scholarly journals Size-selective mortality fosters ontogenetic changes in collective risk-taking behaviour in zebrafish, Danio rerio

2021 ◽  
Author(s):  
Tamal Roy ◽  
Robert Arlinghaus
Keyword(s):  
Danio Rerio ◽  
Risk Taking ◽  
Direct Selection ◽  
Small Fish ◽  
Control Line ◽  
Selective Mortality ◽  
Predation Threat ◽  
Size Selection ◽  
Risk Of Predation ◽  
The Impact

AbstractSize-selective mortality is common in fish populations and can operate either in a positive size-selective fashion or be negatively size-selective. Through various mechanisms (like genetic correlations among behaviour and life-history traits or direct selection on behaviour co-varying with growth rate or size-at-maturation), both positive- and negative size-selection can result in evolutionary changes in behavioural traits. Theory suggests that size-selection alone favours boldness, but little experimental evidence exists about whether and to what extent size-selection can trigger its evolution. Here we investigated the impact of size-selective mortality on boldness across ontogeny using three experimental lines of zebrafish (Danio rerio) generated through positive (large-harvested), negative (small-harvested) and random (control line) size-selective mortality for five generations. We measured risk-taking during feeding (boldness) under simulated aerial predation threat and in presence of a live cichlid. We found that boldness decreased with ontogenetic age under aerial predation threat, and the small-harvested line was consistently bolder than controls. Collective personality emerged post larval stages among the selection lines. In presence of a cichlid, the large-harvested line was bolder at the highest risk of predation. The large-harvested line showed higher variability and plasticity in boldness across life stages and predation risks. Collectively, our results demonstrate that size-selective harvesting may evolutionarily alter risk-taking tendency. Size-selection alone favours boldness when selection acts on small fish. Selection typical of fisheries operating on large fish favours boldness at the highest risk of predation and increases behavioural variability and plasticity. There was no evidence for positive size-selection favouring evolution of shyness.

scholarly journals Size Selective Harvesting Does Not Result in Reproductive Isolation among Experimental Lines of Zebrafish, Danio rerio: Implications for Managing Harvest-Induced Evolution

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 113
Author(s):  
Tamal Roy ◽  
Kim Fromm ◽  
Valerio Sbragaglia ◽  
David Bierbach ◽  
Robert Arlinghaus
Keyword(s):  
Body Size ◽  
Reproductive Isolation ◽  
Danio Rerio ◽  
The Body ◽  
Secondary Contact ◽  
Control Line ◽  
Selective Mortality ◽  
Size Classes ◽  
Size Selection ◽  
Natural Predation

Size-selective mortality is common in fish stocks. Positive size-selection happens in fisheries where larger size classes are preferentially targeted while gape-limited natural predation may cause negative size-selection for smaller size classes. As body size and correlated behavioural traits are sexually selected, harvest-induced trait changes may promote prezygotic reproductive barriers among selection lines experiencing differential size-selective mortality. To investigate this, we used three experimental lines of zebrafish (Danio rerio) exposed to positive (large-harvested), negative (small-harvested) and random (control line) size-selective mortality for five generations. We tested prezygotic preferences through choice tests and spawning trials. In the preference tests without controlling for body size, we found that females of all lines preferred males of the generally larger small-harvested line. When the body size of stimulus fish was statistically controlled, this preference disappeared and a weak evidence of line-assortative preference emerged, but only among large-harvested line fish. In subsequent spawning trials, we did not find evidence for line-assortative reproductive allocation in any of the lines. Our study suggests that size-selection due to fisheries or natural predation does not result in reproductive isolation. Gene flow between wild-populations and populations adapted to size-selected mortality may happen during secondary contact which can speed up trait recovery.

Do Incentives Contracts Lead to Higher Risk-taking? The Impact of Executives' Characteristics

2019 ◽  
Author(s):  
François Desmoulins-Lebeault ◽  
Jean-Francois Gajewski ◽  
Luc Meunier
Keyword(s):  
Risk Taking ◽  
The Impact

The impact of index‐insured loans on credit market participation and risk‐taking

2021 ◽  
Vol 52 (1) ◽  
pp. 141-156
Author(s):  
Richard A. Gallenstein ◽  
Jon Einar Flatnes ◽  
John P. Dougherty ◽  
Abdoul G. Sam ◽  
Khushbu Mishra
Keyword(s):  
Risk Taking ◽  
Credit Market ◽  
Market Participation ◽  
The Impact

scholarly journals Effects of the COVID-19 Pandemic on Sports Entrepreneurship

2020 ◽  
Vol 12 (20) ◽  
pp. 8493
Author(s):  
Paloma Escamilla-Fajardo ◽  
Juan M. Núñez-Pomar ◽  
Ferran Calabuig-Moreno ◽  
Ana M. Gómez-Tafalla
Keyword(s):  
Service Quality ◽  
Risk Taking ◽  
Non Profit ◽  
Paired Sample ◽  
Sports Clubs ◽  
Before And After ◽  
The Impact ◽  
The Relationship ◽  
Linear Regressions ◽  
Crisis Situations

Sports entrepreneurship has been considered an important part of sports organisations when overcoming crisis situations. The aim of this study is to determine the impact of the crisis derived from COVID-19 on sports entrepreneurship and whether there are differences in the prediction of entrepreneurship on service quality in non-profit sports clubs. To this end, 145 sports clubs were analysed before and after the outbreak of the virus in society. Paired sample-t tests were carried out to determine the differences in variables studied before (Time I) and after (Time II) the COVID-19 outbreak, and correlations and hierarchical linear regressions were used to analyse the relationship between the variables studied in the two different stages. The results obtained show that risk-taking and innovation are significantly higher after the appearance of COVID-19, while proactivity has not undergone significant changes. Finally, the relationship between sports entrepreneurship and service quality is positive and significant in both stages but stronger before the crisis.

Should Fast-Food Franchisees Pursue Entrepreneurial Orientation?

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ehsan Asgharian ◽  
Misagh Tasavori ◽  
Jim Andersén
Keyword(s):  
Firm Performance ◽  
Significant Role ◽  
Risk Taking ◽  
Entrepreneurial Orientation ◽  
Fast Food ◽  
Business Systems ◽  
Unidimensional Construct ◽  
Different Dimensions ◽  
Competitive Aggressiveness ◽  
The Impact

Abstract Although it is widely accepted that entrepreneurial orientation (EO) improves firm performance, scholars have advised that particular attention should be paid to the context. In this research, we investigate a less explored context of franchising where business systems and procedures are usually dictated to franchisees by franchisors. Therefore, whether a franchisor should allow franchisees to pursue EO (innovativeness, proactiveness, risk-taking, competitive aggressiveness, and autonomy) is not clear. In the context of franchising, the majority of prior studies have mainly focused on the employment of EO as a unidimensional construct and at the franchisor level. In this research, we take a bottom-up perspective and evaluate the impact of different dimensions of EO on franchisees’ performance. Our analysis of a multi-group of 183 restaurant franchisees located in Sweden and Iran reveals that only the pursuit of proactiveness and competitive aggressiveness improves a franchisee’s performance and other dimensions do not play a significant role in improving performance in this context.

Behavioural responses of voles to simulated risk of predation by a native and an alien mustelid: an odour manipulation experiment

2010 ◽  
Vol 37 (4) ◽  
pp. 273 ◽  
Author(s):  
Karen Fey ◽  
Peter B. Banks ◽  
Hannu Ylönen ◽  
Erkki Korpimäki
Keyword(s):  
Baltic Sea ◽  
Predation Risk ◽  
Myodes Glareolus ◽  
The Baltic Sea ◽  
Short Term ◽  
Behavioural Responses ◽  
Alien Predator ◽  
Risk Of Predation ◽  
The Baltic ◽  
The Impact

Context. Potential mammalian prey commonly use the odours of their co-evolved predators to manage their risks of predation. But when the risk comes from an unknown source of predation, odours might not be perceived as dangerous, and anti-predator responses may fail, except possibly if the alien predator is of the same archetype as a native predator. Aims. In the present study we examined anti-predator behavioural responses of voles from the outer archipelagos of the Baltic Sea, south-western Finland, where they have had no resident mammalian predators in recent history. Methods. We investigated responses of field voles (Microtus agrestis) to odours of native least weasels (Mustela nivalis) and a recently invading alien predator, the American mink (Mustela vison), in laboratory. We also studied the short-term responses of free-ranging field voles and bank voles (Myodes glareolus) to simulated predation risk by alien mink on small islands in the outer archipelago of the Baltic Sea. Key results. In the laboratory, voles avoided odour cues of native weasel but not of alien mink. It is possible that the response to mink is a context dependent learned response which could not be induced in the laboratory, whereas the response to weasel is innate. In the field, however, voles reduced activity during their normal peak-activity times at night as a response to simulated alien-mink predation risk. No other shifts in space use or activity in safer microhabitats or denser vegetation were apparent. Conclusions. Voles appeared to recognise alien minks as predators from their odours in the wild. However, reduction in activity is likely to be only a short-term immediate response to mink presence, which is augmented by longer-term strategies of habitat shift. Because alien mink still strongly suppresses vole dynamics despite these anti-predator responses, we suggest that behavioural naiveté may be the primary factor in the impact of an alien predator on native prey. Implications. Prey naiveté has long been considered as the root cause of the devastating impacts of alien predators, whereby native prey simply fail to recognise and respond to the novel predation risk. Our results reveal a more complex form of naiveté whereby native prey appeared to recognise alien predators as a threat but their response is ultimately inadequate. Thus, recognition alone is unlikely to afford protection for native prey from alien-predator impacts. Thus, management strategies that, for example, train prey in recognition of novel threats must induce effective responses if they are expected to succeed.

scholarly journals The Scams Among Us: Who Falls Prey and Why

2021 ◽  
pp. 096372142199548
Author(s):  
Yaniv Hanoch ◽  
Stacey Wood
Keyword(s):  
Risk Taking ◽  
Current Knowledge ◽  
Demographic Characteristics ◽  
Popular Media ◽  
Personality Variables ◽  
The Impact

Not a week goes by without stories about scams appearing in popular media outlets. Given the ease with which scams can be circulated, they have become one of the most common crimes globally, inflicting high emotional, financial, and psychological tolls on millions of individuals. Despite their profound and pervasive impact, researchers know relatively little about why some individuals fall victim to scams but others remain immune to the techniques utilized by scammers to lure potential victims. For example, research thus far provides mixed results about the impact of demographic characteristics (e.g., age) as well as personality variables (e.g., risk taking) on individuals’ susceptibility to scams. Even less is known about how the nature or type of scam affects an individual’s susceptibility. Gaining a deeper understanding of these issues is the key to being able to develop preventive programs and reduce the prevalence of victimization. Here, we discuss some promising directions, existing gaps in current knowledge, and the need for decision scientists to address this important problem.

Shareholder risk-taking incentives in the presence of contingent capital

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahmoud Fatouh ◽  
Ayowande A. McCunn
Keyword(s):  
Risk Taking ◽  
Banking System ◽  
Capital Requirements ◽  
Content Type ◽  
Basic Model ◽  
Conversion Rates ◽  
A Minor ◽  
The Impact ◽  
Practical Implications

Purpose This paper aims to present a model of shareholders’ willingness to exert effort to reduce the likelihood of bank distress and the implications of the presence of contingent convertible (CoCo) bonds in the liabilities structure of a bank. Design/methodology/approach This study presents a basic model about the moral hazard surrounding shareholders willingness to exert effort that increases the likelihood of a bank’s success. This study uses a one-shot game and so do not capture the effects of repeated interactions. Findings Consistent with the existing literature, this study shows that the direction of the wealth transfer at the conversion of CoCo bonds determines their impact on shareholder risk-taking incentives. This study also finds that “anytime” CoCos (CoCo bonds trigger-able anytime at the discretion of managers) have a minor advantage over regular CoCo bonds, and that quality of capital requirements can reduce the risk-taking incentives of shareholders. Practical implications This study argues that shareholders can also use manager-specific CoCo bonds to reduce the riskiness of the bank activities. The issuance of such bonds can increase the resilience of individual banks and the whole banking system. Regulators can use restrictions on conversion rates and/or requirements on the quality of capital to address the impact of CoCo bonds issuance on risk-taking incentives. Originality/value To model the risk-taking incentives, authors generally modify the asset processes to introduce components that reflect asymmetric information between CoCo holders and shareholders and/or managers. This paper follows a simpler method similar to that of Holmström and Tirole (1998).

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