A synthesis of senescence predictions for indeterminate growth, and support from multiple tests in wild lake trout

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2022, Volume and Issue: 289(1966)

Published: Jan. 5, 2022

Senescence—the deterioration of functionality with age—varies widely across taxa in pattern and rate. Insights into why how this variation occurs are hindered by the predominance laboratory-focused research on short-lived model species determinate growth. We synthesize evolutionary theories senescence, highlight key information gaps clarify predictions for low mortality variable degrees indeterminate Lake trout an ideal to evaluate wild. monitored individual males from two populations (1976–2017) longitudinally changes adult (actuarial senescence) body condition (proxy energy balance). A cross-sectional approach (2017) compared young (ages 4–10 years) old (18–37 adults (i) phenotypic performance condition, semen quality—which is related fertility under sperm competition (reproductive senescence)—and (ii) relative telomere length (potential proxy cellular senescence). Adult growth these particular constrained a simplified foodweb, our data support negligible senescence when maximum size only slightly larger than maturation size. Negative (aka reverse may occur other lake where diet shifts allow sizes greatly exceed

Language: Английский

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Physiological plasticity in elephants: highly dynamic glucocorticoids in African and Asian elephants

Conservation Physiology, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Abstract Slowly reproducing and long-lived terrestrial mammals are often more at risk from challenges that influence fitness survival. It is, therefore, important to understand how animals cope with such coping mechanisms translate over generations affect phenotypic plasticity. Rapidly escalating anthropogenic may further diminish an animal’s ability reinstate homeostasis. Research advance insights on elephant stress physiology has predominantly focused relative or comparative analyses of a major response marker, glucocorticoids (GCs), across different ecological, anthropogenic, reproductive contexts. This paper presents extensive review published findings Asian African elephants 1980 2023 (May) reveals responses, as measured by alterations in GCs sample matrices, highly dynamic vary within individuals exposed similar stimuli, not always predictable fashion. Such dynamicity physiological reactivity be mediated individual differences personality traits styles, ecological conditions, technical factors considered study designs. We describe probable causations under the ‘Physiological Dynamicity Model’, which considers context–experience–individuality effects. Highly variable adrenal responses plasticity potential survival consequences. also addresses significance cautious interpretations data context normal adaptive versus distress. emphasize need for long-term assessments incorporate multiple markers ‘stress’ ‘well-being’ decipher consequences elephants. Ultimately, we propose assessing GC current future is one most valuable informative conservation tools have guiding strategies.

Language: Английский

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Putative neural consequences of captivity for elephants and cetaceans

Reviews in the Neurosciences, Journal Year: 2021, Volume and Issue: 33(4), P. 439 - 465

Published: Sept. 16, 2021

Abstract The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, mammals. Although environment physical behavioral health has been well-documented, relatively little attention paid to brain itself. Here, we explore consequences living in environments, three levels: (1) effects environmental impoverishment/enrichment brain, emphasizing negative captive/impoverished environment; (2) stress an emphasis corticolimbic structures; (3) underpinnings stereotypies, often observed animals, underscoring dysregulation basal ganglia associated circuitry. To this end, provide substantive hypothesis about captivity brains large mammals (e.g., cetaceans elephants) how these are related documented evidence for compromised psychological well-being.

Language: Английский

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Genetic structure and diversity of semi-captive populations: the anomalous case of the Asian elephant

Conservation Genetics, Journal Year: 2024, Volume and Issue: 25(4), P. 973 - 984

Published: March 22, 2024

Abstract Wild species living in captivity are subject to loss of genetic diversity, inbreeding depression, and differentiation among populations. Only very few have been under human care for centuries but not selectively bred, free-ranging movements most the time, retain porous barriers gene flow between wild captive Such populations expected high levels diversity anthropogenic factors should result a limited from Asian elephants trained used by humans at least 4000 years as war animals, mounts kings draught animals. In Myanmar Laos, still being hauling timber forest while retaining traditional management practices including seasonal release, free mating movement. However, habitat fragmentation, isolation reduced flows threatening both semi-captive pools. We genotyped 167 Laos using panel 11 microsatellite loci estimate population structure. found that countries presented low degree inbreeding, if any. This agrees with level weak along geographical gradient southern northern no wild-caught captive-born The potential value conservation large has recognized community yet fully explore role could play maintaining flows.

Language: Английский

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Human–elephant coexistence challenges in Myanmar: An analysis of fatal elephant attacks on humans and elephant mortality

Journal for Nature Conservation, Journal Year: 2022, Volume and Issue: 69, P. 126260 - 126260

Published: Aug. 8, 2022

Language: Английский

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Nontraditional systems in aging research: an update

Cellular and Molecular Life Sciences, Journal Year: 2020, Volume and Issue: 78(4), P. 1275 - 1304

Published: Oct. 9, 2020

Research on the evolutionary and mechanistic aspects of aging longevity has a reductionist nature, as majority knowledge originates from experiments relatively small number systems species. Good examples are studies cellular, molecular, genetic attributes (senescence) that primarily based narrow group somatic cells, especially fibroblasts. and/or at organismal level is dominated, in turn, by Drosophila melanogaster, worms (Caenorhabditis elegans), yeast (Saccharomyces cerevisiae), higher organisms such mice humans. Other aging, though numerous, constitute minority. In this review, we collected discussed plethora up-to-date findings about longevity, sometimes even immortality several valuable but less frequently used systems, including bacteria (Caulobacter crescentus, Escherichia coli), invertebrates (Turritopsis dohrnii, Hydra sp., Arctica islandica), fishes (Nothobranchius Greenland shark), reptiles (giant tortoise), mammals (blind mole rats, naked bats, elephants, killer whale), 3D organoids, to prove they offer biogerontologists much more conventional tools. At same time, diversified gained owing research those species may help reconsider broader perspective, which should translate into better understanding tremendously complex clearly system-specific phenomenon.

Language: Английский

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Capture from the wild has long-term costs on reproductive success in Asian elephants

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2019, Volume and Issue: 286(1912), P. 20191584 - 20191584

Published: Oct. 9, 2019

Capturing wild animals is common for conservation, economic or research purposes. Understanding how capture itself affects lifetime fitness measures often difficult because and captive populations live in very different environments there a need long-term life-history data. Here, we show influences reproduction 2685 female Asian elephants (Elephas maximus) used the timber industry Myanmar. Wild-caught females demonstrated consistent reduction breeding success relative to captive-born females, with significantly lower probabilities, probabilities at peak reproductive ages later age of first reproduction. Furthermore, these negative effects lasted over decade, was significant influence on next generation: wild-caught had calves reduced survival 5. Our results suggest that has consequences reproduction, which important not only elephants, but also other species captivity.

Language: Английский

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Milk Composition of Asian Elephants (Elephas maximus) in a Natural Environment in Myanmar during Late Lactation

Animals, Journal Year: 2020, Volume and Issue: 10(4), P. 725 - 725

Published: April 22, 2020

The nutritional content of milk from free-living Asian elephants has not previously been reported, despite being vital for better management captive populations. This study analyzed both composition and consumed plant species managed in their natural environment Myanmar. Longitudinal samples (n = 36) were obtained during the wet dry season six mature females mid to late lactation 2016 2017. Milk averaged 82.44% water, with 17.56% total solids containing 5.23% protein, 15.10% fat, 0.87% ash, 0.18 µg/mL vitamin E. Solids protein increased month. Total was higher vs. season. Observed factors linked maternal (age, parity, size origin) calf traits (sex) had significant associations nutrient levels. Primary forages contained moderate fiber. Higher dietary (11-25%) compared (6-19%) may be observed. Our results call further field studies diet composition, over entire seasons/lactation periods, across traits, improve feeding management, an overall goal maximized health survival.

Language: Английский

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Assessing the Diversity of the Form of Age-Specific Changes in Adult Mortality from Captive Mammalian Populations

Diversity, Journal Year: 2020, Volume and Issue: 12(9), P. 354 - 354

Published: Sept. 15, 2020

Actuarial senescence (i.e., the age-specific increase in mortality rate) is pervasive across mammalian species, but our current understanding of diversity forms that actuarial displays species remains limited. Although several mathematical models have been proposed to model senescence, there still no consensus on which use, especially when comparing patterns among species. To fill this knowledge gap, we fitted and compared different using commonly used studies Gompertz, Weibull, logistic) 61 captive populations Bayesian Survival Trajectory Analysis (BaSTA) approach. For as much 79% a Gompertz with age was most parsimonious satisfactorily described shape changes adults. This highlights form mostly consistent follows rule some rare exceptions. The implications result are twofold. First, rate should be cross-species comparative analyses mammals, already done studies. Second, although accurately describes notable exceptions, factors causing deviation from an exponential during adult stage warrant further investigation.

Language: Английский

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Faecal Glucocorticoid Metabolites and H/L Ratio Are Related Markers of Stress in Semi-Captive Asian Timber Elephants

Animals, Journal Year: 2020, Volume and Issue: 10(1), P. 94 - 94

Published: Jan. 6, 2020

Animals are kept in captivity for various reasons, but species with a slower pace of life may adapt to captive environments less easily, leading welfare concerns and the need assess stress reliably order develop effective interventions. Our aim was semi-captive timber elephants from Myanmar by investigating relationship between two physiological markers commonly used as proxies welfare, faecal glucocorticoid metabolite concentrations (FGM) heterophil/lymphocyte ratios (H/L), link these measures changes body condition (determined weight). We further assessed how robustly performed animals different age or sex, ecological contexts. measured FGM H/L 2016 2018 316 samples 75 females 49 males ranging 4 68. found positive consistent FGMs Asian elephants, irrespective their age, context. results will help inform managers (semi-) about using ratio data blood smears on site potentially cheaper faster alternative determining than measuring laboratory.

Language: Английский

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