scholarly journals Nest defence behavioural reaction norms: testing life-history and parental investment theory predictions

2019 ◽  
Vol 6 (4) ◽  
pp. 182180 ◽  
Author(s):  
Bert Thys ◽  
Yorick Lambreghts ◽  
Rianne Pinxten ◽  
Marcel Eens
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Parental Investment ◽  
Primary Source ◽  
Population Level ◽  
Path Model ◽  
Nest Defence ◽  
Reproductive Value ◽  
Stabilizing Selection ◽  
Trade Offs

Predation is the primary source of reproductive failure in many avian taxa and nest defence behaviour against predators is hence an important aspect of parental investment. Nest defence is a complex trait that might consistently differ among individuals (personality), while simultaneously vary within individuals (plasticity) according to the reproductive value of the offspring. Both complementary aspects of individual variation can influence fitness, but the causality of links with reproductive success remains poorly understood. We repeatedly tested free-living female great tits ( Parus major ) for nest defence (hissing) behaviour across the nesting cycle, by presenting them with a model predator. Hissing behaviour was highly repeatable but, despite population-level plasticity, we found no support for individual differences in plasticity. Path analysis revealed that repeatable differences in hissing behaviour had no direct effect on nest success or fledgling number. However, our best supported path-model showed that more fiercely hissing females laid smaller clutches, with clutch size in turn positively influencing fledgling number, suggesting that females are most likely facing a trade-off between investment in nest defence and reproduction. Strong stabilizing selection for optimal plasticity, in combination with life-history trade-offs, might explain the high repeatability of nest defence and its link with reproductive success.

Life histories of North American game birds: a reanalysis

1988 ◽  
Vol 66 (8) ◽  
pp. 1906-1912 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Life History ◽  
North American ◽  
Life Histories ◽  
Life History Traits ◽  
Reproductive Effort ◽  
Cost Of Reproduction ◽  
Reproductive Value ◽  
Trade Offs ◽  
Game Birds ◽  
The Cost

Recently, Zammuto (R. M. Zammuto. 1986. Can. J. Zool. 64: 2739–2749) suggested that North American game birds exhibited survival–fecundity trade-offs consistent with the "cost of reproduction" hypothesis. However, there were four serious problems with the data and the analyses that Zammuto used: (i) the species chosen for analysis ("game birds") showed little taxonomic or ecological uniformity, (ii) the measures of future reproductive value (maximum longevity) were severely biased by unequal sample sizes of band recoveries, (iii) the measures of current reproductive effort (clutch sizes) were inappropriate given that most of the birds analyzed produce self-feeding precocial offspring, and (iv) the statistical units used in the majority of analyses (species) were not statistically independent with respect to higher level taxonomy. After correcting these problems, I found little evidence of survival–fecundity trade-offs among precocial game birds, and I attribute most of the explainable variation in life-history traits of these birds to allometry, phylogeny, and geography.

Examining the link between religiousness and fitness in a behavioural ecological framework

2019 ◽  
Vol 52 (5) ◽  
pp. 756-767 ◽  
Author(s):  
Janko Međedović
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Parental Investment ◽  
Life History Theory ◽  
Community Sample ◽  
Future Research ◽  
Harsh Environment ◽  
Age At First Birth ◽  
First Birth ◽  
Number Of Children

AbstractIn recent years there have been attempts to explain religiousness from an evolutionary viewpoint. However, empirical data on this topic are still lacking. In the present study, the behavioural ecological theoretical framework was used to explore the relations between religiousness, harsh environment, fitness (reproductive success and parental investment) and fitness-related outcomes (age at first birth, desired number of children and the romantic relationship duration). The data were collected from 461 individuals from a community sample who were near the end of their reproductive phase (54% females, Mage = 51.75; SD = 6.56). Positive links between religiousness, harsh environment, fitness and fitness-related outcomes were expected, with the exception of age at first birth, for which a negative association was hypothesized. Hence, the main assumption of the study was that religiousness has some attributes of fast life-history phenotypes – that it emerges from a harsh environment and enables earlier reproduction. The study findings partially confirmed these hypotheses. Religiousness was positively related to environmental harshness but only on a zero-order level. Religious individuals had higher reproductive success (this association was especially pronounced in males) but religiousness did not show associations with parental investment. Religiousness was positively associated with desired number of children and negatively associated with age at first birth, although the latter association was only marginally significant in the multivariate analyses. Finally, path analysis showed that desired number of children and age at first birth completely mediated the relation between religiousness and reproductive success. The data confirmed the biologically adaptive function of religiousness in contemporary populations and found the mediating processes that facilitate fitness in religious individuals. Furthermore, the findings initiate a more complex view of religiousness in a life-history context which could be fruitful for future research: a proposal labelled as ‘ontogeny-dependent life-history theory of religiousness’.

Reproductive Effort and Costs

2021 ◽  
pp. 59-74
Author(s):  
Jeffrey A. Hutchings
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Total Energy ◽  
Reproductive Effort ◽  
Life History Evolution ◽  
Reproductive Costs ◽  
Positive Outcomes ◽  
Differential Allocation ◽  
Trade Offs ◽  
Potential Benefits

Predictions about life-history evolution are intellectually bereft without a consideration of trade-offs. Benefits derived from making one life-history ‘decision’ are made at a cost of not realizing potential benefits associated with alternative decisions. These trade-offs are the inevitable product of constraints, often driven by an individual’s differential allocation of fixed resources to reproduction versus survival or growth. These allocations prevent multiple positive outcomes from being simultaneously realized. Reproductive effort is the proportion of total energy or resources allocated to all elements of reproduction. Reproductive effort generates reproductive costs. Increases in current reproductive effort reduce future reproductive success by affecting survival, growth, and/or fecundity. The causal mechanisms of these costs can be energetic, ecological, behavioural, or genetic. Evidence for reproductive costs is widespread. Instances where the evidence of costs is equivocal are usually caused by using among-individual correlations to study what is a within-individual phenomenon.

scholarly journals Life history variation is maintained by fitness trade-offs and negative frequency-dependent selection

2018 ◽  
Vol 115 (17) ◽  
pp. 4441-4446 ◽  
Author(s):  
Mark R. Christie ◽  
Gordon G. McNickle ◽  
Rod A. French ◽  
Michael S. Blouin
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Life History Strategies ◽  
Lifetime Reproductive Success ◽  
Life History Variation ◽  
Additional Energy ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Trade Offs ◽  
Negative Frequency Dependent Selection

The maintenance of diverse life history strategies within and among species remains a fundamental question in ecology and evolutionary biology. By using a near-complete 16-year pedigree of 12,579 winter-run steelhead (Oncorhynchus mykiss) from the Hood River, Oregon, we examined the continued maintenance of two life history traits: the number of lifetime spawning events (semelparous vs. iteroparous) and age at first spawning (2–5 years). We found that repeat-spawning fish had more than 2.5 times the lifetime reproductive success of single-spawning fish. However, first-time repeat-spawning fish had significantly lower reproductive success than single-spawning fish of the same age, suggesting that repeat-spawning fish forego early reproduction to devote additional energy to continued survival. For single-spawning fish, we also found evidence for a fitness trade-off for age at spawning: older, larger males had higher reproductive success than younger, smaller males. For females, in contrast, we found that 3-year-old fish had the highest mean lifetime reproductive success despite the observation that 4- and 5-year-old fish were both longer and heavier. This phenomenon was explained by negative frequency-dependent selection: as 4- and 5-year-old fish decreased in frequency on the spawning grounds, their lifetime reproductive success became greater than that of the 3-year-old fish. Using a combination of mathematical and individual-based models parameterized with our empirical estimates, we demonstrate that both fitness trade-offs and negative frequency-dependent selection observed in the empirical data can theoretically maintain the diverse life history strategies found in this population.

scholarly journals Age-based soldier polyethism: old termite soldiers take more risks than young soldiers

2018 ◽  
Vol 14 (3) ◽  
pp. 20180025 ◽  
Author(s):  
Saki Yanagihara ◽  
Wataru Suehiro ◽  
Yuki Mitaka ◽  
Kenji Matsuura
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Life Expectancy ◽  
Task Allocation ◽  
Life History Theory ◽  
Nest Defence ◽  
Front Line ◽  
Age Dependent ◽  
Predatory Ants ◽  
Termite Soldiers

Who should take on risky tasks in an age-heterogeneous society? Life-history theory predicts that, in social insects, riskier tasks should be undertaken by sterile individuals with a shorter life expectancy. The loss of individuals with shorter life expectancy is less costly for colony reproductive success than the loss of individuals with longer life expectancy. Termite colonies have a sterile soldier caste, specialized defenders engaged in the most risky tasks. Here we show that termite soldiers exhibit age-dependent polyethism, as old soldiers are engaged in front-line defence more than young soldiers. Our nest defence experiment showed that old soldiers went to the front line and blocked the nest opening against approaching predatory ants more often than young soldiers. We also found that young soldiers were more biased toward choosing central nest defence as royal guards than old soldiers. These results demonstrate that termite soldiers have age-based task allocation, by which ageing predisposes soldiers to switch to more dangerous tasks. This age-dependent soldier task allocation increases the life expectancy of soldiers, allowing them to promote their lifetime contribution to colony reproductive success.

Adult lifetime reproductive value in fish depends on size and fecundity type

2016 ◽  
Vol 73 (9) ◽  
pp. 1405-1412 ◽  
Author(s):  
Stavroula Tsoukali ◽  
Karin H. Olsson ◽  
André W. Visser ◽  
Brian R. MacKenzie
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Life Stage ◽  
Adult Life ◽  
Early Life Stage ◽  
Reproductive Value ◽  
Trade Offs ◽  
Direct Proportionality ◽  
Proportionality Relationship

In a stable population, the adult lifetime reproductive value must be balanced against early life survival. Although delaying maturity may increase fecundity, it also reduces survival. Larger size at maturity therefore not only allows for higher fecundity, but requires it. Using simple arguments from life history, we derive a direct proportionality relationship between the adult lifetime reproductive value and weight at maturation and find that this relationship is consistent with empirical evidence from 28 stocks and species of bony fish from temperate–boreal environments. However, the expected proportionality falls off if mortality increases to include fishing. Furthermore, we find that the fecundity type (determinate or indeterminate) affects the predicted adult reproductive value, which is significantly (10-fold) higher for an indeterminate spawner than for a determinate spawner of the same weight. These differences may relate to trade-offs in the adult life history traits and (or) to seasonality in the spawning environment, with subsequent consequences for early life stage survivorship.

The cost of trying: weak interspecific correlations among life-history components in male ungulates

2012 ◽  
Vol 90 (9) ◽  
pp. 1072-1085 ◽  
Author(s):  
Marco Festa-Bianchet
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Life History Traits ◽  
Male Reproductive Success ◽  
Main Determinant ◽  
Young Males ◽  
Asymptotic Size ◽  
Trade Offs ◽  
The Cost ◽  
Slow Growing

Life-history trade-offs are well known in female mammals, but have seldom been quantified for males in polygynous species. I compared age-specific mass, weapon size, survival, and reproductive success of males in eight species of ungulates, and found weak interspecific correlations among life-history traits. Young males tended to have higher reproductive success in rapidly-growing than in slow-growing species, and in species where horns or antlers reached near-asymptotic size over the first few years of life. There was no clear interspecific trade-off between early reproduction and early survival. Reproductive senescence was evident in most species. Generation length, calculated as the mean age of fathers, was negatively correlated with the reproductive success of young males and positively with life expectancy of 3-year-olds, but not with early mortality. The main determinant of male reproductive success in polygynous ungulates is the ability to prevail against competing males. Consequently, the number and age structure of competitors should strongly affect an individual’s ability to reproduce, making classic trade-offs among life-history traits very context-dependent. Most fitness costs of reproduction in male ungulates likely arise from energy expenditure and injuries sustained while attempting to mate. Individual costs may be weakly correlated with fitness returns.

Life History Adaptation in Prey

2018 ◽  
pp. 323-346
Author(s):  
Gary A. Wellborn
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Reproductive Effort ◽  
Life History Evolution ◽  
Reproductive Value ◽  
Offspring Size ◽  
Selective Predation ◽  
Antipredator Defense ◽  
Trade Offs ◽  
History Evolution

Predation is a powerful agent of life history evolution in prey species, as demonstrated in diverse examples in crustaceans. Ubiquitous size- and age-selective predation mediates trade-offs among reproductive effort, survival, and growth, which cause evolution of constitutive and phenotypically plastic shifts in age and size at maturity. In accord with predictions of life history theory, comparative studies demonstrate that contrasting forms of selective predation generate divergent evolutionary changes in age- and size-specific allocation of reproductive effort within populations and species. Predation risk also influences egg and offspring size, and some crustaceans exhibit phenotypic plasticity in offspring size in response to chemical cues of predators. Because age-selective predation impacts the relative benefits of earlier versus later reproductive investment, predation may also shape senescence and life span of crustaceans. Additionally, individual differences in risk-taking behavior, sometimes termed “personalities,” have been examined in several crustaceans, and these may arise through among-individual variation in reproductive value. Finally, in some crustacean groups limb autotomy is a common, but costly, antipredator defense, and life history perspectives on autotomy suggest individuals may balance costs and benefits during predator encounters. Much of our understanding of predation’s role in life history evolution of prey derives from studies of crustaceans, and these organisms continue to be promising avenues to elucidate mechanisms of life history evolution.

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