scholarly journals Both Prey and Predator Features Determine Predation Risk and Survival of Schooling Prey

2021 ◽  
Author(s):  
Jolle W. Jolles ◽  
Matthew M.G. Sosna ◽  
Geoffrey P. F. Mazue ◽  
Colin R Twomey ◽  
Joseph Bak-Coleman ◽  
...  
Keyword(s):  
Decision Making ◽  
Predation Risk ◽  
Northern Pike ◽  
Acceleration Response ◽  
Dynamic Nature ◽  
Maximum Acceleration ◽  
Schooling Fish ◽  
Social Grouping ◽  
Golden Shiners ◽  
Attack Strategy

Predation is one of the main evolutionary drivers of social grouping. While it is well appreciated that predation risk is likely not shared equally among individuals within groups, its detailed quantification has remained difficult due to the speed of attacks and the highly-dynamic nature of collective prey response. Here, using high-resolution tracking of solitary predators (Northern pike) hunting schooling fish (golden shiners), we not only provide detailed insights into predator decision-making but show which key spatial and kinematic features of predator and prey influence individual's risk to be targeted and survive attacks. Pike tended to stealthily approach the largest groups, and were often already inside the school when launching their attack, making prey in this frontal "strike zone" the most vulnerable to be targeted. From the prey's perspective, those fish in central locations, but relatively far from, and less aligned with, neighbours, were most likely to be targeted. While the majority of attacks (70%) were successful, targeted individuals that did manage to avoid capture exhibited a higher maximum acceleration response just before the attack and were further away from the pike's head. Our results highlight the crucial interplay between predators' attack strategy and response of prey in determining predation risk in mobile animal groups.

scholarly journals Seismic Response and Vibration Reduction Analysis of Suspended Structure under Wave Passage Excitation

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wenhua Cai ◽  
Bujun Yu ◽  
Fajong Wu ◽  
Jianhua Shao
Keyword(s):  
Seismic Response ◽  
Wave Velocity ◽  
Vibration Reduction ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Uniform Motion ◽  
Acceleration Response ◽  
Maximum Acceleration ◽  
Damping Effect ◽  
Suspended Structure

In order to study the influence of traveling wave effect on the seismic response and damping effect of suspended structure, a series of shaking table tests of the 1 : 20 suspended structure have been carried out to compare and analyze the dynamic responses of suspended structures under two points and a consistent input. The vibration damping effect and vibration reduction law of suspended structure are discussed at different apparent wave velocity and in the different connection. The research shows that the damping suspended structure has a good damping effect, and the amplitude reduction of the top displacement peak response is up to 15%, which corresponds to smaller apparent velocities. Moreover, the upper bound of the maximum acceleration response at the structures’ top under nonuniform input motions equals that of the uniform motion. However, there is a hysteresis in the acceleration response under wave travelling excitations, and the smaller the apparent wave velocity, the more obvious the hysteresis.

scholarly journals Ants show a leftward turning bias when exploring unknown nest sites

2014 ◽  
Vol 10 (12) ◽  
pp. 20140945 ◽  
Author(s):  
Edmund R. Hunt ◽  
Thomas O'Shea-Wheller ◽  
Gregory F. Albery ◽  
Tamsyn H. Bridger ◽  
Mike Gumn ◽  
...  
Keyword(s):  
Decision Making ◽  
Predation Risk ◽  
Temnothorax Albipennis ◽  
Present Evidence ◽  
Nest Sites ◽  
Migration Factors ◽  
Important Field ◽  
And Migration ◽  
Wall Following ◽  
Colony Level

Behavioural lateralization in invertebrates is an important field of study because it may provide insights into the early origins of lateralization seen in a diversity of organisms. Here, we present evidence for a leftward turning bias in Temnothorax albipennis ants exploring nest cavities and in branching mazes, where the bias is initially obscured by thigmotaxis (wall-following) behaviour. Forward travel with a consistent turning bias in either direction is an effective nest exploration method, and a simple decision-making heuristic to employ when faced with multiple directional choices. Replication of the same bias at the colony level would also reduce individual predation risk through aggregation effects, and may lead to a faster attainment of a quorum threshold for nest migration. We suggest the turning bias may be the result of an evolutionary interplay between vision, exploration and migration factors, promoted by the ants' eusociality.

Under pressure: predation risk defining mating investment in matured spider mite Tetranychus urticae

2020 ◽  
Vol 25 (8) ◽  
pp. 1359-1372
Author(s):  
Matheus S. Rocha ◽  
Lívia A. Celada ◽  
Everton N. L. Rodrigues ◽  
Luiz E. Costa-schmidt
Keyword(s):  
Decision Making ◽  
Predation Risk ◽  
Tetranychus Urticae ◽  
Laboratory Experiments ◽  
Spider Mite ◽  
Reproductive Effort ◽  
Spider Mites ◽  
Investment Behavior ◽  
Two Spotted Spider Mite ◽  
Mating Performance

The emergence of anti-predatory strategies for prey survival are ruled by the minimization of the encounters/interactions with potential predators, but at the same time by maximizing the access to limiting resources such as food or mating partners. Cues indicating predatory activity influence decision-making activities in the two-spotted spider mite Tetranychus urticae, such as dispersion, foraging activities, and reproductive effort.  However, anti-predatory strategies studied in spider mites generally considers mainly the female perspective (e.g. oviposition), leaving a gap in how T. urticae couples deal with predatory risk. Here, through laboratory experiments, we observed that matured spider mite couples were only affected by predation risk during the pre-copulatory stages of the mating process, especially when deciding to proceed in a mating opportunity. The mating performance of individuals was independent of their exposure to predation risk, suggesting that couples would adopt full investment behavior after opting to proceed in a mating attempt. Though our working hypothesis predicted predation risk interference throughout the entire mating process, we conclude that decision-making activities by spider mite during pre-copulatory stages act independently from copulatory stages associated to insemination.

Optimal Design of Television Packaging Based on Drop Analysis

2010 ◽  
Vol 156-157 ◽  
pp. 713-716
Author(s):  
Deng Feng Zhao ◽  
Guo Lu Ma ◽  
Guo Ying Zeng
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Response Curve ◽  
Equivalent Stress ◽  
Element Model ◽  
Optimization Method ◽  
Impact Response ◽  
Acceleration Response ◽  
Maximum Acceleration ◽  
Independent Components

Optimization method was applied to obtain optimal television packaging cushion for reducing drop impact response on television. At first, by establishing the parametric finite element model of television with packaging, the drop simulation was performed, and the equivalent stress distribution, acceleration response curve and other related parameters were obtained. Simulation shows that maximum acceleration is overload. Then, structural optimization of television with packaging was performed. The equivalent stress distribution and acceleration curves of optimal packaging and without optimal packaging for the independent components were studied. The results show that maximum acceleration is reduced and the cushioning performance is enhanced.

Variable predation risk and the dynamic nature of mosquito antipredator responses to chemical alarm cues

Chemoecology ◽  
2007 ◽  
Vol 17 (4) ◽  
pp. 223-229 ◽  
Author(s):  
Maud C. O. Ferrari ◽  
François Messier ◽  
Douglas P. Chivers
Keyword(s):  
Predation Risk ◽  
Alarm Cues ◽  
Dynamic Nature ◽  
Chemical Alarm Cues ◽  
Antipredator Responses

scholarly journals Consensus of travel direction is achieved by simple copying, not voting, in free-ranging goats

2021 ◽  
Vol 8 (2) ◽  
pp. 201128
Author(s):  
D. W. E. Sankey ◽  
L. R. O'Bryan ◽  
S. Garnier ◽  
G. Cowlishaw ◽  
P. Hopkins ◽  
...  
Keyword(s):  
Decision Making ◽  
Group Living ◽  
Theoretical Models ◽  
Body Orientation ◽  
African Buffalo ◽  
Preferred Direction ◽  
Magnetometer Data ◽  
Golden Shiners ◽  
Active Communication ◽  
Free Ranging

For group-living animals to remain cohesive they must agree on where to travel. Theoretical models predict shared group decisions should be favoured, and a number of empirical examples support this. However, the behavioural mechanisms that underpin shared decision-making are not fully understood. Groups may achieve consensus of direction by active communication of individual preferences (i.e. voting), or by responding to each other's orientation and movement (i.e. copying). For example, African buffalo ( Syncerus caffer ) are reported to use body orientation to vote and indicate their preferred direction to achieve a consensus on travel direction, while golden shiners ( Notemigonus crysoleucas ) achieve consensus of direction by responding to the movement cues of their neighbours. Here, we present a conceptual model (supported by agent-based simulations) that allows us to distinguish patterns of motion that represent voting or copying. We test our model predictions using high-resolution GPS and magnetometer data collected from a herd of free-ranging goats ( Capra aegagrus hircus ) in the Namib Desert, Namibia. We find that decisions concerning travel direction were more consistent with individuals copying one another's motion and find no evidence to support the use of voting with body orientation. Our findings highlight the role of simple behavioural rules for collective decision-making by animal groups.

Inferring Actors’ Emotions

2018 ◽  
Author(s):  
Robin Markwica
Keyword(s):  
Decision Making ◽  
Empirical Study ◽  
Choice Behavior ◽  
Process Philosophy ◽  
External Representations ◽  
Dynamic Nature ◽  
Constitutive Analysis ◽  
Interpretive Approach ◽  
The Relationship ◽  
Methodological Strategy

The empirical study of phenomena as evanescent and elusive as emotions raises thorny methodological challenges. Chapter 3 proposes a methodological strategy for inferring emotions from their external representations and for gauging their influence on decision-making. Borrowing techniques from linguistics, psychology, and sociology, the chapter combines qualitative sentiment analysis with an interpretive approach to infer actors’ emotions and their intensity from textual sources. It delineates a number of methodological steps for recovering the cultural, strategic, and individual context of emotions. Moreover, the chapter uses process philosophy to develop a process form of explanation as an alternative to conventional causal and constitutive analysis, neither of which is suitable for theorizing the relationship between emotions and decision-making. This process account is not only able to grasp the dynamic nature of emotions; it is also better suited to trace the influence of emotions on choice behavior.

Approaching Migration: The Dynamic Nature of Human Mobility

2018 ◽  
Vol 15 (3) ◽  
pp. 301-302
Author(s):  
Jeffrey H. Cohen
Keyword(s):  
Decision Making ◽  
Dynamic Process ◽  
Human Mobility ◽  
The State ◽  
Dynamic Nature ◽  
Meso Level ◽  
Key Events ◽  
International Border ◽  
Social Landscapes

Migration is a dynamic process, difficult to frame and even harder to predict.  Unlike other key events (most specifically death), migration follows uncertain pathways and reflects securities and insecurities that tend to play out across diverse social landscapes and include movers, non-movers as well as  households and communities.  Nevertheless, as the articles in this volume of Migration Letters reveal we continue to explore migration and its history; model decision-making and the challenges that movers face as they select new pathways; and explore as well as predict outcomes of remittance practices, policymaking and status. The articles in this issue and throughout our journal are often focused on what Tomas Faist (and others) call the crucial meso-level (Faist 1997).  This is the space where the decisions of individuals encounter and engage the household and other movers as well as non-movers, the community and the state.   The encounters and engagements that occur at the meso-level remind us that migration is not a simple decision, made by an independent actor. Rather, the decisions to move—whether as a migrant or refugee; whether across an international border or across a town—are complex and include many different voices, challenges and trials.

THE EVOLUTION OF SPIN-OFF VENTURES: AN INTEGRATED MODEL

2010 ◽  
Vol 07 (01) ◽  
pp. 53-70 ◽  
Author(s):  
SVEN H. DE CLEYN ◽  
JOHAN BRAET
Keyword(s):  
Decision Making ◽  
Case Studies ◽  
Real Life ◽  
Integrated Model ◽  
Research Field ◽  
Integrative Model ◽  
Life Situation ◽  
Dynamic Nature ◽  
The Real ◽  
Real Life Situation

The article aims to give an overview of the main models in the spin-off research field. The main evolution models known in literature will be analyzed. The evolution models will be discussed in increasing order of complexity. However, the existing models will prove to be inadequate to reflect the real-life situation. Therefore, a new integrative model will be discussed in detail, illustrated by using 17 case studies of Belgian academic spin-offs. The model incorporates the dynamic nature of academic spin-off evolution and the major peripheral aspects. It can be used by practitioners and academics to enhance reproducibility and decision making.

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