Hibernation is associated with increased survival and the evolution of slow life histories among mammals

Survival probability is predicted to underlie the evolution of life histories along a slow–fast continuum. Hibernation allows a diverse range of small mammals to exhibit seasonal dormancy, which might increase survival and consequently be associated with relatively slow life histories. We used phylogenetically informed GLS models to test for an effect of hibernation on seasonal and annual survival, and on key attributes of life histories among mammals. Monthly survival was in most cases higher during hibernation compared with the active season, probably because inactivity minimizes predation. Hibernators also have approximately 15 per cent higher annual survival than similar sized non-hibernating species. As predicted, we found an effect of hibernation on the relationships between life history attributes and body mass: small hibernating mammals generally have longer maximum life spans (50% greater for a 50 g species), reproduce at slower rates, mature at older ages and have longer generation times compared with similar-sized non-hibernators. In accordance with evolutionary theories, however, hibernating species do not have longer life spans than non-hibernators with similar survival rates, nor do they have lower reproductive rates than non-hibernators with similar maximum life spans. Thus, our combined results suggest that (i) hibernation is associated with high rates of overwinter and annual survival, and (ii) an increase in survival in hibernating species is linked with the coevolution of traits indicative of relatively slow life histories.

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Life histories, demographies and population dynamics of three sympatric chameleon species (Furcifer spp.) from western Madagascar

Amphibia-Reptilia ◽

10.1163/15685381-20181039 ◽

2019 ◽

Vol 40 (1) ◽

pp. 41-54 ◽

Cited By ~ 3

Author(s):

Falk Eckhardt ◽

Cornelia Kraus ◽

Peter M. Kappeler

Keyword(s):

Population Dynamics ◽

Life History ◽

Life Histories ◽

Survival Rates ◽

Seasonal Adjustment ◽

Annual Life Cycle ◽

Life History Data ◽

Annual Cohort ◽

History Of ◽

Reproductive Rates

Abstract The life histories and population dynamics of chameleons remain poorly known, most likely due to practical challenges related to their cryptic nature. However, several studies have indicated that some of these reptiles have unusually brief life histories. Specifically, one Madagascan chameleon (Furcifer labordi) was found to have an annual life cycle characterized by population-wide survival of the austral winter in the egg stage; a unique life history among tetrapods. In this study, we compare the life history of F. labordi with two locally sympatric congeners (F. cf. nicosiai and F. oustaleti) in Kirindy forest, western Madagascar, to determine how these species adjust their life histories to a highly seasonal and unpredictable climate. We found differences in lifespan, timing of hatching, growth rates, survival, reproductive rates, adult body size, and roosting heights among all three species. Moreover, two species exhibited relatively short lifespans: 6-9 months in F. labordi and 16-18 months in F. cf. nicosiai. In contrast, F. oustaleti is perennial and large-sized juveniles and adults aestivate during the dry season, but survival rates of adults seemed relatively low. Strikingly, the annual cohort of F. labordi was already adult when hatchlings of F. oustaleti and subsequently F. cf. nicosiai emerged. Our study suggests the co-existence of three different life histories with seasonal adjustment that might be related to the partitioning of overall food availability and contributes valuable life history data on enigmatic chameleon species.

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Inbreeding depression and floral type fitness differences in Viola canadensis (Violaceae), a species with chasmogamous and cleistogamous flowers

Canadian Journal of Botany ◽

10.1139/b00-115 ◽

2000 ◽

Vol 78 (11) ◽

pp. 1420-1429 ◽

Cited By ~ 12

Author(s):

Theresa M Culley

Keyword(s):

Inbreeding Depression ◽

Survival Rates ◽

Early Life History ◽

Flower Number ◽

Life History Stages ◽

The North ◽

History Of ◽

Vegetative Biomass ◽

Similar Survival ◽

Cross Type

Few studies of inbreeding depression have focused on species producing both showy, chasmogamous (CH) flowers and self-pollinated, cleistogamous (CL) flowers. The goals of this investigation were to measure the level of inbreeding depression in the North American violet, Viola canadensis L., and to determine if any fitness differences were linked to floral type (CH versus CL) rather than to cross type (self versus outcross). Hand pollinations were carried out to produce self- and outcross-pollinated CH progeny, and CL seeds were also collected. In a greenhouse, selfed and outcrossed CH flowers produced similar numbers of seeds, and both types of progeny had similar survival rates and comparable numbers of CH flowers, although outcrossed CH progeny had 14% greater vegetative biomass than selfed CH progeny. The level of inbreeding depression in V. canadensis was low, indicating that there may be few drawbacks to selfing in this species. A comparison of CL and self-pollinated CH progeny showed that, although there were differences in CH flower number, overall fitness differences were minimal. The similar performance of selfed (CL and CH) and outcrossed progeny in early life-history stages of V. canadensis suggests a history of inbreeding in the population.Key words: cleistogamy, inbreeding depression, outcrossing, selfing, Viola canadensis.

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Similar survival rates with endovascular, open aneurysm repair

Springer Healthcare News ◽

10.1007/s40014-012-1608-8 ◽

2012 ◽

Vol 1 (1) ◽

Keyword(s):

Survival Rates ◽

Similar Survival ◽

Aneurysm Repair

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A Primer of Life Histories

10.1093/oso/9780198839873.001.0001 ◽

2021 ◽

Author(s):

Jeffrey A. Hutchings

Keyword(s):

Life History ◽

Life Histories ◽

Life History Theory ◽

Life History Traits ◽

Reproductive Effort ◽

Effective Means ◽

Academic Experience ◽

Sustainable Exploitation ◽

Evolution Of Life ◽

Opportune Time

Life histories describe how genotypes schedule their reproductive effort throughout life in response to factors that affect their survival and fecundity. Life histories are solutions that selection has produced to solve the problem of how to persist in a given environment. These solutions differ tremendously within and among species. Some organisms mature within months of attaining life, others within decades; some produce few, large offspring as opposed to numerous, small offspring; some reproduce many times throughout their lives while others die after reproducing just once. The exponential pace of life-history research provides an opportune time to engage and re-engage new generations of students and researchers on the fundamentals and applications of life-history theory. Chapters 1 through 4 describe the fundamentals of life-history theory. Chapters 5 through 8 focus on the evolution of life-history traits. Chapters 9 and 10 summarize how life-history theory and prediction has been applied within the contexts of conservation and sustainable exploitation. This primer offers an effective means of rendering the topic accessible to readers from a broad range of academic experience and research expertise.

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Evolution of Life Histories

Population Biology ◽

10.1007/978-1-4757-2731-9_5 ◽

1997 ◽

pp. 107-116

Author(s):

Alan Hastings

Keyword(s):

Life Histories ◽

Evolution Of Life

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Experts correctly describe demography associated with historical decline of the endangered Indiana bat, but not recent period of stationarity

10.7287/peerj.preprints.2790v1 ◽

2017 ◽

Author(s):

Wayne Thogmartin ◽

Carol Sanders-Reed ◽

Jennifer Szymanski ◽

Lori Pruitt ◽

Michael Runge

Keyword(s):

Population Decline ◽

Survival Rates ◽

Clear Understanding ◽

Myotis Sodalis ◽

Indiana Bat ◽

White Nose Syndrome ◽

Demographic Behavior ◽

Pup Survival ◽

Survival And Reproduction ◽

Reproductive Rates

Demographic characteristics of bats are often insufficiently described for modeling populations. In data poor situations, experts are often relied upon for characterizing ecological systems. In concert with the development of a matrix model describing Indiana bat (Myotis sodalis) demography, we elicited estimates for parameterizing this model from 12 experts. We conducted this elicitation in two stages, requesting expert values for 12 demographic rates. These rates were adult and juvenile seasonal (winter, summer, fall) survival rates, pup survival in fall, and propensity and success at breeding. Experts were most in agreement about adult fall survival (3% Coefficient of Variation) and least in agreement about propensity of juveniles to breed (37% CV). The experts showed greater concordance for adult ( mean CV, adult = 6.2%) than for juvenile parameters ( mean CV, juvenile = 16.4%), and slightly more agreement for survival (mean CV, survival = 9.8%) compared to reproductive rates ( mean CV, reproduction = 15.1%). However, survival and reproduction were negatively and positively biased, respectively, relative to a stationary dynamic. Despite the species exhibiting near stationary dynamics for two decades prior to the onset of a potential extinction-causing agent, white-nose syndrome, expert estimates indicated a population decline of -11% per year (95% CI = -2%, -20%); quasi-extinction was predicted within a century ( mean = 61 years to QE, range = 32, 97) by 10 of the 12 experts. Were we to use these expert estimates in our modeling efforts, we would have errantly trained our models to a rapidly declining demography asymptomatic of recent demographic behavior. While experts are sometimes the only source of information, a clear understanding of the temporal and spatial context of the information being elicited is necessary to guard against wayward predictions.

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Survival of red-capped robins (Petroica goodenovii) in woodland remnants of central western New South Wales, Australia

Wildlife Research ◽

10.1071/wr01040 ◽

2001 ◽

Vol 28 (6) ◽

pp. 565 ◽

Cited By ~ 2

Author(s):

Richard E. Major ◽

Greg Gowing

Keyword(s):

Survival Rates ◽

Relative Survival ◽

Adult Mortality ◽

Annual Survival ◽

Survival Probabilities ◽

South Wales ◽

Winter Half ◽

Linear Habitat ◽

Significant Difference ◽

Summer Half

To determine relative survival rates of small birds occupying small, linear strips of woodland compared with large patches of woodland, marked populations of red-capped robins were monitored over a two-year period. In total, 196 male robins were banded with unique colour combinations in 10 woodland remnants and censused by song playback at half-yearly intervals. The Cormack–Jolly–Seber method was used to calculate half-yearly survival probabilities for birds in the two habitat configurations and the strongest model included separate survival parameters for summer (36.2% 5.1) and autumn (88.9% 13.5) half-years, but a constant recapture probability (50.5% 7.2). The inclusion of separate parameters for the large and linear habitat configurations reduced the strength of the model, indicating that there was no significant difference between the survival rates of birds occupying small, linear strips of woodland and birds occupying large patches of woodland. The mean annual survival, determined by multiplying the half-yearly survival probabilities, was 32%, which is low, compared with the annual survival of other Petroica robins. Although no banded birds were located away from the banding site, we suspect that much of the ‘mortality’ represented emigration during the summer half-year. Under this scenario a better estimate of annual survival (79%) might be achieved by extrapolation of survival over the winter half-year. This study provides no data to support the contention that adult mortality is higher in small, linear strips of habitat, although further data on the fate of birds that disappear from remnants is required before this is conclusive. In addition, to detect a 20% difference in survival using similar methods to the present study, with their accompanying sources of variation, at least 10 times the number of birds would need to be monitored. This might most effectively be done as a co-operative banding project.

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