Heterogeneity in individual quality overrides costs of reproduction in female reindeer

Oecologia ◽  
2008 ◽  
Vol 156 (1) ◽  
pp. 237-247 ◽  
Author(s):  
Robert B. Weladji ◽  
Anne Loison ◽  
Jean-Michel Gaillard ◽  
Øystein Holand ◽  
Atle Mysterud ◽  
...  
Keyword(s):  
Individual Quality ◽  
Costs Of Reproduction

scholarly journals Consistent differences among individuals more influential than energetic trade-offs in life history variation in grey seals (Halichoerus grypus)

2021 ◽  
Author(s):  
Janelle Badger ◽  
W. Don Bowen ◽  
Nell den Heyer ◽  
Greg A. Breed
Keyword(s):  
Life History ◽  
Reproductive Performance ◽  
Adult Survival ◽  
Halichoerus Grypus ◽  
Individual Quality ◽  
Costs Of Reproduction ◽  
Life History Variation ◽  
Fitness Components ◽  
Age Class ◽  
Trade Offs

Life history variation is thought to be mainly a result of energetic trade-offs among fitness components; however, detecting these trade-offs in natural populations has yielded mixed results. Individual quality and environmental variation may mask expected relationships among fitness components because some higher quality individuals may be able to acquire more resources and invest more in all functions. Thus, life history variation may be more affected by variation in individual quality than varying strategies to resolve energetic trade-offs, e.g. costs of reproduction. Here, we investigated whether variation in female quality or costs of reproduction is a larger factor in shaping differences in life history trajectories by assessing the relationship between survival and individual reproductive performance using a 32-year longitudinal data set of repeated reproductive measurements from 273 individually marked, known-aged female grey seals (Halichoerus grypus) from the Sable Island breeding colony. We defined individual reproductive performance using two traits: reproductive frequency (a female's probability of breeding) and provisioning performance (provisions given to young measured by offspring mass), computed using mixed effects models separately for (1) all reproductive events, and (2) an age-class specific reproductive investment. Individual differences contributed a large portion of the variance in reproductive traits, with individuals displaying a range in individual reproductive frequencies from 0.45 to 0.94, and a range of average pup weaning masses from 34.9 kg to 61.8 kg across their lifetime. We used a Cormack-Jolly-Seber open-population model to estimate the effect of these reproductive performance traits on adult survival probability. Our approach estimated a positive relationship between reproductive performance and survival, where individuals that consistently invest well in their offspring survive longer. The best supported model estimated survival as a function of age-class specific provisioning performance, where late-life performance was quite variable and had the greatest impact on survival, possibly indicating individual variation in senescence. There was no evidence to support a trade-off in reproductive performance and survival at the individual level. These results suggest that in grey seals, individual quality is a stronger driver in life history variation than varying strategies to mitigate trade-offs among fitness components.

Costs of reproduction in female moose (Alces alces) as measured by means of phenotypic correlations

1998 ◽  
Vol 76 (1) ◽  
pp. 187-193 ◽  
Author(s):  
Håkan Sand
Keyword(s):  
Alces Alces ◽  
Positive Association ◽  
Body Growth ◽  
Individual Quality ◽  
Costs Of Reproduction ◽  
Annual Increase ◽  
Adult Females ◽  
Pregnancy And Lactation ◽  
Lactation Phase ◽  
Reproductive Category

The costs of pregnancy and lactation in terms of subsequent body growth and fecundity were studied by comparing different reproductive categories of Swedish female moose (Alces alces) during 1989-1992. Non-reproducing females and females that experienced gestation but not lactation were significantly heavier than females in the same reproductive category prior to reproduction. Production of one offspring and subsequent lactation during the summer and early autumn were also associated with an average annual increase in carcass mass, although this was less pronounced than in females that only experienced gestation. By contrast, production of two offspring and successful rearing of both to the autumn resulted, on average, in a reduction of carcass mass (7%) relative to that of females in the same reproductive category prior to reproduction. In female moose, while body growth was affected by the costs of lactation, future fecundity was not. Instead, future fecundity was related most strongly to the number of offspring produced during the current year. This positive association could not be attributed to variation in individual quality in terms of age or carcass mass. The ultimate consequences of reproduction in female moose seem to strongly influence the patterns of growth: adult females will alternate between gain and loss of body mass among years, depending on the number of offspring produced and successfully reared through the lactation phase.

Schedule for the Evaluation of Individual Quality of Life--Direct Weight

1997 ◽  
Author(s):  
John Browne ◽  
Ciaran A. O'Boyle ◽  
Hannah M. McGee ◽  
Nicholas J. McDonald ◽  
C. R. B. Joyce
Keyword(s):  
Quality Of Life ◽  
Individual Quality ◽  
Individual Quality Of Life

Inter-individual differences in the foraging behavior of breeding Adélie penguins are driven by individual quality and sex

2020 ◽  
Vol 636 ◽  
pp. 189-205
Author(s):  
A Lescroël ◽  
PO’B Lyver ◽  
D Jongsomjit ◽  
S Veloz ◽  
KM Dugger ◽  
...  
Keyword(s):  
Individual Differences ◽  
Foraging Behavior ◽  
Ross Sea ◽  
Individual Quality ◽  
High Quality ◽  
Breeding Experience ◽  
Age Related ◽  
Demographic Traits ◽  
Iteroparous Species ◽  
Adélie Penguins

Inter-individual differences in demographic traits of iteroparous species can arise through learning and maturation, as well as from permanent differences in individual ‘quality’ and sex-specific constraints. As the ability to acquire energy determines the resources an individual can allocate to reproduction and self-maintenance, foraging behavior is a key trait to study to better understand the mechanisms underlying these differences. So far, most seabird studies have focused on the effect of maturation and learning processes on foraging performance, while only a few have included measures of individual quality. Here, we investigated the effects of age, breeding experience, sex, and individual breeding quality on the foraging behavior and location of 83 known-age Adélie penguins at Cape Bird, Ross Sea, Antarctica. Over a 2 yr period, we showed that (1) high-quality birds dived deeper than lower quality ones, apparently catching a higher number of prey per dive and targeting different foraging locations; (2) females performed longer foraging trips and a higher number of dives compared to males; (3) there were no significant age-related differences in foraging behavior; and (4) breeding experience had a weak influence on foraging behavior. We suggest that high-quality individuals have higher physiological ability, enabling them to dive deeper and forage more effectively. Further inquiry should focus on determining the physiological differences among penguins of different quality.

A West Indian Midwife’s Tale

2017 ◽  
Author(s):  
Katherine Paugh
Keyword(s):  
Population Growth ◽  
Family Life ◽  
West Indian ◽  
Wage Labor ◽  
British Government ◽  
Costs Of Reproduction ◽  
Radical Reform ◽  
Registry System ◽  
Sugar Market ◽  
The Caribbean

The abolition of the Atlantic slave trade by the British government in 1807 was prompted by a confluence of geopolitical developments and concerns about reproduction. Shifts in the Atlantic world sugar economy had led to a glut on the British sugar market, and boosting production was therefore less of an economic concern than safeguarding reproduction. After 1807, demographic and financial calculations regarding the future of the plantation system intensified with the institution of a registry system designed to track slave populations. By 1823, British politicians, both abolitionists and West Indian planters, agreed to further radical reform: they hoped that encouraging Christian marital mores would finally bring about economically beneficial population growth. Acts legalizing Afro-Caribbean marriage were subsequently passed throughout the Caribbean. The outcome of this new emphasis on family life was ironic: as slavery gave way to wage labor, the costs of reproduction were shifted to Afro-Caribbean parents.

scholarly journals The physiological costs of reproduction in small mammals

2007 ◽  
Vol 363 (1490) ◽  
pp. 375-398 ◽  
Author(s):  
John R Speakman
Keyword(s):  
Life History ◽  
Small Mammals ◽  
Morphological Changes ◽  
Life History Evolution ◽  
Indirect Costs ◽  
Direct Costs ◽  
Costs Of Reproduction ◽  
Dominant Component ◽  
Trade Offs ◽  
Almost All

Life-history trade-offs between components of fitness arise because reproduction entails both gains and costs. Costs of reproduction can be divided into ecological and physiological costs. The latter have been rarely studied yet are probably a dominant component of the effect. A deeper understanding of life-history evolution will only come about once these physiological costs are better understood. Physiological costs may be direct or indirect. Direct costs include the energy and nutrient demands of the reproductive event, and the morphological changes that are necessary to facilitate achieving these demands. Indirect costs may be optional ‘compensatory costs’ whereby the animal chooses to reduce investment in some other aspect of its physiology to maximize the input of resource to reproduction. Such costs may be distinguished from consequential costs that are an inescapable consequence of the reproductive event. In small mammals, the direct costs of reproduction involve increased energy, protein and calcium demands during pregnancy, but most particularly during lactation. Organ remodelling is necessary to achieve the high demands of lactation and involves growth of the alimentary tract and associated organs such as the liver and pancreas. Compensatory indirect costs include reductions in thermogenesis, immune function and physical activity. Obligatory consequential costs include hyperthermia, bone loss, disruption of sleep patterns and oxidative stress. This is unlikely to be a complete list. Our knowledge of these physiological costs is currently at best described as rudimentary. For some, we do not even know whether they are compensatory or obligatory. For almost all of them, we have no idea of exact mechanisms or how these costs translate into fitness trade-offs.

Reproductive effort and costs of reproduction in female European ground squirrels

Oecologia ◽  
1999 ◽  
Vol 121 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Susanne Huber ◽  
Eva Millesi ◽  
Manfred Walzl ◽  
John Dittami ◽  
Walter Arnold
Keyword(s):  
Reproductive Effort ◽  
Ground Squirrels ◽  
Costs Of Reproduction
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