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

scholarly journals Alternative Concepts of Reproductive Effort, Costs of Reproduction, and Selection in Life-History Evolution

1983 ◽  
Vol 23 (1) ◽  
pp. 25-34 ◽  
Author(s):  
JUHA TUOMI ◽  
TUOMO HAKALA ◽  
ERKKI HAUKIOJA
Keyword(s):  
Life History ◽  
Reproductive Effort ◽  
Life History Evolution ◽  
Costs Of Reproduction ◽  
History Evolution

Differential Costs of Reproductive Effort for Male and Female Richardson's Ground Squirrels

Ecology ◽  
1990 ◽  
Vol 71 (3) ◽  
pp. 855-868 ◽  
Author(s):  
Gail R. Michener ◽  
L. Locklear
Keyword(s):  
Reproductive Effort ◽  
Ground Squirrels ◽  
Male And Female ◽  
Differential Costs

Timing is the only thing: reproduction in female yellow ground squirrels (Spermophilus fulvus)

2014 ◽  
Vol 92 (8) ◽  
pp. 737-747 ◽  
Author(s):  
N.A. Vasilieva ◽  
A.V. Tchabovsky
Keyword(s):  
Litter Size ◽  
Body Condition ◽  
Reproductive Effort ◽  
Individual Characteristics ◽  
Ground Squirrels ◽  
Offspring Survival ◽  
Litter Mass ◽  
Individual Offspring ◽  
Female Survival ◽  
Spermophilus Fulvus

Based on 4-year field observations of yellow ground squirrels (Spermophilus fulvus (Lichtenstein, 1823)), we determined whether female reproductive effort, annual reproductive success, and survival were dependent on age, body condition, time of emergence from hibernation, and previous reproduction. The probability of weaning a litter did not vary with female age, body condition, time of emergence, or previous reproduction. Litter size, litter mass, and offspring survival did not vary with age, whereas individual offspring mass was lower in yearlings than in older females. Body condition upon emergence had no effect on litter size, litter mass, offspring mass, and survival. Reproduction did not influence female survival, physical condition upon emergence next spring, or subsequent reproductive efforts. The only factor that affected the extent of reproductive effort and offspring survival was the date of emergence: the later a female emerged, the lower the total and mean offspring mass, and fewer offspring survived. The modulation of reproduction in female S. fulvus by only the timing of vernal emergence and independent of other individual characteristics can be explained by the high costs of missed reproductive opportunity because of short longevity combined with low costs of reproduction when resources are abundant enough to meet both somatic and reproductive needs.

Growth and its relationship to the initial annual cycle of the golden-mantled ground squirrel, Spermophilus lateralis

1981 ◽  
Vol 59 (6) ◽  
pp. 865-871 ◽  
Author(s):  
John A. Phillips
Keyword(s):  
Litter Size ◽  
Annual Cycle ◽  
Ground Squirrel ◽  
Growth And Development ◽  
Reproductive Effort ◽  
Ground Squirrels ◽  
Active Season ◽  
Spermophilus Lateralis ◽  
Significant Difference ◽  
Two Populations

Thirty-eight litters of golden-mantled ground squirrels (Spermophilus lateralis), from two populations that experienced different lengths of active season, were born and raised in the laboratory. Growth and development in young were inversely related to litter size. Offspring from smaller litters were both able to attain their prehibernation peak of body mass sooner and hibernate after fewer days of homeothermy than squirrels from larger litters. Young that remained homeothermic throughout the initial overwintering period were always from large litters and among the slowest growing littermates. Fecundity was lower in females from the temporally compressed environment. There was no significant difference between populations in the nutrition provided by mothers to their litters. The results suggest that reproductive effort is more conservative in populations of ground squirrels that experience short seasons of activity, yet this conservatism allows the offspring of those populations to reach independence and attain the prehibernation state of preparedness at an earlier age than their counterparts from populations of more moderate climates.

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 Androgen Elevation Accelerates Reproductive Senescence in Three-Spined Stickleback

2021 ◽  
Vol 9 ◽  
Author(s):  
Mirre J. P. Simons ◽  
Marion Sebire ◽  
Simon Verhulst ◽  
Ton G. G. Groothuis
Keyword(s):  
Vitamin E ◽  
Reproductive Effort ◽  
Negative Relationship ◽  
Life History Evolution ◽  
Reproductive Capacity ◽  
Costs Of Reproduction ◽  
Iris Color ◽  
Future Reproduction ◽  
Reproductive Activities ◽  
Breeding Coloration

Costs of reproduction shape the life-history evolution of investment in current and future reproduction and thereby aging. Androgens have been proposed to regulate the physiology governing these investments. Furthermore, androgens are hypothesized to play a central role in carotenoid-dependent sexual signaling, regulating how much carotenoids are diverted to ornamentation and away from somatic maintenance, increasing oxidative stress, and accelerating aging. We investigated these relationships in male three-spined stickleback in which we elevated 11-ketotestosterone and supplied vitamin E, an antioxidant, in a 2 × 2 design. Androgen elevation shortened the time stickleback maintained reproductive activities. We suspect that this effect is caused by 11-ketotestosterone stimulating investment in current reproduction, but we detected no evidence for this in our measurements of reproductive effort: nest building, body composition, and breeding coloration. Carotenoid-dependent coloration was even slightly decreased by 11-ketotestosterone elevation and was left unaffected by vitamin E. Red coloration correlated with life expectancy and reproductive capacity in a quadratic manner, suggesting overinvestment of the individuals exhibiting the reddest bellies. In contrast, blue iris color showed a negative relationship with survival, suggesting physiological costs of producing this aspect of nuptial coloration. In conclusion, our results support the hypothesis that androgens regulate investment in current versus future reproduction, yet the precise mechanisms remain elusive. The quadratic relationships between sexual signal expression and aspects of quality have wider consequences for how we view sexual selection on ornamentation and its relationship with aging.

Reproductive effort during gestation and lactation by Richardson's ground squirrels

Oecologia ◽  
1989 ◽  
Vol 78 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Gail R. Michener
Keyword(s):  
Reproductive Effort ◽  
Ground Squirrels

scholarly journals Reproductive effort and costs of reproduction do not explain female-biased sex ratios in the moss Pseudocalliergon trifarium (Amblystegiaceae)

2006 ◽  
Vol 93 (9) ◽  
pp. 1313-1319 ◽  
Author(s):  
I. Bisang ◽  
J. Ehrlen ◽  
L. Hedenas
Keyword(s):  
Reproductive Effort ◽  
Sex Ratios ◽  
Costs Of Reproduction

scholarly journals The costs of reproduction in female columbian ground squirrels

Oecologia ◽  
1987 ◽  
Vol 73 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. O. Murie ◽  
F. S. Dobson
Keyword(s):  
Ground Squirrels ◽  
Costs Of Reproduction ◽  
Columbian Ground Squirrels
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