Growth, mortality, and longevity of the Egyptian tortoise Testudo kleinmanni Lortet, 1883

2009 ◽  
Vol 55 (2) ◽  
pp. 133-147 ◽  
Author(s):  
Daniele Macale ◽  
Massimiliano Scalici ◽  
Alberto Venchi
Keyword(s):  
Reproductive Success ◽  
Growth Model ◽  
Reproductive Output ◽  
Growth Patterns ◽  
Male Reproductive Success ◽  
Population Status ◽  
Female Reproductive Success ◽  
Large Size ◽  
Threatened Taxa

Both demography and population regulation play an important role in the theory of sustainable exploitation and conservation of threatened taxa, such as terrestrial Chelonia. Here, we show and discuss some dynamic aspects of Testudo kleinmanni using modal progression analysis of length compositions. Although the Testudinata physiology is very different from that of fish, their growth model conforms to the Von Bertalanffy growth model. We observed a maximum of three age classes for both juveniles and females, and four classes for males. No appreciable between-sex differences were found in growth patterns, except for the diverse asymptotic length. Females should be subject to a strong sexual selection to quickly reach a large size in order to optimize lifetime reproductive output. The T. kleinmanni male size could be driven by predation escape and by easy accessibility to females, rather than by fighting for them. Thus, male reproductive success increases with the ability to fertilize females and female reproductive success increases with the ability to produce eggs, creating a large divergence in the context of selection between sexes. Different selective (synergetic or antagonistic) forces would appear to favor divergence in size between sexes. Additional properties found in the study regard the elevated mortality rate, probably also due to the human impact (poaching), and the relatively high longevity (26 and 22 years for females and males, respectively). Dynamics studies are useful for planning in situ activities of monitoring the population status, and could have a role in introducting programs and in control of reintroduced individuals during a restocking project.

scholarly journals Cohesion in male singing behavior predicts group reproductive output in a social songbird

2021 ◽  
Author(s):  
Ammon Perkes ◽  
Marc F Schmidt ◽  
H. Luke Anderson Anderson ◽  
Julie Gros-Louis ◽  
David White
Keyword(s):  
Reproductive Success ◽  
Social Interactions ◽  
Reproductive Output ◽  
Social Evolution ◽  
Group Structure ◽  
Social Systems ◽  
Male Reproductive Success ◽  
Group Level ◽  
Social Rules ◽  
Singing Behavior

All social groups require organization to function optimally. Group organization is often shaped by social 'rules', which function to manage conflict, discourage cheating, or promote cooperation. If social rules promote effective social living, then the ability to learn and follow these rules may be expected to influence individual and group-level fitness. However, such links can rarely be tested, due to the complexity of the factors mediating social systems and the difficulty of gathering data across multiple groups. Songbirds offer an opportunity to investigate the link between social rules and reproductive output because most of their social interactions are mediated by song, a well-studied and readily quantifiable behavior. Using observations from 19 groups of brown-headed cowbirds (Molothrus ater) studied across 15 years, we find evidence for a previously undocumented social rule: cohesive group transitions between dominance- and courtship-related singing. Comparing across groups, the degree of cohesion in male singing behavior predicts the reproductive output of their group. Experimental manipulation of group structure via the introduction of juvenile males to captive flocks reduced group cohesion and adult male reproductive success. Taken together, these results demonstrate that cohesion in group behavioral states can affect both individual and group-level reproductive success, suggesting that selection can act not only on individual-level traits, but also on an individual's ability and opportunity to participate effectively in organized social interactions. Social cohesion could therefore be an unappreciated force affecting social evolution in many diverse systems.

Reproductive success in wood bison (Bison bison athabascae) established using molecular techniques

2002 ◽  
Vol 80 (9) ◽  
pp. 1537-1548 ◽  
Author(s):  
Gregory A Wilson ◽  
Wes Olson ◽  
Curtis Strobeck
Keyword(s):  
Reproductive Success ◽  
National Park ◽  
Molecular Techniques ◽  
Bison Bison ◽  
Male Reproductive Success ◽  
Female Reproductive Success ◽  
Wood Bison ◽  
Low Levels ◽  
Elk Island National Park ◽  
Linear Regressions

In this study, we used 21 microsatellite loci to establish the reproductive success of the wood bison (Bison bison athabascae) population at Elk Island National Park, Alberta, Canada. Wood bison are considered threatened in Canada, and this population is currently used to found new populations. Despite the low levels of genetic variation in this population, we were able to establish paternity in 253 and maternity in 295 of the 317 calves born in Elk Island National Park over the 4-year study period. Roughly 40% of the mature males were reproductively successful each year. Mature males produced a mean of 3.8 offspring over the study period, with a range of 0–24. Each year, approximately 50–70% of the cows produced calves, with a mean of 2.7 over the study period. Multiple linear regressions were performed to determine the effects of age, mass, heterozygosity, prior success, and the year of conception on male and female reproductive success. Only mass and prior success were useful in predicting male reproductive success. Female reproductive success depended on age, mass, and prior success and was also affected by environmental differences between years. No evidence was found for inbreeding avoidance in wood bison.

scholarly journals A putative novel role for Eip74EF in male reproduction in promoting sperm elongation at the cost of male fecundity

2019 ◽  
Author(s):  
Sharif Chebbo ◽  
Sarah Josway ◽  
John M. Belote ◽  
Mollie K. Manier
Keyword(s):  
Reproductive Success ◽  
Oocyte Maturation ◽  
Male Reproduction ◽  
Male Reproductive Success ◽  
Sperm Length ◽  
Female Reproductive Success ◽  
Fitness Advantage ◽  
Males And Females ◽  
Opposing Effects ◽  
The Cost

ABSTRACTSpermatozoa are the most morphologically variable cell type, yet little is known about genes controlling natural variation in sperm shape. Drosophila fruit flies have the longest sperm known, which are evolving under postcopulatory sexual selection, driven by sperm competition and cryptic female choice. Long sperm outcompete short sperm but primarily when females have a long seminal receptacle (SR), the primary sperm storage organ. Thus, selection on sperm length is mediated by SR length, and the two traits are coevolving across the Drosophila lineage, driven by a genetic correlation and fitness advantage of long sperm and long SR genotypes in both males and females. Ecdysone induced protein 74EF (Eip74EF) is expressed during post-meiotic stages of spermatogenesis, when spermatid elongation occurs, and we found that it is rapidly evolving under positive selection in Drosophila. Hypomorphic knockout of the E74A isoform leads to shorter sperm but does not affect SR length, suggesting that E74A may be involved in promoting spermatid elongation but is not a genetic driver of male-female coevolution. We also found that E74A knockout has opposing effects on fecundity in males and females, with an increase in fecundity for males but a decrease in females, consistent with its documented role in oocyte maturation. Our results suggest a novel function of Eip74EF in spermatogenesis and demonstrates that this gene influences both male and female reproductive success. We speculate on possible roles for E74A in spermatogenesis and male reproductive success.RESEARCH HIGHLIGHTSEip74EF promotes oocyte maturation in Drosophila. We found evidence that it also promotes sperm elongation in males, but at a cost to male fecundity. Mutant males have shorter sperm but have higher reproductive success, while females have reduced fecundity.

The Largess of Motherhood

Anaconda ◽  
2020 ◽  
pp. 104-165
Author(s):  
Jesús A. Rivas
Keyword(s):  
Natural Selection ◽  
Young Adult ◽  
Reproductive Success ◽  
Reproductive Output ◽  
The Other ◽  
Reproductive Value ◽  
Lifetime Reproductive Success ◽  
Reproductive Decisions ◽  
Large Size ◽  
Breeding Resources

This chapter assesses the reasons and limitations for large size in female anacondas. Considering how large females are—nearly five times the size of males—it is obvious that the evolutionary pressures for large size act more strongly on females than males. One aspect in which natural selection definitely favors large size in females has to do with reproductive output. The larger a female is, the more babies can develop in her body and the larger the reproductive output. Reproductive value, or lifetime reproductive success, is the number of potential offspring that an individual can leave in the population over its lifetime. There are costs animals must face when they make reproductive decisions. Some of these costs are dependent on fecundity and some of them are not, such as the risk of being preyed upon during mating or pregnancy. A young adult female that has just reached maturity is under two opposite pressures: one is to breed right away and secure a few babies into the next generation, and the other is to skip reproduction, grow larger, and make more babies in a later year. A female that is going to breed faces another decision: how to invest her breeding resources. She can produce a large number of neonates of small size or a few offspring of large size.

High fishing intensity reduces females’ sperm reserve and brood fecundity in a eubrachyuran crab subject to sex- and size-biased harvest

2017 ◽  
Vol 74 (9) ◽  
pp. 2459-2469 ◽  
Author(s):  
Luis M Pardo ◽  
Marcela P Riveros ◽  
Juan Pablo Fuentes ◽  
Ramona Pinochet ◽  
Carla Cárdenas ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Reproductive Output ◽  
Sperm Storage ◽  
Female Size ◽  
Sperm Viability ◽  
Female Reproductive Success ◽  
Sperm Limitation ◽  
Chilean Populations

Abstract Size-selective male fisheries may result in sperm limitation whereby the number of sperm is insufficient to fertilize all oöcytes produced by females. In eubrachyuran crabs, females have seminal receptacles for sperm storage which may reduce the risk of sperm limitation over their lifetime. In this study on the commercially exploited eubrachyuran Metacarcinus edwardsii, we evaluate the sperm limitation hypothesis by measuring female reproductive success in five Chilean populations subjected to low or high fishing intensity. The quantity and viability of sperm stored by females was measured in each season and population, and related to resulting brood fecundity. Females’ sperm reserve was larger when fishing intensity was low than when it was high—paralleling previously demonstrated differences in males’ sperm reserve—and especially in the season before oviposition. Sperm viability was in general high (92%) and independent of fishing intensity. Mean brood fecundity adjusted to constant female size was about 60% greater under low compared with high fishing intensity. Thus, in M. edwardsii, population reproductive output could be depressed by male-biased fishing in spite of female sperm storage capability.

scholarly journals Quantitative trait locus mapping of fitness-related traits in Drosophila melanogaster

2001 ◽  
Vol 77 (1) ◽  
pp. 107-116 ◽  
Author(s):  
M. L. WAYNE ◽  
J. B. HACKETT ◽  
C. L. DILDA ◽  
S. V. NUZHDIN ◽  
E. G. PASYUKOVA ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Body Size ◽  
Reproductive Success ◽  
Quantitative Trait ◽  
Recombinant Inbred Lines ◽  
Male Reproductive Success ◽  
Female Reproductive Success ◽  
Mapping Procedure ◽  
Ovariole Number ◽  
Early Fecundity

We examined the genetic architecture of four fitness-related traits (reproductive success, ovariole number, body size and early fecundity) in a panel of 98 Oregon-R × 2b3 recombinant inbred lines (RILs). Highly significant genetic variation was observed in this population for female, but not male, reproductive success. The cross-sex genetic correlation for reproductive success was 0·20, which is not significantly different from zero. There was significant genetic variation segregating in this cross for ovariole number, but not for body size or early fecundity. The RILs were genotyped for cytological insertion sites of roo transposable elements, yielding 76 informative markers with an average spacing of 3·2 cM. Quantitative trait loci (QTL) affecting female reproductive success and ovariole number were mapped using a composite interval mapping procedure. QTL for female reproductive success were located at the tip of the X chromosome between markers at cytological locations 1B and 3E; and on the left arm of chromosome 2 in the 30D–38A cytological region. Ovariole number QTL mapped to cytological intervals 62D–69D and 98A–98E, both on the third chromosome. The regions harbouring QTL for female reproductive success and ovariole number were also identified as QTL for longevity in previous studies with these lines.

scholarly journals Postweaning maternal care increases male chimpanzee reproductive success

2020 ◽  
Vol 6 (38) ◽  
pp. eaaz5746
Author(s):  
Catherine Crockford ◽  
Liran Samuni ◽  
Linda Vigilant ◽  
Roman M. Wittig
Keyword(s):  
Reproductive Success ◽  
Parental Investment ◽  
Maternal Care ◽  
Parental Loss ◽  
Male Reproductive Success ◽  
Complex Societies ◽  
Successful Reproduction ◽  
Using Data

Humans are unusual among animals for continuing to provision and care for their offspring until adulthood. This “prolonged dependency” is considered key for the evolution of other notable human traits, such as large brains, complex societies, and extended postreproductive lifespans. Prolonged dependency must therefore have evolved under conditions in which reproductive success is gained with parental investment and diminished with early parental loss. We tested this idea using data from wild chimpanzees, which have similarly extended immature years as humans and prolonged mother-offspring associations. Males who lost their mothers after weaning but before maturity began reproducing later and had lower average reproductive success. Thus, persistent mother-immature son associations seem vital for enhancing male reproductive success, although mothers barely provision sons after weaning. We posit that these associations lead to social gains, crucial for successful reproduction in complex social societies, and offer insights into the evolution of prolonged dependency.

Significance of wounding to female reproductive success in Hawaiian monk seals (Monachus schauinslandi) at Laysan Island

1993 ◽  
Vol 71 (3) ◽  
pp. 469-474 ◽  
Author(s):  
Lisa M. Hiruki ◽  
Ian Stirling ◽  
William G. Gilmartin ◽  
Thea C. Johanos ◽  
Brenda L. Becker
Keyword(s):  
Reproductive Success ◽  
Adult Male ◽  
Reproductive Rate ◽  
Lactation Period ◽  
Female Reproductive Success ◽  
Monachus Schauinslandi ◽  
Lower Survival Rate ◽  
Adult Females ◽  
Pup Survival ◽  
Monk Seals

We studied reproductive rate, length of lactation period, pup survival, and mortality of injured and uninjured female Hawaiian monk seals (Monachus schauinslandi) on Laysan Island, northwestern Hawaiian Islands, in 1983 – 1989. The severity and timing of nonfatal injuries were influential in determining their effect on female reproductive success. There was a tendency towards a shorter mean lactation period and lower survival rate of pups for females with major injuries than for uninjured females. Females with minor injuries were similar to uninjured females in terms of reproductive rate, length of lactation, and pup survival. For females injured shortly before the birth of their pup or during lactation, pup survival was lower than for uninjured females, whereas for females injured during the year prior to pupping, measures of reproductive success were not significantly different from those for uninjured females. Immature (aged 4 – 8 years) females entering the reproductive population were injured by adult male seals significantly more often than females aged 0 – 3 years, but at a similar rate to adult females. The major effect of injuries on female reproductive success is an increase in female mortality: 87.5 % of the adult females (n = 16) that died on Laysan Island in 1983 – 1989 sustained injuries from adult male seals.

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