scholarly journals Life-history traits and the first demographic data of Iranian population of the West Asian Lemon-Yellow Tree Frog, Hyla savignyi (Audouin, 1827)

2021 ◽  
Vol 67 (3) ◽  
Author(s):  
Raziyeh Alaei ◽  
Alireza Pesarakloo ◽  
Masoumeh Najibzadeh ◽  
Sayed Jamal Mirkamali
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Demographic Data ◽  
Size Variation ◽  
Adult Survival ◽  
Lemon Yellow ◽  
Tree Frog ◽  
Size At Metamorphosis ◽  
Hyla Savignyi

The life-history of an organism consists of its lifetime pattern of growth, development, storage, age, and reproduction. In this study, some life-history traits of Hyla savignyi were studied in populations from different parts of Iran. The microscopic and macroscopic analysis showed that testicular activity in H. savignyi is potentially continuous, reaching its peak level in April. Metamorphosis was completed in approximately 102 days after egg deposition, and body size at metamorphosis was 10 mm. Significant sexual size dimorphism was present in all populations, and a larger female asymptotic body size was observed (43.07 mm for females vs 41.16 mm for males). The adult survival rate (S) and life expectancy (ESP) were the same for both sexes (S = 0.73 and ESP = 4.2 years). Age and body size were positively correlated with each other for both females and males. Maximum longevity was recorded to be six years in both females and males, and ages of sexual maturity were estimated to be two or three years in breeding individuals. The adult sample age ranged from two to six years (mean age of females: 4.40±0.68 years; males: 3.63±0.13 years). Our data confirm the general patterns of body size variation and mean age in anurans and show that females are larger than males and live longer.

Differential effects on life history traits and body size of two anuran species inhabiting an environment related to fluorite mine

2018 ◽  
Vol 93 ◽  
pp. 36-44 ◽  
Author(s):  
Manuel A. Otero ◽  
Favio E. Pollo ◽  
Pablo R. Grenat ◽  
Nancy E. Salas ◽  
Adolfo L. Martino
Keyword(s):  
Life History ◽  
Body Size ◽  
Life History Traits ◽  
Differential Effects ◽  
Anuran Species

scholarly journals Life history and habitat do not mediate temporal changes in body size due to climate warming in rodents

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9792
Author(s):  
Aluwani Nengovhela ◽  
Christiane Denys ◽  
Peter J. Taylor
Keyword(s):  
Life History ◽  
Body Size ◽  
Climate Warming ◽  
Life History Traits ◽  
Vegetation Type ◽  
Reproductive Rate ◽  
Temporal Changes ◽  
Temporal Response ◽  
Extrinsic Factors ◽  
African Species

Temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. Among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. Both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence of a significant temporal response of body size to climate warming but neither have been widely investigated. Using examples of rodents, we predicted that both life history traits and habitat might explain the probability of temporal response using two tests of this hypothesis. Firstly, taking advantage of new data from museum collections spanning the last 106 years, we investigated geographical and temporal variation in cranial size (a proxy for body size) in six African rodent species of two murid subfamilies (Murinae and Gerbillinae) of varying life history, degree of commensality, range size, and habitat. Two species, the commensal Mastomys natalensis, and the non-commensal Otomys unisulcatus showed significant temporal changes in body size, with the former increasing and the latter decreasing, in relation with climate warming. Commensalism could explain the increase in size with time due to steadily increasing food availability through increased agricultural production. Apart from this, we found no general life history or habitat predictors of a temporal response in African rodents. Secondly, in order to further test this hypothesis, we incorporated our data into a meta-analysis based on published literature on temporal responses in rodents, resulting in a combined dataset for 50 species from seven families worldwide; among these, 29 species showed no significant change, eight showed a significant increase in size, and 13 showed a decline in size. Using a binomial logistic regression model for these metadata, we found that none of our chosen life history or habitat predictors could significantly explain the probability of a temporal response to climate warming, reinforcing our conclusion based on the more detailed data from the six African species.

scholarly journals Density Dependence, Evolutionary Optimization, and the Diversification of Avian Life Histories

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Robert E. Ricklefs
Keyword(s):  
Life History ◽  
Life Table ◽  
Life Histories ◽  
Life History Traits ◽  
Evolutionary Ecology ◽  
Reproductive Rate ◽  
Empirical Modeling ◽  
Adult Survival ◽  
Life History Variation ◽  
Evolutionary Response

Abstract Although we have learned much about avian life histories during the 50 years since the seminal publications of David Lack, Alexander Skutch, and Reginald Moreau, we still do not have adequate explanations for some of the basic patterns of variation in life-history traits among birds. In part, this reflects two consequences of the predominance of evolutionary ecology thinking during the past three decades. First, by blurring the distinction between life-history traits and life-table variables, we have tended to divorce life histories from their environmental context, which forms the link between the life history and the life table. Second, by emphasizing constrained evolutionary responses to selective factors, we have set aside alternative explanations for observed correlations among life-history traits and life-table variables. Density-dependent feedback and independent evolutionary response to correlated aspects of the environment also may link traits through different mechanisms. Additionally, in some cases we have failed to evaluate quantitatively ideas that are compelling qualitatively, ignored or explained away relevant empirical data, and neglected logical implications of certain compelling ideas. Comparative analysis of avian life histories shows that species are distributed along a dominant slow-fast axis. Furthermore, among birds, annual reproductive rate and adult mortality are directly proportional to each other, requiring that pre-reproductive survival is approximately constant. This further implies that age at maturity increases dramatically with increasing adult survival rate. The significance of these correlations is obscure, particularly because survival and reproductive rates at each age include the effects of many life-history traits. For example, reproductive rate is determined by clutch size, nesting success, season length, and nest-cycle length, each of which represents the outcome of many different interactions of an individual's life-history traits with its environment. Resolution of the most basic issues raised by patterns of life histories clearly will require innovative empirical, modeling, and experimental approaches. However, the most fundamental change required at this time is a broadening of the evolutionary ecology paradigm to include a variety of alternative mechanisms for generating patterns of life-history variation.

Sexual dimorphism in body size and life‐history traits in a population ofTriturus alpestris alpestris

2004 ◽  
Vol 71 (sup2) ◽  
pp. 117-120 ◽  
Author(s):  
Elena Marzona ◽  
Daniele Seglie ◽  
Cristina Giacoma
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Life History Traits

scholarly journals Do females preferentially associate with males given a better start in life?

2012 ◽  
Vol 8 (3) ◽  
pp. 362-364 ◽  
Author(s):  
Andrew T. Kahn ◽  
Julianne D. Livingston ◽  
Michael D. Jennions
Keyword(s):  
Life History ◽  
Body Size ◽  
Food Intake ◽  
Compensatory Growth ◽  
Life History Traits ◽  
Adult Life ◽  
Gambusia Holbrooki ◽  
Developmental History ◽  
Restricted Diet ◽  
Adult Body

A poor start in life owing to a restricted diet can have readily detectable detrimental consequences for many adult life-history traits. However, some costs such as smaller adult body size are potentially eliminated when individuals modify their development. For example, male mosquitofish ( Gambusia holbrooki ) that have reduced early food intake undergo compensatory growth and delay maturation so that they eventually mature at the same size as males that develop normally. But do subtle effects of a poor start persist? Specifically, does a male's developmental history affect his subsequent attractiveness to females? Females prefer to associate with larger males but, controlling for body length, we show that females spent less time in association with males that underwent compensatory growth than with males that developed normally.

scholarly journals Determinants of life-history traits in a fish ectoparasite: a hierarchical analysis

Parasitology ◽  
2011 ◽  
Vol 138 (7) ◽  
pp. 848-857 ◽  
Author(s):  
G. LOOT ◽  
N. POULET ◽  
S. BROSSE ◽  
L. TUDESQUE ◽  
F. THOMAS ◽  
...  
Keyword(s):  
Life History ◽  
Body Size ◽  
Egg Size ◽  
Life History Traits ◽  
Abiotic Factors ◽  
Individual Characteristics ◽  
Trade Off ◽  
Individual Fitness ◽  
Parasite Number ◽  
Egg Number

SUMMARYObjective. Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We then determined the factors affecting the strength of the trade-off between egg number and egg size. Methods. To do so, we used 4-level (parasite, microhabitat, host and environment) hierarchical models coupled to a field database. Results. Variation in life-history traits was mostly due to individual characteristics measured at the parasite level. At the microhabitat level (fins of fish hosts), parasite number was positively related to body size, egg presence and egg number. Higher parasite number on fins was positively associated with individual parasite fitness. At the host level, host body size was positively related to the individual fitness of the parasite; parasites were bigger and more fecund on bigger hosts. In contrast, factors measured at the environmental level had a weak influence on life-history traits. Finally, a site-dependent trade-off between egg number and egg size existed in this population. Conclusion. Our study illustrates the importance of considering parasite life-history traits in a hierarchical framework to decipher complex links between biotic, abiotic factors and parasite life-history traits.

scholarly journals Corticosterone, testosterone and life-history strategies of birds

2010 ◽  
Vol 277 (1697) ◽  
pp. 3203-3212 ◽  
Author(s):  
Michaela Hau ◽  
Robert E. Ricklefs ◽  
Martin Wikelski ◽  
Kelly A. Lee ◽  
Jeffrey D. Brawn
Keyword(s):  
Life History ◽  
Body Mass ◽  
Breeding Season ◽  
Life History Traits ◽  
Survival Rates ◽  
Life History Strategies ◽  
Adult Survival ◽  
Tropical Species ◽  
Published Data ◽  
Season Length

Steroid hormones have similar functions across vertebrates, but circulating concentrations can vary dramatically among species. We examined the hypothesis that variation in titres of corticosterone (Cort) and testosterone (T) is related to life-history traits of avian species. We predicted that Cort would reach higher levels under stress in species with higher annual adult survival rates since Cort is thought to promote physiological and behavioural responses that reduce risk to the individual. Conversely, we predicted that peak T during the breeding season would be higher in short-lived species with high mating effort as this hormone is known to promote male fecundity traits. We quantified circulating hormone concentrations and key life-history traits (annual adult survival rate, breeding season length, body mass) in males of free-living bird species during the breeding season at a temperate site (northern USA) and a tropical site (central Panama). We analysed our original data by themselves, and also combined with published data on passerine birds to enhance sample size. In both approaches, variation in baseline Cort (Cort0) among species was inversely related to breeding season length and body mass. Stress-induced corticosterone (MaxCort) also varied inversely with body mass and, as predicted, also varied positively with annual adult survival rates. Furthermore, species from drier and colder environments exhibited lower MaxCort than mesic and tropical species; T was lowest in species from tropical environments. These findings suggest that Cort0, MaxCort and T modulate key vertebrate life-history responses to the environment, with Cort0 supporting energetically demanding processes, MaxCort promoting survival and T being related to mating success.

Relationship of larval density and heterozygosity to growth and survival of juvenile marbled salamanders (Ambystoma opacum)

1996 ◽  
Vol 74 (6) ◽  
pp. 1122-1129 ◽  
Author(s):  
Anne C. Chazal ◽  
John D. Krenz ◽  
David E. Scott
Keyword(s):  
Body Size ◽  
Larval Density ◽  
Larval Growth ◽  
Adult Survival ◽  
Growth And Survival ◽  
Ambystoma Opacum ◽  
Size At Metamorphosis ◽  
Body Sizes ◽  
Marbled Salamander ◽  
Relationship Of

Intraspecific competition and enzyme variability have been observed to influence the bioenergetics of many organisms. In amphibians, larval growth affects body size at metamorphosis, which in turn can lead to differences in adult survival and fecundity. We manipulated larval density in a population of the marbled salamander, Ambystoma opacum, and measured body size and enzyme variability in surviving newly metamorphosed juveniles. Crowded larval conditions resulted in lower survival and smaller body sizes at metamorphosis. Multilocus heterozygosity showed no relation to body size at high larval densities; however, at low larval densities relatively homozygous animals were larger. There was a significant interaction between heterozygosity and larval density in their effects on larval traits. Competition had a greater effect on body size at metamorphosis than did heterozygosity. Survival may be enhanced by heterozygosity but in a manner unrelated to body size.

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