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Dynamics of among-individual behavioral variation over adult lifespan in a wild insect.

Fisher DN, David M, Tregenza T, Rodríguez-Muñoz R - Behav. Ecol. (2015)

Bottom Line: All 4 traits showed among-individual variance in mean levels of expression across the adult lifespan, but no significant differences in how rapidly expression changed with age.Our findings reveal seldom examined changes in variance components over the adult lifetime of wild individuals.Such changes will have important implications for the relationship between behavioral traits, life-histories, and fitness and the consequences of selection on wild individuals.

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and.

ABSTRACT

Investigating patterns of among and within-individual trait variation in populations is essential to understanding how selection shapes phenotypes. Behavior is often the most flexible aspect of the phenotype, and to understand how it is affected by selection, we need to examine how consistent individuals are. However, it is not well understood whether among-individual differences tend to remain consistent over lifetimes, or whether the behavior of individuals relative to one another varies over time. We examined the dynamics of 4 behavioral traits (tendency to leave a refuge, shyness, activity, and exploration) in a wild population of field crickets (Gryllus campestris). We tagged individuals and then temporarily removed them from their natural environment and tested them under laboratory conditions. All 4 traits showed among-individual variance in mean levels of expression across the adult lifespan, but no significant differences in how rapidly expression changed with age. For all traits, among-individual variance increased as individuals got older. Our findings reveal seldom examined changes in variance components over the adult lifetime of wild individuals. Such changes will have important implications for the relationship between behavioral traits, life-histories, and fitness and the consequences of selection on wild individuals.

No MeSH data available.


Related in: MedlinePlus

Individual plots of activity change with age, with a linear trend line through each individual’s data points in grey and a population line in black. Activity showed an important degree of among-individual variation in intercepts, but not in slopes. There was a negative intercept–slope correlation (r = −0.491). Individuals increased their activity level with age (see Table 2 for full results).
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Figure 2: Individual plots of activity change with age, with a linear trend line through each individual’s data points in grey and a population line in black. Activity showed an important degree of among-individual variation in intercepts, but not in slopes. There was a negative intercept–slope correlation (r = −0.491). Individuals increased their activity level with age (see Table 2 for full results).

Mentions: There was among-individual variance in intercepts for activity (Figure 2), but little in slopes, and there was a significant, negative intercept–slope correlation. Crickets were more active when older and at hotter temperatures, and males were less active than females. Otherwise there was no effect of selective disappearance, mass, year, or habituation.


Dynamics of among-individual behavioral variation over adult lifespan in a wild insect.

Fisher DN, David M, Tregenza T, Rodríguez-Muñoz R - Behav. Ecol. (2015)

Individual plots of activity change with age, with a linear trend line through each individual’s data points in grey and a population line in black. Activity showed an important degree of among-individual variation in intercepts, but not in slopes. There was a negative intercept–slope correlation (r = −0.491). Individuals increased their activity level with age (see Table 2 for full results).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4495759&req=5

Figure 2: Individual plots of activity change with age, with a linear trend line through each individual’s data points in grey and a population line in black. Activity showed an important degree of among-individual variation in intercepts, but not in slopes. There was a negative intercept–slope correlation (r = −0.491). Individuals increased their activity level with age (see Table 2 for full results).
Mentions: There was among-individual variance in intercepts for activity (Figure 2), but little in slopes, and there was a significant, negative intercept–slope correlation. Crickets were more active when older and at hotter temperatures, and males were less active than females. Otherwise there was no effect of selective disappearance, mass, year, or habituation.

Bottom Line: All 4 traits showed among-individual variance in mean levels of expression across the adult lifespan, but no significant differences in how rapidly expression changed with age.Our findings reveal seldom examined changes in variance components over the adult lifetime of wild individuals.Such changes will have important implications for the relationship between behavioral traits, life-histories, and fitness and the consequences of selection on wild individuals.

View Article: PubMed Central - PubMed

Affiliation: Centre for Ecology and Conservation, University of Exeter , Treliever Road, Penryn TR109FE , UK and.

ABSTRACT

Investigating patterns of among and within-individual trait variation in populations is essential to understanding how selection shapes phenotypes. Behavior is often the most flexible aspect of the phenotype, and to understand how it is affected by selection, we need to examine how consistent individuals are. However, it is not well understood whether among-individual differences tend to remain consistent over lifetimes, or whether the behavior of individuals relative to one another varies over time. We examined the dynamics of 4 behavioral traits (tendency to leave a refuge, shyness, activity, and exploration) in a wild population of field crickets (Gryllus campestris). We tagged individuals and then temporarily removed them from their natural environment and tested them under laboratory conditions. All 4 traits showed among-individual variance in mean levels of expression across the adult lifespan, but no significant differences in how rapidly expression changed with age. For all traits, among-individual variance increased as individuals got older. Our findings reveal seldom examined changes in variance components over the adult lifetime of wild individuals. Such changes will have important implications for the relationship between behavioral traits, life-histories, and fitness and the consequences of selection on wild individuals.

No MeSH data available.


Related in: MedlinePlus