scholarly journals A trade-off between reproductive investment and maternal cerebellum size in a precocial bird

2016 ◽  
Vol 12 (12) ◽  
pp. 20160659 ◽  
Author(s):  
Christina Ebneter ◽  
Joel L. Pick ◽  
Barbara Tschirren
Keyword(s):  
Parental Investment ◽  
Life History Theory ◽  
Natural Populations ◽  
Reproductive Investment ◽  
Maternal Investment ◽  
Reproductive Behaviour ◽  
Trade Off ◽  
Precocial Bird ◽  
Animal Populations ◽  
Investment In Reproduction

Natural selection favours increased investment in reproduction, yet considerable variation in parental investment is observed in natural populations. Life-history theory predicts that this variation is maintained by a trade-off between the benefits of increased reproductive investment and its associated costs for the parents. The nature of these costs of reproduction, however, remains poorly understood. The brain is an energetically highly expensive organ and increased reproductive investment may, therefore, negatively affect brain maintenance. Using artificial selection lines for high and low prenatal maternal investment in a precocial bird, the Japanese quail ( Coturnix japonica ), we provide experimental evidence for this hypothesis by showing that increased prenatal provisioning negatively affects the size of a particular brain region of the mother, the cerebellum. Our finding suggests that cognitive demands may constrain the evolution of parental investment, and vice versa, contributing to the maintenance of variation in reproductive behaviour in animal populations.

Life History Strategies

2018 ◽  
Author(s):  
Iris Wang ◽  
Nicholas Michael Michalak ◽  
Joshua Ackerman
Keyword(s):  
Resource Allocation ◽  
Life History ◽  
Life History Theory ◽  
Species Differences ◽  
Reproductive Investment ◽  
Life History Strategies ◽  
Investment In Reproduction

Life history theory posits organisms face tradeoffs in how they allocate resources to reproduction, parenting, and growth. These patterns of resource allocation can be classified more broadly into life history strategies, which vary on a continuum from fast to slow. These distinctions can be applied to describe within species and between species differences. Slow strategies are marked by increased investment in growth, a delay in reproductive investment, and increased investment in parenting. In contrast, fast strategies are marked by early investment in reproduction at a cost of growth and a reduced investment in parenting in favor of further reproduction.

The shape of the trade-off function between reproduction and future performance in Plantago major and Plantago rugelii

2002 ◽  
Vol 80 (2) ◽  
pp. 140-150 ◽  
Author(s):  
Edward G Reekie ◽  
Sonya Budge ◽  
Jennifer L Baltzer
Keyword(s):  
Life History Theory ◽  
Reproductive Investment ◽  
Plantago Major ◽  
Trade Off ◽  
Reproductive Tissues ◽  
Future Performance ◽  
Resource Requirements ◽  
Survival And Reproduction ◽  
Sib Families ◽  
Low Levels

There is a paucity of data describing the nature of the trade-off function between reproduction and future performance. Most studies implicitly assume it is a linear function such that allocation of resources to reproduction results in a proportional decline in future survival and reproduction. We reanalyse data from a field experiment with half-sib families of Plantago major L. that suggests this relationship is in fact curvilinear. Low levels of reproductive investment had relatively little impact on future performance and higher levels of investment had a larger impact. To explain this curvilinear pattern, we conducted an experiment to examine the effect of incremental increases in reproductive investment on rates of resource uptake in P. major and Plantago rugelii Decne. Results suggest that, because of differences in the resource requirements of vegetative versus reproductive tissues, reproduction will have little effect on growth, providing that the limiting resources are required in greater quantities for vegetative as compared with reproductive tissues. These results are in accord with a curvilinear trade-off function between reproduction and future performance and provide an explanation for the maintenance of sexual reproduction in species where seed production may contribute minimally to fitness in the short term.Key words: reproductive cost, resource allocation, life-history theory, nitrogen uptake, reproductive photosynthesis, Plantago major, Plantago rugelii.

scholarly journals Glucocorticoids, state-dependent reproductive investment and success in the face of danger in a long-lived bird

2020 ◽  
Author(s):  
Kristina Noreikienė ◽  
Kim Jaatinen ◽  
Benjamin B. Steele ◽  
Markus Öst
Keyword(s):  
Predation Risk ◽  
Telomere Length ◽  
Clutch Size ◽  
Body Condition ◽  
Nest Predation ◽  
Hatching Success ◽  
Reproductive Investment ◽  
Trade Off ◽  
Relative Telomere Length ◽  
Future Reproduction

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

scholarly journals Estimation of Parameters of Deleterious Mutations in Partial Selfing or Partial Outcrossing Populations and in Nonequilibrium Populations

Genetics ◽  
2000 ◽  
Vol 154 (4) ◽  
pp. 1893-1906 ◽  
Author(s):  
Jian Li ◽  
Hong-Wen Deng
Keyword(s):  
Computer Simulations ◽  
Natural Populations ◽  
Deleterious Mutations ◽  
Selfing Rate ◽  
Estimation Of Parameters ◽  
Animal Populations ◽  
Rapid Pace ◽  
Dynamics Of Populations ◽  
Mutation And Selection

Abstract The Deng-Lynch method was developed to estimate the rate and effects of deleterious genomic mutations (DGM) in natural populations under the assumption that populations are either completely outcrossing or completely selfing and that populations are at mutation-selection (M-S) balance. However, in many plant and animal populations, selfing or outcrossing is often incomplete in that a proportion of populations undergo inbreeding while the rest are outcrossing. In addition, the degrees of deviation of populations from M-S balance are often not known. Through computer simulations, we investigated the robustness and the applicability of the Deng-Lynch method under different degrees of partial selfing or partial outcrossing and for nonequilibrium populations approaching M-S balance at different stages. The investigation was implemented under constant, variable, and epistatic mutation effects. We found that, generally, the estimation by the Deng-Lynch method is fairly robust if the selfing rate (S) is <0.10 in outcrossing populations and if S > 0.8 in selfing populations. The estimation may be unbiased under partial selfing with variable and epistatic mutation effects in predominantly outcrossing populations. The estimation is fairly robust in nonequilibrium populations at different stages approaching M-S balance. The dynamics of populations approaching M-S balance under various parameters are also studied. Under mutation and selection, populations approach balance at a rapid pace. Generally, it takes 400–2000 generations to reach M-S balance even when starting from homogeneous individuals free of DGM. Our investigation here provides a basis for characterizing DGM in partial selfing or outcrossing populations and for nonequilibrium populations.

scholarly journals Adult body growth and reproductive investment vary markedly within and across Atlantic and Pacific herring: a meta-analysis and review of 26 stocks

2021 ◽  
Author(s):  
Thassya C. dos Santos Schmidt ◽  
Doug E. Hay ◽  
Svein Sundby ◽  
Jennifer A. Devine ◽  
Guðmundur J. Óskarsson ◽  
...  
Keyword(s):  
Egg Size ◽  
Meta Analysis ◽  
Reproductive Investment ◽  
Body Growth ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Atlantic Herring ◽  
Additional Information ◽  
Trade Offs ◽  
Investment In Reproduction

AbstractLife-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.

The effects of capital on an income breeder: evidence from female Columbian ground squirrels

2005 ◽  
Vol 83 (4) ◽  
pp. 546-552 ◽  
Author(s):  
David R Broussard ◽  
F Stephen Dobson ◽  
J O Murie
Keyword(s):  
Path Analysis ◽  
Observational Data ◽  
Life Histories ◽  
Reproductive Investment ◽  
Ground Squirrels ◽  
Initial Capital ◽  
Spermophilus Columbianus ◽  
Live Trapping ◽  
Investment In Reproduction ◽  
Columbian Ground Squirrels

To maximize fitness, organisms must optimally allocate resources to reproduction, daily metabolic maintenance, and survival. We examined multiple years of live-trapping and observational data from a known-aged population of female Columbian ground squirrels, Spermophilus columbianus (Ord, 1815), to determine the influences of stored resources and daily resource income on the reproductive investments of females. We predicted that because yearling females were not fully grown structurally while producing their first litter, they would rely exclusively on income for reproduction, while reproductive investment in older females (≥2 years of age) would be influenced by both stored resources (capital) and daily income. Results from path analysis indicated that both yearlings and older females were income breeders. However, initial capital indirectly influenced investment in reproduction of yearling and older females. Females with the greatest initial capital maintained high body masses while investing relatively more income in reproduction. By considering influences of both capital and income, important relationships can be revealed between these resources and their influence on life histories.

Tales of lizard tails: effects of tail autotomy on subsequent survival and growth of free-ranging hatchling Uta stansburiana

1997 ◽  
Vol 75 (4) ◽  
pp. 542-548 ◽  
Author(s):  
P. H. Niewiarowski ◽  
J. D. Congdon ◽  
A. E. Dunham ◽  
L. J. Vitt ◽  
D. W. Tinkle
Keyword(s):  
Natural Populations ◽  
Reproductive Investment ◽  
Experimental Manipulation ◽  
Costs And Benefits ◽  
Growth And Survival ◽  
Large Sample ◽  
Uta Stansburiana ◽  
Tail Autotomy ◽  
Trade Offs ◽  
Free Ranging

Potential costs and benefits of tail autotomy in lizards have been inferred almost exclusively from experimental study in semi-natural enclosures and from indirect comparative evidence from natural populations. We present complementary evidence of the costs of tail autotomy to the lizard Uta stansburiana from detailed demographic study of a natural population. On initial capture, we broke the tails of a large sample of free-ranging hatchlings (560) and left the tails of another large sample (455) intact, and then followed subsequent hatchling growth and survival over a 3-year period. Surprisingly, in 1 out of the 3 years of study, survival of female hatchlings with broken tails exceeded that of female hatchlings with intact tails. Furthermore, no effects of tail loss on survivorship were detected for male hatchlings. However, in 2 years when recaptures were very frequent (1961, 1962), growth rates of hatchlings with broken tails were significantly slower than those of their counterparts with intact tails. We discuss our results in the broader context of estimating the relative costs and benefits of tail autotomy in natural populations, and suggest that long-term demographic studies will provide the best opportunity to assess realized fitness costs and benefits with minimum bias. We also describe how experimentally induced tail autotomy can be used as a technique to complement experimental manipulation of reproductive investment in the study of life-history trade-offs.

Effects of Natural Variation in Sex Ratio and Habitat Structure On Mate-Guarding Decisions in Amphipods (Crustacea)

Behaviour ◽  
1996 ◽  
Vol 133 (13-14) ◽  
pp. 985-996 ◽  
Author(s):  
Jaimie T.A. Dick ◽  
Robert W. Elwood
Keyword(s):  
Natural Populations ◽  
Mate Guarding ◽  
Reproductive Behaviour ◽  
Male Competition ◽  
Female Body Size ◽  
The Social ◽  
Size Assortment ◽  
Assortative Pairing ◽  
Study Species

AbstractWe employed field-based studies, with complementary laboratory-based studies, to investigate social and environmental influences on tactical mate-guarding decisions in amphipods (Crustacea). Firstly, we investigated variation in precopulatory mate-guarding duration in Cammarus duebeni celticus in relation to the social structure of natural populations. Variation in population density of up to two orders of magnitude had no effect on precopula duration, whereas guarding durations increased as the sex ratios of the populations became more male biased. That is, males have some ability to assess the probability of other males taking females into precopula and are prepared to guard for longer as this threat of male: male competition increases. A field demonstration of tactical shifts in reproductive behaviour in response to pertinent social conditions is thus provided. Secondly, the 'habitat segregation' hypothesis, which proposes that positive size-assortative pairing in amphipod populations arises due to variation in the use of micro-habitats, was tested in natural field populations and under laboratory conditions in Echinogammarus marinus. This was necessary in order to distinguish any purely environmental determinants of size-assortment from the role of active decisions by males concerning mate choice and male: male competition. The hypothesis was rejected on the grounds that size-assortative pairing arises under both heterogeneous and homogeneous environmental conditions. Further, in both study species, male and female body size were positively correlated with precopula duration. Thus, indirect competition for access to large, fecund females, based on the timing of male entry into precopula, together with direct aggression, provides the explanation for size-assortative pairing in amphipods.

scholarly journals Sex-biased immunity is driven by relative differences in reproductive investment

2014 ◽  
Vol 281 (1790) ◽  
pp. 20140333 ◽  
Author(s):  
Crystal M. Vincent ◽  
Darryl T. Gwynne
Keyword(s):  
Immune Response ◽  
Sex Differences ◽  
Immune System ◽  
Sexual Dimorphism ◽  
Parental Investment ◽  
Sex Role ◽  
Reproductive Investment ◽  
Paternal Investment ◽  
Sexual Competition ◽  
Relative Differences

Sex differences in immunity are often observed, with males generally having a weaker immune system than females. However, recent data in a sex-role-reversed species in which females compete to mate with males suggest that sexually competitive females have a weaker immune response. These findings support the hypothesis that sexual dimorphism in immunity has evolved in response to sex-specific fitness returns of investment in traits such as parental investment and longevity, but the scarcity of data in sex-reversed species prevents us from drawing general conclusions. Using an insect species in which males make a large but variable parental investment in their offspring, we use two indicators of immunocompetence to test the hypothesis that sex-biased immunity is determined by differences in parental investment. We found that when the value of paternal investment was experimentally increased, male immune investment became relatively greater than that of females. Thus, in this system, in which the direction of sexual competition is plastic, the direction of sex-biased immunity is also plastic and appears to track relative parental investment.

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