scholarly journals Beyond predator satiation: Masting but also the effects of rainfall stochasticity on weevils drive acorn predation

Ecosphere ◽  
2017 ◽  
Vol 8 (6) ◽  
pp. e01836 ◽  
Author(s):  
Josep Maria Espelta ◽  
Harold Arias-LeClaire ◽  
Marcos Fernández-Martínez ◽  
Enrique Doblas-Miranda ◽  
Alberto Muñoz ◽  
...  
2012 ◽  
Vol 9 (2) ◽  
pp. 220-228
Author(s):  
Baghdad Science Journal

This study evaluated the functional response of the larva of the predator Chrysoperla carnea by offering varying densities of cabbage aphid, Brevicoryne brassicae (L.) . Results showed conformity with type–II functional response, where the number of prey killed approaches asymptote hyperbolically as prey density increases (declining proportion of prey killed or the inverse density dependent) till it reached the stability stage determined by handling time and predator satiation. Also, the values of attack rate and handling time changed with age progress for both predator and prey. It has been observed an increase in the attack rate and reduction in handling time with the progress of the predator age when feeding on a particular nymphal instar. The attack rates of the predator was 1.779,3.406 and 4.219 ,while handling time was 0.015,0.010 and 0.008 (days) for 1st,2nd,3rd larval instars respectively, when fed on 1st nymphal instar. Also attack rates decreased and increases handling time with the progress in the prey. The attack rates were 1.779, 1.392, 1.096 and 1.059, due to an increase in size of the predator and in the growing efficiency in hunting the prey as well as in the increase in size of the prey and in developing its ability to defend itself and escape.


2016 ◽  
Vol 119 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Zhishu Xiao ◽  
Xiangcheng Mi ◽  
Marcel Holyoak ◽  
Wenhua Xie ◽  
Ke Cao ◽  
...  

2018 ◽  
Vol 28 (11) ◽  
pp. 2131-2159 ◽  
Author(s):  
Willian Cintra ◽  
Cristian Morales-Rodrigo ◽  
Antonio Suárez

In this paper, we study the existence and non-existence of coexistence states for a cross-diffusion system arising from a prey–predator model with a predator satiation term. We use mainly bifurcation methods and a priori bounds to obtain our results. This leads us to study the coexistence region and compare our results with the classical linear diffusion predator–prey model. Our results suggest that when there is no abundance of prey, the predator needs to be a good hunter to survive.


Ecology ◽  
2018 ◽  
Vol 99 (11) ◽  
pp. 2575-2582 ◽  
Author(s):  
Michał Bogdziewicz ◽  
Shealyn Marino ◽  
Raul Bonal ◽  
Rafał Zwolak ◽  
Michael A. Steele

1995 ◽  
Vol 22 (1) ◽  
pp. 89 ◽  
Author(s):  
S. Boutin

Fluctuating populations of small mammals provide an excellent opportunity to study the functional and numerical responses of predators because of the wide range in prey density that occurs. I reinterpret data from six studies that have examined the role of predation in the population dynamics of voles in California, southern Sweden and western Finland, of snowshoe hares in northern Canada, and of house mice and rabbits in Australia. Most studies have measured functional responses by relying on changes in diet as reflected by scat or stomach contents. These methods are probably biased toward showing predator satiation. Contrary to previous conclusions I find that there is little evidence for non-linear (Type 111) functional-response curves or predator satiation at high prey densities. Recent studies indicate that the functional and numerical responses of predators can be rapid and strong enough to initiate cyclic declines, dampen fluctuations, or even cause stable numbers. The exception to this appears to be the irruptions of mice and rabbits in Australia. I propose a general explanation for the role of predation whereby the effect of predation is largely dependent on the entire prey community. When potentially cyclic prey are a small component of the overall prey biomass, generalist predators are able to prevent fluctuations by strong functional or numerical responses. As the prey community becomes dominated by a few species that fluctuate, limit cycles predominate. Limit cycles turn into irruptive population dynamics when seasonal prey reproduction is eliminated because of extended periods of vegetation growth (vegetation flushes following drought). In the future we must test assumptions underlying the way we study predation by telemetric monitoring of prey mortality and by experimentally manipulating predation.


Sign in / Sign up

Export Citation Format

Share Document