scholarly journals Investigating a trade-off between the quality of nest grown feathers and pace of development in an altricial bird.

2021 ◽  
Author(s):  
Conor C Taff ◽  
Brianna A Johnson ◽  
Allison T Anker ◽  
Alyssa M Rodriguez ◽  
Jennifer L Houtz ◽  
...  
Keyword(s):  
Life History Theory ◽  
Developmental Rate ◽  
Trade Off ◽  
Trade Offs ◽  
Risk Of Predation ◽  
Provisioning Rate ◽  
Negative Trait ◽  
Specific Trait ◽  
Specific Association ◽  
Trait Associations

Life history theory provides a framework for understanding how trade-offs generate negative trait associations. Among nestling birds, developmental rate, risk of predation, and lifespan covary, but some associations are only found within species while others are only observed between species. A recent comparative study suggests that allocation trade-offs may be alleviated by disinvestment in ephemeral traits, such as nest-grown feathers, that are quickly replaced. However, direct resource allocation trade-offs cannot be inferred from inter-specific trait-associations without complementary intra-specific studies. Here, we asked whether there is evidence for a within-species allocation trade-off between feather quality and developmental speed in tree swallows (Tachycineta bicolor). Consistent with the idea that ephemeral traits are deprioritized, nest-grown feathers had lower barb density than adult feathers. However, despite substantial variation in fledging age among nestlings, there was no evidence for a negative association between developmental pace and feather quality. Furthermore, accounting for differences in resource availability by considering provisioning rate and a nest predation treatment did not reveal a trade-off that was masked by variation in resources. Our results are most consistent with the idea that the inter-specific association between development and feather quality arises from adaptive specialization, rather than from a direct allocation trade-off.

scholarly journals Trade-off between age of first reproduction and survival in a female primate

2009 ◽  
Vol 5 (3) ◽  
pp. 339-342 ◽  
Author(s):  
Gregory E. Blomquist
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Rhesus Macaques ◽  
Human Study ◽  
Genetic Correlations ◽  
Adult Survival ◽  
Trade Off ◽  
Trade Offs ◽  
Female Life History ◽  
First Reproduction

Trade-offs are central to life-history theory but difficult to document. Patterns of phenotypic and genetic correlations in rhesus macaques, Macaca mulatta —a long-lived, slow-reproducing primate—are used to test for a trade-off between female age of first reproduction and adult survival. A strong positive genetic correlation indicates that female macaques suffer reduced adult survival when they mature relatively early and implies primate senescence can be explained, in part, by antagonistic pleiotropy. Contrasts with a similar human study implicate the extension of parental effects to later ages as a potential mechanism for circumventing female life-history trade-offs in human evolution.

scholarly journals Anomalous invasion dynamics due to dispersal polymorphism and dispersal-reproduction trade-offs

2020 ◽  
Author(s):  
Vincent A. Keenan ◽  
Stephen J. Cornell
Keyword(s):  
Life History Theory ◽  
Invasion Speed ◽  
Complex Behaviour ◽  
Trade Off ◽  
Invasion Dynamics ◽  
Population Growth Rates ◽  
Trade Offs ◽  
Invasion Fronts ◽  
Wide Range ◽  
Dispersal Polymorphism

AbstractDispersal polymorphism and mutation play significant roles during biological invasions, potentially leading to evolution and complex behaviour such as accelerating or decelerating invasion fronts. However, life history theory predicts that reproductive fitness — another key determinant of invasion dynamics – may be lower for more dispersive strains. Here, we use a mathematical model to show that unexpected invasion dynamics emerge from the combination of heritable dispersal polymorphism, dispersal-fitness trade-offs, and mutation between strains. We show that the invasion dynamics are determined by the trade-off relationship between dispersal and population growth rates of the constituent strains. We find that invasion dynamics can be “anomalous” (i.e. faster than any of the strains in isolation), but that the ultimate invasion speed is determined by the traits of at most two strains. The model is simple but generic, so we expect the predictions to apply to a wide range of ecological, evolutionary or epidemiological invasions.

FORAGING TRADE-OFFS AND PREDATOR INSPECTION IN AN OSTARIOPHYSAN FISH: SWITCHING FROM CHEMICAL TO VISUAL CUES

Behaviour ◽  
2000 ◽  
Vol 137 (2) ◽  
pp. 181-195 ◽  
Author(s):  
Joseph Cowan ◽  
Grant Brown
Keyword(s):  
Yellow Perch ◽  
Visual Cues ◽  
Chemical Cues ◽  
Potential Predator ◽  
Trade Off ◽  
Predator Inspection ◽  
Trade Offs ◽  
Risk Of Predation ◽  
Ad Libitum ◽  
Predator Behaviour

AbstractUnder laboratory conditions, we investigated the presence of a foraging trade-off in the chemical predator inspection behaviour of finescale dace (Chrosomus neogaeus). Dace were fed ad libitum, or food deprived for 24 or 48 hours and allowed to inspect a live yellow perch (Perca flavescens) in the presence of the chemical cues of a perch fed dace (with alarm pheromone) or swordtails (Xiphophorus helleri; without alarm pheromones). Dace exposed to the odour of a perch fed swordtails exhibited no evidence of a trade-off in either anti-predator behaviour or predator inspection behaviour. When fed ad libitum and exposed to the odour of a perch fed dace, individuals exhibited significantly greater anti-predator behaviour (increased shoaling, decreased area use and greater frequency of dashing and freezing behaviour) when compared to the swordtail diet control. Predator inspection behaviour was also significantly affected (increased latency to inspect and minimum distance approached towards the predator and fewer inspectors per visit). However, when food deprived for 24 or 48 hours, dace exhibited no differences in either anti-predator or predator inspection behaviour when exposed to the odour of perch fed dace versus perch fed swordtails. These data demonstrate that predator inspection behaviour based on the chemical cues of a potential predator is subject to foraging trade-offs and that individual prey may reduce their overall risk of predation by increasing the use of visual cues.

scholarly journals Anomalous invasion dynamics due to dispersal polymorphism and dispersal–reproduction trade-offs

2021 ◽  
Vol 288 (1942) ◽  
pp. 20202825
Author(s):  
Vincent A. Keenan ◽  
Stephen J. Cornell
Keyword(s):  
Life History Theory ◽  
Invasion Speed ◽  
Complex Behaviour ◽  
Trade Off ◽  
Invasion Dynamics ◽  
Population Growth Rates ◽  
Trade Offs ◽  
Invasion Fronts ◽  
Wide Range ◽  
Dispersal Polymorphism

Dispersal polymorphism and mutation play significant roles during biological invasions, potentially leading to evolution and complex behaviour such as accelerating or decelerating invasion fronts. However, life-history theory predicts that reproductive fitness—another key determinant of invasion dynamics—may be lower for more dispersive strains. Here, we use a mathematical model to show that unexpected invasion dynamics emerge from the combination of heritable dispersal polymorphism, dispersal-fitness trade-offs, and mutation between strains. We show that the invasion dynamics are determined by the trade-off relationship between dispersal and population growth rates of the constituent strains. We find that invasion dynamics can be ‘anomalous’ (i.e. faster than any of the strains in isolation), but that the ultimate invasion speed is determined by the traits of, at most, two strains. The model is simple but generic, so we expect the predictions to apply to a wide range of ecological, evolutionary, or epidemiological invasions.

scholarly journals Faster reproductive rates trade off against offspring growth in wild chimpanzees

2016 ◽  
Vol 113 (28) ◽  
pp. 7780-7785 ◽  
Author(s):  
Melissa Emery Thompson ◽  
Martin N. Muller ◽  
Kris Sabbi ◽  
Zarin P. Machanda ◽  
Emily Otali ◽  
...  
Keyword(s):  
Life History Theory ◽  
Reproductive Rate ◽  
Offspring Quality ◽  
Creatinine Excretion ◽  
Trade Off ◽  
Older Mothers ◽  
Trade Offs ◽  
Offspring Growth ◽  
Reproductive Rates ◽  
Do So

Life history theory predicts a trade-off between offspring quality and quantity. Among large-bodied mammals, prolonged lactation and infant dependence suggest particularly strong potential for a quality–quantity trade-off to exist. Humans are one of the only such species to have been examined, providing mixed evidence under a peculiar set of circumstances, including extensive nutritional provisioning by nonmothers and extrasomatic wealth transmission. Here, we examine trade-offs between reproductive rate and one aspect of offspring quality (body size) in wild chimpanzees (Pan troglodytes schweinfurthii), a species with long periods of infant dependence and little direct provisioning. Juvenile lean body mass, estimated using urinary creatinine excretion, was positively associated with the interval to the next sibling’s birth. These effects persisted into adolescence and were not moderated by maternal identity. Maternal depletion could not explain poor offspring growth, as older mothers had larger offspring, and low maternal energy balance during lactation predicted larger, not smaller, juvenile size. Instead, our data suggest that offspring growth suffers when mothers wean early to invest in new reproductive efforts. These findings indicate that chimpanzee mothers with the resources to do so prioritize production of new offspring over prolonged investment in current offspring.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

The Effects of Decision Time on Perceptions of Decisions and Decision Makers in (Moral) Trade-Off Scenarios

2019 ◽  
Author(s):  
Anna Katharina Spälti ◽  
Mark John Brandt ◽  
Marcel Zeelenberg
Keyword(s):  
Decision Process ◽  
Decision Time ◽  
Decision Makers ◽  
Process Information ◽  
Total N ◽  
Trade Off ◽  
Financial Gain ◽  
Trade Offs ◽  
Sacred Values ◽  
Moral Context

People often have to make trade-offs. We study three types of trade-offs: 1) "secular trade-offs" where no moral or sacred values are at stake, 2) "taboo trade-offs" where sacred values are pitted against financial gain, and 3) "tragic trade-offs" where sacred values are pitted against other sacred values. Previous research (Critcher et al., 2011; Tetlock et al., 2000) demonstrated that tragic and taboo trade-offs are not only evaluated by their outcomes, but are also evaluated based on the time it took to make the choice. We investigate two outstanding questions: 1) whether the effect of decision time differs for evaluations of decisions compared to decision makers and 2) whether moral contexts are unique in their ability to influence character evaluations through decision process information. In two experiments (total N = 1434) we find that decision time affects character evaluations, but not evaluations of the decision itself. There were no significant differences between tragic trade-offs and secular trade-offs, suggesting that the decisions structure may be more important in evaluations than moral context. Additionally, the magnitude of the effect of decision time shows us that decision time, may be of less practical use than expected. We thus urge, to take a closer examination of the processes underlying decision time and its perception.

Predicting Undesired Treatment Outcome in Mental Healthcare: Machine Learning Study (Preprint)

2019 ◽  
Author(s):  
Kasper Van Mens ◽  
Joran Lokkerbol ◽  
Richard Janssen ◽  
Robert de Lange ◽  
Bea Tiemens
Keyword(s):  
Machine Learning ◽  
Treatment Outcome ◽  
Mental Health Treatment ◽  
Mental Healthcare ◽  
Machine Learning Algorithms ◽  
Gradient Boosting ◽  
Trade Off ◽  
Trade Offs ◽  
Outcome Monitoring ◽  
Extreme Gradient Boosting

BACKGROUND It remains a challenge to predict which treatment will work for which patient in mental healthcare. OBJECTIVE In this study we compare machine algorithms to predict during treatment which patients will not benefit from brief mental health treatment and present trade-offs that must be considered before an algorithm can be used in clinical practice. METHODS Using an anonymized dataset containing routine outcome monitoring data from a mental healthcare organization in the Netherlands (n = 2,655), we applied three machine learning algorithms to predict treatment outcome. The algorithms were internally validated with cross-validation on a training sample (n = 1,860) and externally validated on an unseen test sample (n = 795). RESULTS The performance of the three algorithms did not significantly differ on the test set. With a default classification cut-off at 0.5 predicted probability, the extreme gradient boosting algorithm showed the highest positive predictive value (ppv) of 0.71(0.61 – 0.77) with a sensitivity of 0.35 (0.29 – 0.41) and area under the curve of 0.78. A trade-off can be made between ppv and sensitivity by choosing different cut-off probabilities. With a cut-off at 0.63, the ppv increased to 0.87 and the sensitivity dropped to 0.17. With a cut-off of at 0.38, the ppv decreased to 0.61 and the sensitivity increased to 0.57. CONCLUSIONS Machine learning can be used to predict treatment outcomes based on routine monitoring data.This allows practitioners to choose their own trade-off between being selective and more certain versus inclusive and less certain.

Challenges in the Empirical Study of Global Governance Legitimacy

2018 ◽  
Author(s):  
Steven Bernstein
Keyword(s):  
Empirical Study ◽  
Global Governance ◽  
Research Agenda ◽  
Cultural Factors ◽  
Theory Building ◽  
Trade Off ◽  
Trade Offs ◽  
Different Types ◽  
Political Communities

This commentary discusses three challenges for the promising and ambitious research agenda outlined in the volume. First, it interrogates the volume’s attempts to differentiate political communities of legitimation, which may vary widely in composition, power, and relevance across institutions and geographies, with important implications not only for who matters, but also for what gets legitimated, and with what consequences. Second, it examines avenues to overcome possible trade-offs from gains in empirical tractability achieved through the volume’s focus on actor beliefs and strategies. One such trade-off is less attention to evolving norms and cultural factors that may underpin actors’ expectations about what legitimacy requires. Third, it addresses the challenge of theory building that can link legitimacy sources, (de)legitimation practices, audiences, and consequences of legitimacy across different types of institutions.

scholarly journals Toward Inclusive Landscape Governance in Contested Landscapes: Exploring the Contribution of Participatory Tools in the Upper Suriname River Basin

2021 ◽  
Author(s):  
Lisa Best ◽  
Kimberley Fung-Loy ◽  
Nafiesa Ilahibaks ◽  
Sara O. I. Ramirez-Gomez ◽  
Erika N. Speelman
Keyword(s):  
Land Use ◽  
River Basin ◽  
Scenario Planning ◽  
Community Members ◽  
Trade Off ◽  
3 Dimensional ◽  
Landscape Governance ◽  
Information Tools ◽  
Tribal Communities ◽  
Trade Offs

AbstractNowadays, tropical forest landscapes are commonly characterized by a multitude of interacting institutions and actors with competing land-use interests. In these settings, indigenous and tribal communities are often marginalized in landscape-level decision making. Inclusive landscape governance inherently integrates diverse knowledge systems, including those of indigenous and tribal communities. Increasingly, geo-information tools are recognized as appropriate tools to integrate diverse interests and legitimize the voices, values, and knowledge of indigenous and tribal communities in landscape governance. In this paper, we present the contribution of the integrated application of three participatory geo-information tools to inclusive landscape governance in the Upper Suriname River Basin in Suriname: (i) Participatory 3-Dimensional Modelling, (ii) the Trade-off! game, and (iii) participatory scenario planning. The participatory 3-dimensional modelling enabled easy participation of community members, documentation of traditional, tacit knowledge and social learning. The Trade-off! game stimulated capacity building and understanding of land-use trade-offs. The participatory scenario planning exercise helped landscape actors to reflect on their own and others’ desired futures while building consensus. Our results emphasize the importance of systematically considering tool attributes and key factors, such as facilitation, for participatory geo-information tools to be optimally used and fit with local contexts. The results also show how combining the tools helped to build momentum and led to diverse yet complementary insights, thereby demonstrating the benefits of integrating multiple tools to address inclusive landscape governance issues.

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