Older conservatives: reproduction in female Alpine chamois (Rupicapra rupicapra) is increasingly risk-averse with age

2016 ◽  
Vol 94 (5) ◽  
pp. 311-321 ◽  
Author(s):  
A. Morin ◽  
M. Rughetti ◽  
S. Rioux-Paquette ◽  
M. Festa-Bianchet
Keyword(s):  
Reproductive Success ◽  
Reproductive Effort ◽  
Risk Averse ◽  
Costs Of Reproduction ◽  
Rupicapra Rupicapra ◽  
Terminal Investment ◽  
Age Dependent ◽  
Alpine Chamois ◽  
Old Females ◽  
Investment Hypothesis

In long-lived mammals, costs of reproduction may vary with age. The terminal investment hypothesis predicts greater reproductive effort as females approach the end of their life expectancy. We monitored 97 individually marked female Alpine chamois (Rupicapra rupicapra (L., 1758)) between 2007 and 2013 to determine how age-specific reproduction affected body mass and subsequent reproductive success. We captured and weighed females between April and August and monitored reproductive success from April to October through mother–kid associations. Reproductive success was strongly age-dependent and peaked at 70% for prime-aged females (4–7 years). Reproductive senescence began at 8 years, earlier than reported by other studies of ungulates. There was no clear evidence of reproductive costs in any age class. Reproductive success was very heterogeneous for old females, suggesting variability in the onset of senescence. Old females were less likely to reproduce in poor years despite being heavier than prime-aged females, suggesting reproductive restraint in late life rather than terminal investment. Female mass remained stable from May to August with no effect of lactation. Our results suggest that chamois reproductive strategy becomes increasingly conservative with age, resulting in no detectable costs of reproduction.

scholarly journals Senescent birds redouble reproductive effort when ill: confirmation of the terminal investment hypothesis

2006 ◽  
Vol 273 (1593) ◽  
pp. 1443-1448 ◽  
Author(s):  
Alberto Velando ◽  
Hugh Drummond ◽  
Roxana Torres
Keyword(s):  
Reproductive Success ◽  
Reproductive Effort ◽  
Initial Increase ◽  
Male Reproductive Success ◽  
Age Classes ◽  
Theoretical Idea ◽  
Sula Nebouxii ◽  
Terminal Investment ◽  
Survival And Reproduction ◽  
Investment Hypothesis

This study reports an experimental confirmation of the terminal investment hypothesis, a longstanding theoretical idea that animals should increase their reproductive effort as they age and their prospects for survival and reproduction decline. Previous correlational and experimental attempts to test this hypothesis have yielded contradictory results. In the blue-footed booby, Sula nebouxii , a long-lived bird, after initial increase, male reproductive success declines progressively with age. Before laying, males of two age classes were challenged with lipopolysaccharide to elicit an immune response, which induced symptoms of declining survival prospects. Reproductive success of immune-challenged mature males fell, while that of immune-challenged old males showed a 98% increase. These results demonstrate that senescent males with poor reproductive prospects increase their effort when those prospects are threatened, whereas younger males with good reproductive prospects do not.

scholarly journals Amphibians with infectious disease increase their reproductive effort: evidence for the terminal investment hypothesis

Open Biology ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 150251 ◽  
Author(s):  
Laura A. Brannelly ◽  
Rebecca Webb ◽  
Lee F. Skerratt ◽  
Lee Berger
Keyword(s):  
Disease Resistance ◽  
Reproductive Effort ◽  
Batrachochytrium Dendrobatidis ◽  
Population Level ◽  
Life History Trait ◽  
Terminal Investment ◽  
Frog Species ◽  
Selection For ◽  
Declining Species ◽  
Investment Hypothesis

Mounting an immune response to fight disease is costly for an organism and can reduce investment in another life-history trait, such as reproduction. The terminal investment hypothesis predicts that an organism will increase reproductive effort when threatened by disease. The reproductive fitness of amphibians infected with the deadly fungal pathogen Batrachochytrium dendrobatidis ( Bd ) is largely unknown. In this study, we explored gametogenesis in two endangered and susceptible frog species, Pseudophryne corroboree and Litoria verreauxii alpina. Gametogenesis, both oogenesis and spermatogenesis, increased when animals were experimentally infected with Bd . In P. corroboree , infected males have thicker germinal epithelium, and a larger proportion of spermatocytes. In L. v. alpina , infected males had more spermatic cell bundles in total, and a larger proportion of spermatozoa bundles. In female L. v. alpina , ovaries and oviducts were larger in infected animals, and there were more cells present within the ovaries. Terminal investment has consequences for the evolution of disease resistance in declining species. If infected animals are increasing reproductive efforts and producing more offspring before succumbing to disease, it is possible that population-level selection for disease resistance will be minimized.

scholarly journals Ant queens increase their reproductive efforts after pathogen infection

2017 ◽  
Vol 4 (7) ◽  
pp. 170547 ◽  
Author(s):  
Julia Giehr ◽  
Anna V. Grasse ◽  
Sylvia Cremer ◽  
Jürgen Heinze ◽  
Alexandra Schrempf
Keyword(s):  
Social Insect ◽  
Reproductive Effort ◽  
Reproductive Rate ◽  
Egg Laying ◽  
Reproductive Value ◽  
Reproductive Senescence ◽  
Terminal Investment ◽  
Investment In Reproduction ◽  
First Time ◽  
Investment Hypothesis

Infections with potentially lethal pathogens may negatively affect an individual's lifespan and decrease its reproductive value. The terminal investment hypothesis predicts that individuals faced with a reduced survival should invest more into reproduction instead of maintenance and growth. Several studies suggest that individuals are indeed able to estimate their body condition and to increase their reproductive effort with approaching death, while other studies gave ambiguous results. We investigate whether queens of a perennial social insect (ant) are able to boost their reproduction following infection with an obligate killing pathogen. Social insect queens are special with regard to reproduction and aging, as they outlive conspecific non-reproductive workers. Moreover, in the ant Cardiocondyla obscurior , fecundity increases with queen age. However, it remained unclear whether this reflects negative reproductive senescence or terminal investment in response to approaching death. Here, we test whether queens of C. obscurior react to infection with the entomopathogenic fungus Metarhizium brunneum by an increased egg-laying rate. We show that a fungal infection triggers a reinforced investment in reproduction in queens. This adjustment of the reproductive rate by ant queens is consistent with predictions of the terminal investment hypothesis and is reported for the first time in a social insect.

Dermatophilosis of Alpine Chamois (Rupicapra rupicapra) in Italy

2002 ◽  
Vol 144 (3) ◽  
pp. 131-136 ◽  
Author(s):  
D. De Meneghi ◽  
E. Ferroglio ◽  
E. Bollo ◽  
L. Leon Vizcaino ◽  
A. Moresco ◽  
...  
Keyword(s):  
Rupicapra Rupicapra ◽  
Alpine Chamois

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

Energy Expenditure in Reproductive Effort of Male and Female Killdeer (Charadrius vociferus)

The Auk ◽  
1988 ◽  
Vol 105 (3) ◽  
pp. 553-564 ◽  
Author(s):  
Dianne H. Brunton
Keyword(s):  
Reproductive Success ◽  
Energy Expenditure ◽  
Parental Care ◽  
Breeding Season ◽  
Reproductive Effort ◽  
Mating Effort ◽  
Parental Effort ◽  
Nest Failure ◽  
Male And Female ◽  
Charadrius Vociferus

Abstract The reproductive investment strategies of the sexes during the breeding season are detailed for Killdeer (Charadrius vociferus), a monogamous plover. I measured the energy investments of the sexes in reproductive, mating, and parental effort. As predicted, males expend more mating effort than females; however, the sexes expend equal amounts of parental effort. Total energy expenditure in reproductive effort (mating and parental effort) during a successful nesting attempt was also equal for the sexes. However, early parental effort expenditures by females, early mating effort expenditures by males, and high rates of nest failure combine to result in female reproductive energy expenditures being significantly higher over the breeding season. This suggests that energy expenditure alone is not adequate for accurate comparisons of the relative investments of the sexes. Studies investigating male and female investments need to consider the degree and pattern of nest failures along with patterns of energy expenditure. The advantages to male and female Killdeer of sharing parental care is demonstrated using adult removal experiments. In general, a deserted parent expends more energy in parental effort than a bi-parental parent and has significantly lower reproductive success. However, males are able to hatch chicks, whereas females lose or abandon their nests within a few days of mate removal. Thus, monogamy in Killdeer appears to result from high nest failure rates, the necessity of two parents for any reproductive success, and the generalizable nature of Killdeer parental care.

Ecological drivers of group size in female Alpine chamois, Rupicapra rupicapra

Mammalia ◽  
2015 ◽  
Vol 79 (4) ◽  
Author(s):  
Roberta Chirichella ◽  
Andrea Mustoni ◽  
Marco Apollonio
Keyword(s):  
Predation Risk ◽  
Energy Intake ◽  
Group Size ◽  
Food Availability ◽  
Herd Size ◽  
Rupicapra Rupicapra ◽  
Trade Off ◽  
Mammalian Herbivores ◽  
Alpine Chamois

AbstractIn large mammalian herbivores, an increase in herd size not only reduces predation risk but also energy intake. As a consequence, the size of the groups made up by herbivores is often assumed to be the outcome of a trade-off depending on local predation risk and food availability. We studied Alpine chamois (

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