungulates decimates plant populations and reduces diversity in a variety of ecosystems, but the mechanisms by which changes to plant community composition influence other trophic levels are poorly understood. In addition to removal of avian nesting habitat, browsing is hypothesized to reduce bird density and diversity through reduction of insect prey on browse-tolerant hosts lef...

Journal: :Physics of Plasmas 2022

In this work, the time-dependent solution for Lotka-Volterra Predator-Prey model is derived with help of Lambert W function. This allows an exact analytical expression period associated limit-cycle oscillations (LCO), and also response time between predator prey population. These results are applied to predator-prey interaction zonal density corrugations turbulent particle flux in gyrokinetic s...

Journal: :Proceedings. Biological sciences 2014
John L Orrock Robert J Fletcher

Anti-predator behaviour affects prey population dynamics, mediates cascading effects in food webs and influences the likelihood of rapid extinctions. Predator manipulations in natural settings provide a rare opportunity to understand how prey anti-predator behaviour is affected by large-scale changes in predators. Here, we couple a long-term, island-wide manipulation of an important rodent pred...

2018
Susana Rostro-García Jan F Kamler Rachel Crouthers Keo Sopheak Sovanna Prum Visattha In Chanratana Pin Anthony Caragiulo David W Macdonald

We studied the Indochinese leopard (Panthera pardus delacouri) in eastern Cambodia, in one of the few potentially remaining viable populations in Southeast Asia. The aims were to determine the: (i) current leopard density in Srepok Wildlife Sanctuary (SWS) and (ii) diet, prey selection and predation impact of leopard in SWS. The density, estimated using spatially explicit capture-recapture mode...

Journal: :Journal of theoretical biology 2009
Pierre Auger Rachid McHich Tanmay Chowdhury Gauthier Sallet Maurice Tchuente Joydev Chattopadhyay

We study the effects of a disease affecting a predator on the dynamics of a predator-prey system. We couple an SIRS model applied to the predator population, to a Lotka-Volterra model. The SIRS model describes the spread of the disease in a predator population subdivided into susceptible, infected and removed individuals. The Lotka-Volterra model describes the predator-prey interactions. We con...

Journal: :Ecology 2007
Kevin L Pangle Scott D Peacor Ora E Johannsson

We conducted a study to determine the contribution of lethal and nonlethal effects to a predator's net effect on a prey's population growth rate in a natural setting. We focused on the effects of an invasive invertebrate predator, Bythotrephes longimanus, on zooplankton prey populations in Lakes Michigan and Erie. Field data taken at multiple dates and locations in both systems indicated that t...

Journal: :Journal of Applied Mathematics and Computing 2021

Abstract Density dependent prey–predator systems under the impact of harvest are considered. The recruitment functions for both prey and predator belong to Deriso–Schnute family which allow us study how dynamical behaviour populations changes when compensatory density dependence turns overcompensatory. Depending on degree overcompensation, we show in case no that an increase fecundity always ac...

2016
Erica M. Holdridge Catalina Cuellar‐Gempeler Casey P. terHorst

Intraspecific competition influences population and community dynamics and occurs via two mechanisms. Exploitative competition is an indirect effect that occurs through use of a shared resource and depends on resource availability. Interference competition occurs by obstructing access to a resource and may not depend on resource availability. Our study tested whether the strength of interferenc...

Journal: :Journal of vector ecology : journal of the Society for Vector Ecology 2005
Karen J Willems Cameron E Webb Richard C Russell

Using larval Cx. annulirostris mosquitoes, this study compared the predation rate of Pseudomugil signifer and Gambusia holbrooki for four larval instars, three prey densities, and three vegetation densities. There was no significant difference in the quantity of first, second, and third instar larvae consumed by the two fish species after 24 h. There was a significant negative relationship betw...

2011
Gregor Kalinkat Björn Christian Rall Olivera Vucic-Pestic Ulrich Brose

The distribution of weak and strong non-linear feeding interactions (i.e., functional responses) across the links of complex food webs is critically important for their stability. While empirical advances have unravelled constraints on single-prey functional responses, their validity in the context of complex food webs where most predators have multiple prey remain uncertain. In this study, we ...

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