Photoperiodic regulation of life-history traits before and after eclosion: Egg-to-adult development time, juvenile body mass and reproductive diapause in Drosophila montana

AbstractLife history, brain size and energy expenditure scale with body mass in mammals but there is little conclusive evidence for a correlated evolution between life history and energy expenditure (either basal/resting or daily) independent of body mass. We addressed this question by examining the relationship between primate free-living daily energy expenditure (DEE) measured by doubly labeled water method (n = 18 species), life history variables (maximum lifespan, gestation and lactation duration, interbirth interval, litter mass, age at first reproduction), resting metabolic rate (RMR) and brain size. We also analyzed whether the hypometabolic primates of Madagascar (lemurs) make distinct energy allocation tradeoffs compared to other primates (monkeys and apes) with different life history traits and ecological constraints. None of the life-history traits correlated with DEE after controlling for body mass and phylogeny. In contrast, a regression model showed that DEE increased with increasing RMR and decreasing reproductive output (i.e., litter mass/interbirth interval) independent of body mass. Despite their low RMR and smaller brains, lemurs had an average DEE remarkably similar to that of haplorhines. The data suggest that lemurs have evolved energy strategies that maximize energy investment to survive in the unusually harsh and unpredictable environments of Madagascar at the expense of reproduction.

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The Scarcity of Specific Nutrients in Wild Bee Larval Food Negatively Influences Certain Life History Traits

Biology ◽

10.3390/biology9120462 ◽

2020 ◽

Vol 9 (12) ◽

pp. 462

Author(s):

Zuzanna M. Filipiak ◽

Michał Filipiak

Keyword(s):

Life History ◽

Body Mass ◽

Behavioral Ecology ◽

Life History Traits ◽

Chemical Elements ◽

Nutritional Ecology ◽

Larval Food ◽

Male Mortality ◽

Wild Bee ◽

The Impact

Bee nutrition studies have focused on food quantity rather than quality, and on details of bee biology rather than on the functioning of bees in ecosystems. Ecological stoichiometry has been proposed for studies on bee nutritional ecology as an ecosystem-oriented approach complementary to traditional approaches. It uses atomic ratios of chemical elements in foods and organisms as metrics to ask ecological questions. However, information is needed on the fitness effects of nutritional mismatches between bee demand and the supply of specific elements in food. We performed the first laboratory feeding experiment on the wild bee Osmia bicornis, investigating the impact of Na, K, and Zn scarcity in larval food on fitness-related life history traits (mortality, cocoon development, and imago body mass). We showed that bee fitness is shaped by chemical element availability in larval food; this effect may be sex-specific, where Na might influence female body mass, while Zn influences male mortality and body mass, and the trade-off between K allocation in cocoons and adults may influence cocoon and body development. These results elucidate the nutritional mechanisms underlying the nutritional ecology, behavioral ecology, and population functioning of bees within the context of nutrient cycling in the food web.

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Costs and benefits of post-weaning associations in mountain goats

Behaviour ◽

10.1163/1568539x-00003490 ◽

2018 ◽

Vol 155 (4) ◽

pp. 295-326 ◽

Cited By ~ 2

Author(s):

Karina Charest Castro ◽

Mathieu Leblond ◽

Steeve D. Côté

Keyword(s):

Life History ◽

Body Mass ◽

Life History Traits ◽

The Body ◽

Costs And Benefits ◽

Short Term ◽

Maternal Characteristics ◽

Oreamnos Americanus ◽

Lactating Mothers ◽

Mountain Goats

Abstract To better understand the potential costs and benefits of prolonged parental care in gregarious species, we studied post-weaning associations in a marked population of mountain goats (Oreamnos americanus) monitored for 22 years. We calculated the occurrence and frequency of associations involving 1- and 2-year-old juveniles. We investigated (1) the influence of maternal characteristics and population size on the formation of post-weaning associations, (2) the short-term costs of associations on maternal reproductive success, and (3) the short-term benefits of associations on life-history traits of juveniles. We found that barren mothers associated more frequently with 1-year-olds than summer yeld and lactating mothers. Associations with 2-year-olds tended to increase the probability that a mother would be barren the following year. Post-weaning associations did not influence the body mass of newborn kids nor the body mass and survival of juveniles. We discuss how benefits for associated juveniles may appear later in life.

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Corticosterone, testosterone and life-history strategies of birds

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.0673 ◽

2010 ◽

Vol 277 (1697) ◽

pp. 3203-3212 ◽

Cited By ~ 167

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.

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Artificial selection on male size depletes genetic variance but not covariance of life history traits in the yellow dung fly

10.1101/664326 ◽

2019 ◽

Author(s):

WU Blanckenhorn ◽

V Llaurens ◽

C Reim ◽

Y Teuschl ◽

E Postma

Keyword(s):

Genetic Variation ◽

Life History ◽

Body Size ◽

Artificial Selection ◽

Development Time ◽

Life History Traits ◽

Genetic Variance ◽

Genetic Correlations ◽

Male Size ◽

First Clutch

SUMMARYThe evolutionary potential of organisms depends on the presence of sufficient genetic variation for traits subject to selection, as well as on the genetic covariances among them. While genetic variation ultimately derives from mutation, theory predicts the depletion of genetic (co)variation under consistent directional or stabilizing selection in natural populations. We estimated and compared additive genetic (co)variances for several standard life history traits, including some for which this has never been assessed, before and after 24 generations of artificial selection on male size in the yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) using a series of standard half-sib breeding experiments. As predicted, genetic variances (VA), heritabilities (h2) and evolvabilities (IA) of body size, development time, first clutch size, and female age at first clutch were lower after selection. As independent selection lines were crossed prior to testing, we can rule out that this reduction is due to genetic drift. In contrast to the variances, and against expectation, the additive genetic correlations between the sexes for development time and body size remained strong and positive (rA = 0.8–0.9), while the genetic correlation between these traits within the sexes tended to strengthen (but not significantly so). Our study documents that the effect of selection on genetic variance is predictable, whereas that on genetic correlations is not.

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The metabolic pace of life histories across fishes

10.1101/2020.11.16.385559 ◽

2020 ◽

Author(s):

Serena Wong ◽

Jennifer S. Bigman ◽

Nicholas K. Dulvy

Keyword(s):

Life History ◽

Metabolic Rate ◽

Growth Performance ◽

Body Mass ◽

Life Histories ◽

Life History Traits ◽

Generation Length ◽

Pace Of Life ◽

Trade Offs ◽

Maximum Body

AbstractAll life acquires energy through metabolic processes and that energy is subsequently allocated to life-sustaining functions such as survival, growth, and reproduction. Thus, it has long been assumed that metabolic rate is related to the life history of an organism. Indeed, metabolic rate is commonly believed to set the pace of life by determining where an organism is situated along a fast-slow life history continuum. However, empirical evidence of a relationship between metabolic rate and life histories is lacking, especially for ectothermic organisms. Here, we ask whether three life history traits – maximum body mass, generation length, and growth performance – explain variation in resting metabolic rate (RMR) across fishes. We found that growth performance, which accounts for the trade-off between growth rate and maximum body size, explained variation in RMR, yet maximum body mass and generation length did not. Our results suggest that measures of life history that encompass trade-offs between life history traits, rather than traits in isolation, explain variation in RMR across fishes. Ultimately, understanding the relationship between metabolic rate and life history is crucial to metabolic ecology and has the potential to improve prediction of the ecological risk of data-poor species.

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Direct and correlated responses to bi-directional selection on pre-adult development time in Drosophila montana

Journal of Insect Physiology ◽

10.1016/j.jinsphys.2019.04.004 ◽

2019 ◽

Vol 116 ◽

pp. 77-89 ◽

Cited By ~ 1

Author(s):

Hannele Kauranen ◽

Johanna Kinnunen ◽

David Hopkins ◽

Anneli Hoikkala

Keyword(s):

Adult Development ◽

Development Time ◽

Directional Selection ◽

Correlated Responses ◽

Drosophila Montana

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Impact of Larval Competition on Life-History Traits of the Black Soldier Fly (Diptera: Stratiomyidae)

Annals of the Entomological Society of America ◽

10.1093/aesa/saz014 ◽

2019 ◽

Vol 112 (6) ◽

pp. 505-510 ◽

Cited By ~ 2

Author(s):

Brittny M Jones ◽

Jeffery K Tomberlin

Keyword(s):

Life History ◽

Development Time ◽

Life History Traits ◽

Larval Density ◽

Adult Emergence ◽

Adult Longevity ◽

Larval Competition ◽

Black Soldier Fly ◽

Waste Products ◽

The Impact

Abstract The black soldier fly, Hermetia illucens (L.), is economically important due to its use in waste management and as an alternative protein source for livestock, poultry, and aquaculture. While industry promotes mass production of the black soldier fly, little is known about the impact of larval competition on development time, resulting immature and adult weight, or adult longevity. The goal of this research was to examine the life-history traits of black soldier flies when reared at four densities (500, 1,000, 1,500, and 2,000 larvae/4-liter container) provided 54-g Gainesville diet at 70% moisture (feed rates of 0.027, 0.036, 0.054, and 0.108 g) every other day. Results were as expected with the lowest larval density (500) producing heavier individuals (by 26%) than the greatest larval density (2,000) across all life stages. In addition to weights, larvae reared at the lowest density developed 63% faster than those reared at the greatest density. In regard to pupal development time, those reared at the lowest larval density developed 3% slower than the greatest density. A 21% difference between the two extreme densities was found in survivorship to prepupal stage, with the lowest larval density having the greatest survivorship (92%) compared with the greatest larval density (70%). All densities displayed over 90% adult emergence rates. Such information is vital for optimization of the process of converting waste products to protein at an industrial scale with the black soldier fly.

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Long-Term Seeding Outcomes in Slash Piles and Skid Trails after Conifer Removal

Forests ◽

10.3390/f11080839 ◽

2020 ◽

Vol 11 (8) ◽

pp. 839

Author(s):

Becky K. Kerns ◽

Michelle A. Day ◽

Dana Ikeda

Keyword(s):

Life History ◽

Life History Traits ◽

Fire Hazard ◽

Fire Behavior ◽

Treatment Strategies ◽

Seed Source ◽

Seed Sources ◽

Before And After ◽

Exotic Grass

Conifer removal in interior woodland ecosystems of the western US is a common management treatment used to decrease fire hazard and shift woodlands to more historical states. Woody material is frequently removed by skidding material off site and via slash pile burning. Assessing the long-term outcomes of seeding treatments after such ground disturbing activities is critical for informing future management and treatment strategies. Using two designed experiments from a central Oregon juniper woodland, we resampled slash piles and skid trails 8 years after seeding. Our objectives were to assess the long-term vegetation response to conifer removal, ground disturbance, and seeding source (cultivar and local) in slash piles and skid trails. We found that seeded species persisted in the long term, but abundance patterns depended on the species, seed source, and the type of disturbance. In general, there were more robust patterns of persistence after pile burning compared to skid trails. Seeding also suppressed exotic grass cover in the long term, particularly for the local seed source. However, the invasion levels we report are still problematic and may have impacts on biodiversity, forage and fire behavior. Our short-term results were not predictive of longer-term outcomes, but short- and long-term patterns were somewhat predictable based on species life history traits and ecological succession. The use of a mix of species with different life history traits may contribute to seeding success in terms of exotic grass suppression. Lastly, our results suggest that locally adapted seed sources may perform as well or better compared to cultivars. However, more aggressive weed treatments before and after conifer removal activities and wider seeding application may be needed to effectively treat exotic grass populations.

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