scholarly journals Daily activity rhythms, chronotypes, and risk-taking behavior in the signal crayfish

2021 ◽  
Author(s):  
Valerio Sbragaglia ◽  
Thomas Breithaupt
Keyword(s):  
Individual Differences ◽  
Risk Taking ◽  
Daily Activity ◽  
Freshwater Ecosystems ◽  
Behavioral Syndrome ◽  
Signal Crayfish ◽  
Activity Rhythms ◽  
Visual Predator ◽  
Time Periods ◽  
Risk Taking Behavior

Abstract Consistent inter-individual differences in daily activity rhythms (i.e., chronotypes) can have ecological consequences in determining access to food resources and avoidance of predators. The most common measure to characterize chronotypes in animals as well as humans is the onset of activity (i.e., early or late chronotypes). However, daily activity rhythms may also differ in the relative amount of activity displayed at particular time periods. Moreover, chronotypes may also be linked to other consistent inter-individual differences in behavior (i.e., personality), such as the propensity to take risks. Here, we used the signal crayfish Pacifastacus leniusculus to test the presence of chronotypes and risk-taking personality traits and a potential behavioral syndrome between these traits. We first exposed crayfish to 5 days of light–darkness to measure daily activity rhythms and then we applied a visual predator-simulating stimulus in 2 different contexts (neutral and food). Our results showed consistent (i.e., across 5 days) inter-individual differences in the relative nocturnal activity displayed in the early and middle, but not in the late part of darkness hours. Moreover, while crayfish displayed inter-individual differences in risk-taking behavior, these were not found to be consistent across 2 contexts. Therefore, we were not able to formally test a behavioral syndrome between these 2 traits. In conclusion, our study provides the first evidence of chronotypes in the relative amount of activity displayed at particular time periods. This could be a valuable information for applied ecological aspects related to the signal crayfish, which is a major invasive species of freshwater ecosystems.

scholarly journals Are “early birds” bolder? Early daily activity is not correlated with risk-taking behaviour in a major invasive species

2019 ◽  
Author(s):  
Valerio Sbragaglia ◽  
Thomas Breithaupt
Keyword(s):  
Invasive Species ◽  
Locomotor Activity ◽  
Biological Invasions ◽  
Risk Taking ◽  
Daily Activity ◽  
Behavioural Syndrome ◽  
Nocturnal Activity ◽  
Activity Rhythms ◽  
Behavioural Syndromes ◽  
Risk Taking Behavior

ABSTRACTDaily behavioural rhythms provide ecological advantages with respect to exploitation of food resources and avoidance of predation and recent studies suggested that timing of activity could form a behavioural syndrome with risk-taking behavior. Behavioural syndromes are often displayed by invasive species but the role of activity rhythms in biological invasions is unknown. Here, we investigated whether early nocturnal activity (the relative amount of locomotor activity displayed early in the night) and risk-taking behaviour (i.e. response to a scare stimulus) form a behavioural syndrome in a major invasive species, the signal crayfish (Pacifastacus leniusculus). We first characterized daily rhythms of locomotor activity over five days under controlled laboratory conditions and then scored the response to a scare stimulus across two different contexts (neutral and food) two days apart within the following six days. Crayfish displayed overall daily activity rhythms peaking in the first four hours of darkness. Both early nocturnal activity and risk-taking behaviour showed consistent inter-individual differences with repeatability scores of 0.20 and 0.35, respectively. However, the two behavioural traits were not correlated as in a behavioural syndrome. We argue that in contrast to other behavioural syndromes, a link between early nocturnal activity and risk-taking tendency would not be evolutionary stable as it dramatically increases predictability and therefore predatory pressure to individuals. We suggest that daily activity rhythms and risk-taking behavior can be important traits in understanding the adaptations underlying biological invasions or other processes of contemporary evolution.

A Possible Adjusting Procedure for Studying Outcomes of Risk-Taking

1998 ◽  
Vol 82 (3) ◽  
pp. 1047-1050 ◽  
Author(s):  
Mark R. Dixon ◽  
Linda J. Hayes ◽  
Ruth Anne Rehfeldt ◽  
Ralph E. Ebbs
Keyword(s):  
Individual Differences ◽  
Pilot Study ◽  
Risk Taking ◽  
Quantitative Measure ◽  
Original Equation ◽  
Future Risk ◽  
Risk Taking Behavior ◽  
Larger Sample ◽  
Concurrent Analysis

The purpose of this pilot study was to examine the role of consequences in the maintenance and termination of risk-taking behavior. In 1987 Ladouceur, Mayrand, and Tourigny proposed a quantitative measure of risk-taking based on roulette playing, but this metric did not include the outcome of that risk. Therefore, their original equation may be adjusted to incorporate a concurrent analysis of the consequences of risk-taking to understand better individual differences with respect to risk-taking behavior. An experiment with six subjects, 3 experienced and 3 inexperienced, who played roulette was used to evaluate the accuracy of the equation's predictions. Replication with a much larger sample is required to substantiate the suggestion that this adjustment would be more accurate than the original equation in predicting future risk-taking.

Zebrafish (Danio rerio) exhibit individual differences in risk-taking behavior during predator inspection

2005 ◽  
Vol 17 (1) ◽  
pp. 77-81 ◽  
Author(s):  
L.A. Dugatkin ◽  
M.A. McCall ◽  
R.G. Gregg ◽  
A. Cavanaugh ◽  
C. Christensen ◽  
...  
Keyword(s):  
Individual Differences ◽  
Danio Rerio ◽  
Risk Taking ◽  
Predator Inspection ◽  
Risk Taking Behavior

scholarly journals Using a robotic fish to investigate individual differences in social responsiveness in the guppy

2018 ◽  
Author(s):  
David Bierbach ◽  
Tim Landgraf ◽  
Pawel Romanczuk ◽  
Juliane Lukas ◽  
Hai Nguyen ◽  
...  
Keyword(s):  
Individual Differences ◽  
Risk Taking ◽  
Poecilia Reticulata ◽  
Activity Level ◽  
Social Responsiveness ◽  
Behavioral Syndrome ◽  
Fish Robot ◽  
Behavioral Traits ◽  
Biomimetic Robots ◽  
The Social

AbstractResponding towards the actions of others is one of the most important behavioral traits whenever animals of the same species interact. Mutual influences among interacting individuals may modulate the social responsiveness seen and thus makes it often difficult to study the level and variation of individuality in responsiveness. Here, biomimetic robots (BRs) that are accepted as conspecifics but controlled by the experimenter can be a useful tool. Studying the interactions of live animals with BRs allows pinpointing the live animal’s level of responsiveness by removing confounding mutuality. In this paper, we show that live guppies (Poecilia reticulata) exhibit consistent differences among each other in their responsiveness when interacting with a biomimetic fish robot - ‘Robofish’ - and a live companion. It has been repeatedly suggested that social responsiveness correlates with other individual behavioral traits like risk-taking behavior (‘boldness’) or activity level. We tested this assumption in a second experiment. Interestingly, our detailed analysis of individual differences in social responsiveness using the Robofish, suggests that responsiveness is an independent trait, not part of a larger behavioral syndrome formed by boldness and activity.

scholarly journals Harvesting-induced evolution of collective risk-taking behavior and changes to the circadian system in a fish

2019 ◽  
Author(s):  
Valerio Sbragaglia ◽  
Jose Fernando López-Olmeda ◽  
Elena Frigato ◽  
Cristiano Bertolucci ◽  
Robert Arlinghaus
Keyword(s):  
Risk Taking ◽  
Daily Activity ◽  
Activity Patterns ◽  
Circadian System ◽  
Selective Mortality ◽  
Transcription Profiles ◽  
Large Size ◽  
Collective Risk ◽  
Evolutionary Changes ◽  
Risk Taking Behavior

ABSTRACTIntensive and trait-selective harvesting of fish and wildlife can cause evolutionary changes in a range of life-history and behavioural traits. These changes might in turn alter the circadian system both at behavioral and molecular levels, with knock-on effects on daily physiological processes and behavioural outputs. We examined the evolutionary impact of size-selective mortality on collective risk-taking behavior and the circadian system in a model fish species. We exposed zebrafish (Danio rerio) to either large or small size-selective mortality relative to a control over five generations, followed by eight generations during which harvesting halted to remove maternal effects. Large size-selective mortality typical of many fisheries and specialized predators targeting larger size classes decreased collective risk-taking behavior compared to controls. The opposite occurred in response to small size-selective mortality typical of specialized fisheries and most gape-limited predators. The evolutionary changes in risk-taking behavior were linked to daily activity rhythms in response to small size-selective mortality, while no changes were observed in response to large size-selective mortality. We also found changes in the molecular circadian core clockwork in response to both size selective mortality treatments. These changes disappeared in the clock output pathway, resulting in similar transcription profiles of both size-selected lines. The results suggest a switch downstream to the molecular circadian core clockwork, leading to overall similar daily activity patterns across selection lines. Our experimental harvest left an evolutionary legacy in collective risktaking behavior and relatedly in the circadian system, both at behavioral and molecular levels. Changes to risk-sensitive behavior of exploited organisms can have far-reaching consequences for how space and time is used and may also affect catchability and natural predation.

Predicting Stock Market Performance

2020 ◽  
pp. 1-10
Author(s):  
Thomas Plieger ◽  
Thomas Grünhage ◽  
Éilish Duke ◽  
Martin Reuter
Keyword(s):  
Stock Market ◽  
Risk Taking ◽  
Life Stress ◽  
Price Volatility ◽  
Individual Characteristics ◽  
Self Report ◽  
Financial Behavior ◽  
Market Simulation ◽  
Stock Market Performance ◽  
Risk Taking Behavior

Abstract. Gender and personality traits influence risk proneness in the context of financial decisions. However, most studies on this topic have relied on either self-report data or on artificial measures of financial risk-taking behavior. Our study aimed to identify relevant trading behaviors and personal characteristics related to trading success. N = 108 Caucasians took part in a three-week stock market simulation paradigm, in which they traded shares of eight fictional companies that differed in issue price, volatility, and outcome. Participants also completed questionnaires measuring personality, risk-taking behavior, and life stress. Our model showed that being male and scoring high on self-directedness led to more risky financial behavior, which in turn positively predicted success in the stock market simulation. The total model explained 39% of the variance in trading success, indicating a role for other factors in influencing trading behavior. Future studies should try to enrich our model to get a more accurate impression of the associations between individual characteristics and financially successful behavior in context of stock trading.

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