scholarly journals Effect of delay and control on a predator–prey ecosystem with generalist predator and group defence in the prey species

2021 ◽  
Vol 137 (1) ◽  
Author(s):  
Rajesh Ranjan Patra ◽  
Soumen Kundu ◽  
Sarit Maitra
2019 ◽  
Vol 24 (5) ◽  
Author(s):  
Debabrata Das ◽  
Tapan Kumar Kar

This article examines the effectiveness of feedback control as a management policy on a generalist predator–prey system with prey harvesting. We discuss the result of implementing feedback control with respect to prey and predator separately. This paper also depicts the effect of exploitations up to maximum sustainable yield (MSY). We observe that with a constant fishing effort MSY policy is a sustainable management policy to protect both the species. However, further increase of fishing effort may cause the extinction of prey species. But considering feedback control of fishing effort may restrict the extinction of prey species. When fishing effort is controlled in terms of prey density, the extinction of prey population can be avoided. In this case, there may be coexistences of prey, predator and fishery or extinction of fishery. But when fishing effort is controlled by predator density, it is difficult to manage the coexistences of prey, predator and fishery.  


1995 ◽  
Vol 22 (1) ◽  
pp. 55 ◽  
Author(s):  
R. P. Pech ◽  
A. R. E. Sinclair ◽  
A. E. Newsome

In Australia, the red fox (Vulpes vulpes) is a generalist predator of European rabbits (Oryctolagus cuniculus) and a range of small to medium-sized native species. The available evidence suggests that foxes are capable of regulating rabbits in semi-arid environments but their role in the population dynamics of other prey species is not clear. A series of models, and associated experimental tests, that compare the effects of predation on primary and secondary prey species are described. The models are appropriate to the time scale of prey dynamics and differ from recent predator–prey models that focus on predator dynamics. These ideas are discussed for the fox and several of its prey species in Australia.


Author(s):  
Xavier Lambin

The dependency of mustelid demographic rates on prey abundance has the potential to cause a strong coupling between predator-prey populations. Data on mustelid dynamics show that such strong reciprocal interactions only materialise in some restricted conditions. Bite-size mustelid predators searching for scarce, depleted prey expose themselves to increased risk of predation by larger predators of small mammal that are themselves searching for similar prey species. As voles or muskrats become scarcer, weasels and mink searching for prey over larger areas become increasingly exposed to intra-guild predation, unless they operate in a habitat refuge such as the sub-nivean space. Where larger predators are sufficiently abundant or exert year-round predation pressure on small mustelids, their impact on mustelids may impose biological barrier to dispersal that are sufficient to weaken the coupling between small mustelids and their rodent prey, and thus impose a degree of top down limitation on mustelids.


Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 169
Author(s):  
Danai-Eleni Michailidou ◽  
Maria Lazarina ◽  
Stefanos P. Sgardelis

The ongoing climate change and the unprecedented rate of biodiversity loss render the need to accurately project future species distributional patterns more critical than ever. Mounting evidence suggests that not only abiotic factors, but also biotic interactions drive broad-scale distributional patterns. Here, we explored the effect of predator-prey interaction on the predator distribution, using as target species the widespread and generalist grass snake (Natrix natrix). We used ensemble Species Distribution Modeling (SDM) to build a model only with abiotic variables (abiotic model) and a biotic one including prey species richness. Then we projected the future grass snake distribution using a modest emission scenario assuming an unhindered and no dispersal scenario. The two models performed equally well, with temperature and prey species richness emerging as the top drivers of species distribution in the abiotic and biotic models, respectively. In the future, a severe range contraction is anticipated in the case of no dispersal, a likely possibility as reptiles are poor dispersers. If the species can disperse freely, an improbable scenario due to habitat loss and fragmentation, it will lose part of its contemporary distribution, but it will expand northwards.


1986 ◽  
Vol 64 (11) ◽  
pp. 2624-2633 ◽  
Author(s):  
Peter F. Major ◽  
Lawrence M. Dill ◽  
David M. Eaves

Three-dimensional interactions between grouped aerial predators (frontal discs of aircraft engines), either linearly arrayed or clustered, and flocks of small birds were studied using interactive computer simulation techniques. Each predator modelled was orders of magnitude larger than an individual prey, but the prey flock was larger than each predator. Expected numbers of individual prey captured from flocks were determined for various predator speeds and trajectories, flock–predator initial distances and angles, and flock sizes, shapes, densities, trajectories, and speeds. Generally, larger predators and clustered predators caught more prey. The simulation techniques employed in this study may also prove useful in studies of predator–prey interactions between schools or swarms of small aquatic prey species and their much larger vertebrate predators, such as mysticete cetaceans.The study also provides a method to study problems associated with turbine aircraft engine damage caused by the ingestion of small flocking birds, as well as net sampling of organisms in open aquatic environments.


2010 ◽  
Vol 2010 ◽  
pp. 1-12
Author(s):  
Xiangzeng Kong ◽  
Zhiqin Chen ◽  
Li Xu ◽  
Wensheng Yang

We propose and study the permanence of the following periodic Holling III predator-prey system with stage structure for prey and both two predators which consume immature prey. Sufficient and necessary conditions which guarantee the predator and the prey species to be permanent are obtained.


2008 ◽  
Vol 2008 ◽  
pp. 1-15 ◽  
Author(s):  
Can-Yun Huang ◽  
Min Zhao ◽  
Hai-Feng Huo

A stage-structured three-species predator-prey model with Beddington-DeAngelis and Holling II functional response is introduced. Based on the comparison theorem, sufficient and necessary conditions which guarantee the predator and the prey species to be permanent are obtained. An example is also presented to illustrate our main results.


2020 ◽  
Vol 28 (2) ◽  
pp. 155-179
Author(s):  
Nuno Onofre ◽  
Luís Sampaio

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.


2020 ◽  
Vol 134 (1) ◽  
pp. 45-51
Author(s):  
Juliana Balluffi-Fry ◽  
Liane B. Nowell ◽  
Murray M. Humphries

The feeding habits of generalist predators often vary among populations and regions. For example, Coyote (Canis latrans), which is a generalist predator distributed across North America, occupies a wide range of habitats and has a highly varied diet. In this observational study, we quantified the presence of mammalian prey items in 50 Eastern Coyote (Canis latrans var.) scats collected in late spring and summer in a private game reserve in southwestern Quebec. Nearly all scats contained hair of White-tailed Deer (Odocoileus virginianus; 44%), Moose (Alces americanus; 38%), or American Beaver (Castor canadensis; 38%). Although all three species are known to be consumed by coyotes, such a high proportion of Moose and White-tailed Deer simultaneously occurring in the diet of coyotes has not been previously reported. The uniqueness of the study area, with its relatively high abundance of all three prey species, may account for the uniqueness of the diet of Eastern Coyotes living there.


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