scholarly journals Nonconsumptive predator effects on prey demography: Dogwhelk cues decrease benthic mussel recruitment

2017 ◽  
Author(s):  
Sonja M. Ehlers ◽  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Natural History ◽  
Prey Item ◽  
Experimental Conditions ◽  
Nonconsumptive Effects ◽  
Predator Prey ◽  
Prey System ◽  
Intertidal Habitats ◽  
Basic Features ◽  
The Impact ◽  
Predator Effects

AbstractPredators have often been shown to have nonconsumptive effects (NCEs) on prey behaviour, but the demographic consequences for prey remain poorly known. This is important to understand because demography influences the impact of a species in its community. We used an intertidal predator–prey system to investigate predator NCEs on prey recruitment, a key demographic process for population persistence. Pelagic mussel larvae are known to avoid waterborne cues from dogwhelks, which prey on intertidal mussels. Through a field experiment done in Atlantic Canada, we manipulated the presence of dogwhelks in intertidal habitats during the mussel recruitment season. We measured mussel recruitment in collectors that could be reached by waterborne dogwhelk cues but not by dogwhelks themselves. We found that the nearby presence of dogwhelks significantly decreased mussel recruit density. A previous study done in the same habitats under the same experimental conditions showed that dogwhelk cues also limit the recruitment of barnacles, another prey item for dogwhelks. However, such NCEs were four times stronger than those observed for mussel recruitment. This difference relates well to the higher ability of mussels to escape predation, as mussels can relocate while barnacles cannot. Therefore, basic features of natural history may be useful to predict predator NCEs on prey recruitment.

scholarly journals The role of sensory modalities in producing nonconsumptive effects for a crayfish–bass predator–prey system

2018 ◽  
Vol 96 (7) ◽  
pp. 680-691 ◽  
Author(s):  
Jessica L. Clark ◽  
Paul A. Moore
Keyword(s):  
Micropterus Salmoides ◽  
Interactive Effects ◽  
Predator Detection ◽  
Nonconsumptive Effects ◽  
Predator Prey ◽  
Rusty Crayfish ◽  
Sensory Modalities ◽  
Study Support ◽  
The Impact

The impact of nonconsumptive effects (NCEs) in structuring predator–prey interactions and trophic cascades is a prominent area of ecological research. For NCEs to occur, prey need to be able to detect the presence of predators through sensory mechanisms. The investigation of the role of different sensory modalities in predator detection has lagged behind the development of NCE-based theories. This study aimed to determine whether a hierarchy in the reliance upon sensory modalities exists in the rusty crayfish (Orconectes rusticus (Girard, 1852) = Faxonius rusticus (Girard, 1852)) for predator detection and if this hierarchy is altered across different sensory environments (flowing and nonflowing environments). Rusty crayfish were exposed to largemouth bass (Micropterus salmoides (Lacépède, 1802)) odor in either a flowing or nonflowing arena where behavior was recorded under different sensory lesions. Linear mixed models were conducted to determine the impact of lesions, flowing environments, and the interactive effects of lesions and flowing environments on the rusty crayfish ability to respond to predatory stimuli. Results from this study support the significance of sensory multimodality in the rusty crayfish for accurately detecting and assessing predatory threats. Results from this study also suggest a hierarchy in the reliance upon sensory modalities in the rusty crayfish that is dependent upon the environment and the location of rusty crayfish within an environment.

scholarly journals Transmission Dynamics of Resistant Bacteria in a Predator-Prey System

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
Xubin Gao ◽  
Qiuhui Pan ◽  
Mingfeng He
Keyword(s):  
Human Health ◽  
Large Scale ◽  
Equilibrium Points ◽  
Predation Rate ◽  
Resistant Bacteria ◽  
Mathematical Methods ◽  
Predator Prey ◽  
Prey System ◽  
The Stability ◽  
The Impact

This paper discusses the impact on human health caused by the addition of antibiotics in the feed of food animals. We use the established transmission rule of resistant bacteria and combine it with a predator-prey system to determine a differential equations model. The equations have three steady equilibrium points corresponding to three population dynamics states under the influence of resistant bacteria. In order to quantitatively analyze the stability of the equilibrium points, we focused on the basic reproduction numbers. Then, both the local and global stability of the equilibrium points were quantitatively analyzed by using essential mathematical methods. Numerical results are provided to relate our model properties to some interesting biological cases. Finally, we discuss the effect of the two main parameters of the model, the proportion of antibiotics added to feed and the predation rate, and estimate the human health impacts related to the amount of feed antibiotics used. We further propose an approach for the prevention of the large-scale spread of resistant bacteria and illustrate the necessity of controlling the amount of in-feed antibiotics used.

scholarly journals Dynamical Analysis of a Beddington–DeAngelis Interacting Species System with Prey Harvesting

2020 ◽  
Vol 2020 ◽  
pp. 1-22
Author(s):  
Lakshmi Narayan Guin ◽  
Reeta Murmu ◽  
Hunki Baek ◽  
Kyoung-Hwan Kim
Keyword(s):  
Equilibrium Point ◽  
Functional Response ◽  
Reaction Diffusion ◽  
Complete Analysis ◽  
Generalist Predator ◽  
Predator Prey ◽  
Interacting Species ◽  
Prey System ◽  
Persistence Property ◽  
The Impact

A reaction–diffusion interacting species system with Beddington–DeAngelis functional response that has been proposed in the environment of mathematical ecology, which provides the rise to spatial pattern formation, is investigated and associated with the models of deterministic dynamics. The dynamical behaviour of a generalist predator–prey system with linear harvesting of each species and predator-dependent functional response is fully analyzed. Conditions of stability behaviour of the interior equilibrium point are established properly. Furthermore, we have recognized that the unique positive equilibrium point of the system is globally stable via appropriate Lyapunov function structure, which signifies that appropriate harvesting has no impact on the persistence property of the harvesting system. Also, we establish the conditions for the existence of bifurcation phenomena including a saddle-node bifurcation and a Hopf bifurcation. Subsequently, complete analysis regarding the impact of harvesting is carried out, and an interesting decision is that under some appropriate constraints, harvesting has immense impact on the final size of the interacting species. In addition, in accordance with Turing’s ideas on morphogenesis , our analysis shows that harvesting effort in a reaction–diffusion predator–prey system plays a vital function for geological conservation of interacting species. Finally, we discuss sufficient conditions for the existence of bionomic equilibrium point and the optimal harvesting policy attained by using the Pontryagin maximal principle.

Hunting Cooperation in a Discrete-Time Predator–Prey System

2018 ◽  
Vol 28 (07) ◽  
pp. 1850083 ◽  
Author(s):  
Saheb Pal ◽  
Nikhil Pal ◽  
Joydev Chattopadhyay
Keyword(s):  
Numerical Simulations ◽  
Discrete Time ◽  
Period Doubling ◽  
Phase Portraits ◽  
Predator Population ◽  
Predator Prey ◽  
Prey System ◽  
Cooperation Rate ◽  
Route To Chaos ◽  
The Impact

The present paper mainly investigates the impact of hunting cooperation in a discrete-time predator–prey system through numerical simulations. We show that without hunting cooperation, an increase in the growth rate of prey population produces chaotic dynamics. We also show that hunting cooperation has the potential to modify the well-known period-doubling route to chaos by reverse period-halving bifurcations and makes the system stable. However, very high hunting cooperation can be detrimental and populations go to extinction. We observe that hunting cooperation induces strong demographic Allee effect in the system, where predator population persists due to hunting cooperation and would go to extinction without hunting cooperation. We perform extensive numerical simulations of the system and draw phase portraits, bifurcation diagrams, maximum Lyapunov exponents, two-parameter stability regions. We also observe the occurrence of flip and Neimark–Sacker bifurcations by taking the hunting cooperation rate as a bifurcation parameter.

Impact of Prey Refuge on a Discrete Time Predator–Prey System with Allee Effect

2014 ◽  
Vol 24 (09) ◽  
pp. 1450106 ◽  
Author(s):  
Sourav Rana ◽  
Amiya Ranjan Bhowmick ◽  
Sabyasachi Bhattacharya
Keyword(s):  
Discrete Time ◽  
Allee Effect ◽  
Chaotic Behavior ◽  
Large Fraction ◽  
Chaotic Oscillation ◽  
Prey Refuge ◽  
Predator Prey ◽  
Prey System ◽  
The Stability ◽  
The Impact

We study the impact of the Allee effect and prey refuge on the stability of a discrete time predator–prey system. We focus on the stability behavior of the system with the Allee effect in predator, prey and both populations. Based on the combination of analytical and numerical results, we observe that: (1) the Allee effect stabilizes the systems dynamics in a moderate value of prey refuge. (2) For a large fraction of prey refuge no significant improvement in stability is observed due to Allee effect. (3) Refuge may play an important role in managing the populations which are subject to the Allee effect. The population remains stable at an intermediate level of refuge parameter, whereas at relatively low and high refuge effect, prey exhibits chaotic oscillation. Such chaotic behavior is suppressed in the presence of Allee effect. The Allee mechanism and refuge are considered simultaneously on the populations and is shown to have a significant impact on the predator–prey dynamics that may be helpful in the conservation of endangered species.

scholarly journals One man’s trash is another man’s treasure - the effect of bacteria on phytoplankton-zooplankton interactions in chemostat systems

2018 ◽  
Author(s):  
M Raatz ◽  
S Schälicke ◽  
M Sieber ◽  
A Wacker ◽  
U Gaedke
Keyword(s):  
Population Dynamics ◽  
Carbon Sources ◽  
Evolutionary Processes ◽  
Experimental Conditions ◽  
Predator Prey ◽  
Complex Population ◽  
Dynamic Simulation Model ◽  
Flux Model ◽  
Aquatic Food ◽  
The Impact

AbstractChemostat experiments are employed to study predator-prey and other trophic interactions, frequently using phytoplankton-zooplankton systems. These experiments often use population dynamics as fingerprints of ecological and evolutionary processes, assuming that the contributions of all major actors to these dynamics are known. However, bacteria are often neglected although they are frequently present. We argue that even without external carbon sources bacteria may affect the experimental outcomes depending on experimental conditions and the physiological traits of bacteria, phytoplankton and zooplankton. Using a static carbon flux model and a dynamic simulation model we predict the minimum and maximum impact of bacteria on phytoplankton-zooplankton population dynamics. Under bacteria-suppressing conditions, we find that the effect of bacteria is indeed negligible and their omission justified. Under bacteria-favouring conditions, however, bacteria may strongly affect average biomasses. Furthermore, the population dynamics may become highly complex resulting in wrong conclusions if bacteria are not considered. Our model results provide suggestions to reduce the bacterial impact experimentally. Next to optimizing experimental conditions (e.g. the dilution rate) the appropriate choice of the zooplankton predator is decisive. Counterintuitively, bacteria have a larger impact if they are not ingested by the predator as high bacterial biomasses and complex population dynamics arise via competition for nutrients with the phytoplankton. Only if the predator is at least partly bacterivorous the impact of bacteria is minimized. Our results help to improve both the design of chemostat experiments and their interpretation and thus advance the study of ecological and evolutionary processes in aquatic food webs.

Carlisle Museum's Natural History Record Bureau, 1902–1912: Britain's first local environmental records centre

2020 ◽  
Vol 47 (1) ◽  
pp. 1-15
Author(s):  
Robin M. Sellers ◽  
Stephen Hewitt
Keyword(s):  
Natural History ◽  
Nature Reserve ◽  
Falco Peregrinus ◽  
Corvus Corax ◽  
Buteo Buteo ◽  
Local Newspaper ◽  
History Record ◽  
Economic Ornithology ◽  
The Impact

Carlisle Museum's Natural History Record Bureau, Britain's first local environmental records centre, collected and collated records, mainly of birds but including also mammals and fishes, from amateur naturalists. It initially covered an area of 80 kilometres around Carlisle, and later from Cumberland, Westmorland and the detached portion of Lancashire north of Morecambe Bay: in effect the modern-day county of Cumbria. At the end of each year, those records which had been accepted were logged in a special “Record Book”, and a summary published. For the first eight years of its ten-year existence (1902–1912), these were printed in the local newspaper, The Carlisle Journal, but from 1908 they also appeared in The Zoologist. Alongside the Record Bureau, the Museum undertook a number of other activities, including a short-lived attempt to establish a bird-ringing project, an investigation into the impact of black-headed gulls ( Chroicocephalus ridibundus) on farming and fisheries interests (an early example of economic ornithology), the setting up of Kingmoor Nature Reserve and the protection of nesting peregrines ( Falco peregrinus), buzzards ( Buteo buteo) and ravens ( Corvus corax). The effectiveness of the Natural History Record Bureau and the reasons for its demise are briefly discussed.

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