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1.
PLoS One ; 15(8): e0237315, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866153

RESUMO

The decision to allocate time and energy to find multiple sexual partners or raise children is a fundamental reproductive trade-off. The Strategic Pluralism Hypothesis argues that human reproductive strategies are facultatively calibrated towards either investing in mating or parenting (or a mixture), according to the expression of features dependent on the individual's condition. This study seeks to test predictions derived from this hypothesis in a sample of 242 young men (M ± SD = 22.12 ± 3.08) from Chile's 5th Region (33Ö¯ south latitude). Specifically, two predictions were considered that raise questions about the relationship between traits related to physical and psychological attractiveness (fluctuating facial asymmetry and self-perception of attractiveness) and competitive skills (baseline testosterone and self-perception of fighting ability) with short-term reproductive strategies. Our results indicate that psychological features related to the self-perception of physical attractiveness are related to short-term reproductive strategies. However, no evidence was found that fluctuating facial asymmetry, basal levels of testosterone and self-perception of fighting ability were related to short-term reproductive strategies. These results support the existing evidence of the importance of physical attractiveness in calibrating men's reproductive strategies but cast doubts about the role of fluctuating facial asymmetry. They also suggest that traits related to physical attractiveness, in comparison to competitive capabilities, play a more important role in calibrating men's short-term reproductive strategies.


Assuntos
Beleza , Comportamento de Escolha , Reprodução/fisiologia , Autoimagem , Comportamento Sexual/psicologia , Adolescente , Adulto , Chile , Comportamento Competitivo/fisiologia , Humanos , Parceiros Sexuais/psicologia , Inquéritos e Questionários/estatística & dados numéricos , Testosterona/sangue , Testosterona/fisiologia , Adulto Jovem
2.
PLoS One ; 15(8): e0225355, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750055

RESUMO

Across taxa, sex-specific demands vary temporally in accordance with reproductive investments. In solitary carnivores, females must provision and protect young independently while meeting increased energetic demands. Males seek to monopolize access to females by maintaining large territories and defending them from other males. For many species, it is poorly understood how these demands relate to broad-scale animal movements. To investigate predictions surrounding the reproductive strategies of solitary carnivores and effects of local conditions on bobcat (Lynx rufus) spatial ecology, we examined the effects of sex and reproductive season on home range size, movement rate, and resource selection of bobcats in the central Appalachian Mountains. Male seasonal home ranges were approximately 3 times larger than those of females (33.9 ± 2.6 vs. 12.1 ± 2.4 km2, x±SE), and male movement rates were 1.4 times greater than females (212.6 ± 3.6 vs. 155 ± 8.2 m/hr), likely reflecting male efforts to maximize access to females. Both sexes appear to maintain relatively stable seasonal home ranges despite temporally varying reproductive investments, instead adjusting movements within home ranges. Males increased movements during the dispersal period, potentially reflecting increased territoriality prior to breeding. Females increased movements during the kitten-rearing period, when foraging more intensively, and frequently returning to den sites. Both sexes selected home ranges at higher elevations. However, females selected deciduous forest and avoided fields, whereas males selected fields and avoided deciduous forest, perhaps explained by male pressure to access multiple females across several mountain ridges and higher risk tolerance. Seasonal changes in home range selection likely reflect changes in home range shape. Increased female avoidance of fields during kitten rearing may indicate female avoidance of presumably resource rich, yet risky, fields at the time when kittens are most vulnerable. Our results indicate that while reproductive chronology influences the spatial ecology of solitary carnivores, effects may be constrained by territoriality.


Assuntos
Demografia/tendências , Lynx/fisiologia , Reprodução/fisiologia , Animais , Região dos Apalaches , Gatos , Ecossistema , Feminino , Florestas , Comportamento de Retorno ao Território Vital , Masculino , Movimento , Estações do Ano , Caracteres Sexuais , Territorialidade , Virginia
3.
PLoS One ; 15(8): e0236290, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785214

RESUMO

High and variable pre-weaning mortality is a persistent problem in laboratory mouse breeding. Assuming a modest 15% mortality rate across mouse strains, means that approximately 1 million more pups are produced yearly in the EU to compensate for those which die. This paper presents the first large study under practical husbandry conditions to determine the risk factors associated with mouse pre-weaning mortality. We analysed historical records from 219,975 pups from two breeding facilities, collected as part of their management routine and including information on number of pups born and weaned per litter, parents' age and identification, and dates of birth and death of all animals. Pups were counted once in their first week of life and at weaning, and once every one or two weeks, depending on the need for cage cleaning. Dead pups were recorded as soon as these were found during the daily cage screening (without opening the cage). It was hypothesized that litter overlap (i.e. the presence of older siblings in the cage when new pups are born), a recurrent social configuration in trio-housed mice, is associated with increased newborn mortality, along with advanced dam age, large litter size, and a high number and age of older siblings in the cage. The estimated probability of pup death was two to seven percentage points higher in cages with litter overlap compared to those without. Litter overlap was associated with an increase in death of the entire litter of five and six percentage points, which represent an increase of 19% and 103% compared to non-overlapped litters in the two breeding facilities, respectively. Increased number and age of older siblings, advanced dam age, small litter size (less than four pups born) and large litter size (over 11 pups born) were associated with increased probability of pup death.


Assuntos
Animais de Laboratório/fisiologia , Cruzamento/métodos , Ciência dos Animais de Laboratório/métodos , Tamanho da Ninhada de Vivíparos/fisiologia , Camundongos Endogâmicos C57BL/fisiologia , Fatores Etários , Animais , Feminino , Masculino , Idade Materna , Camundongos , Gravidez , Reprodução/fisiologia , Desmame
4.
PLoS One ; 15(8): e0233627, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804928

RESUMO

We studied avian development in 49 to 153 species of temperate and tropical New World passerine birds to determine how growth rates, and incubation and nestling periods, varied in relation to other life-history traits. We collected growth data and generated unbiased mass and tarsus growth rate estimates (mass n = 92 species, tarsus n = 49 species), and measured incubation period (n = 151) and nestling period (n = 153), which we analyzed with respect to region, egg mass, adult mass, clutch size, parental care type, nest type, daily nest predation rate (DMR), and nest height. We investigated covariation of life-history and natural-history attributes with the four development traits after controlling for phylogeny. Species in our lowland tropical sample grew 20% (incubation period), 25% (mass growth rate), and 26% (tarsus growth rate) more slowly than in our temperate sample. Nestling period did not vary with respect to latitude, which suggests that tropical songbirds fledge in a less well-developed state than temperate species. Suboscine species typically exhibited slower embryonic and post-embryonic growth than oscine passerines regardless of their breeding region. This pattern of slow development in tropical species could reflect phylogenetic effects based on unknown physiological attributes. Time-dependent nest mortality was unrelated to nestling mass growth rate, tarsus growth rate, and incubation period, but was significantly associated with nestling period. This suggests that nest predation, the predominant cause of nest loss in songbirds, does not exert strong selection on physiologically constrained traits, such as embryonic and post-embryonic growth, among our samples of temperate and lowland tropical songbird species. Nestling period, which is evolutionarily more labile than growth rate, was significantly shorter in birds exposed to higher rates of nest loss and nesting at lower heights, among other traits. Differences in life-history variation across latitudes provide insight into how unique ecological characteristics of each region influence physiological processes of passerines, and thus, how they can shape the evolution of life histories. While development traits clearly vary with respect to latitude, trait distributions overlap broadly. Life-history and natural history associations differ for each development trait, which suggests that unique selective pressures or constraints influence the evolution of each trait.


Assuntos
Aves Canoras/crescimento & desenvolvimento , Animais , Evolução Biológica , Clima , Tamanho da Ninhada , Análise Discriminante , Ecossistema , Feminino , Traços de História de Vida , Modelos Lineares , Masculino , Michigan , Modelos Biológicos , Comportamento de Nidação/fisiologia , Oregon , Panamá , Filogenia , Comportamento Predatório/fisiologia , Reprodução/fisiologia , Seleção Genética , Aves Canoras/classificação , Aves Canoras/fisiologia , Especificidade da Espécie , Tarso Animal/crescimento & desenvolvimento , Clima Tropical
5.
PLoS One ; 15(8): e0236660, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785239

RESUMO

Squamate reptiles (snakes and lizards) rely on chemical cues from conspecifics to search the environment for potential mates. How such cues are used by invasive species to facilitate reproduction, especially seasonally, is a key question that can inform management practices. The Argentine black and white tegu (Salvator merianae) is an invasive reptile species in south Florida threatening native fauna in biodiverse regions such as Everglades National Park. While some information exists on the reproductive ecology of this species in its native range in South America, the chemical ecology of S. merianae is unclear especially in its invasive range. By testing both male (n = 7) and female (n = 7) tegus in a Y-maze apparatus, we assessed if either sex follows chemical trails left by conspecifics and if behaviors were sex- or season-specific. We conducted three types of trials where conspecifics created odor trails: Male-only (male scent only in base and one arm of Y), Female-only, and Male vs. female. Males did not preferentially follow scent trails from either sex, but they did differentially investigate conspecific scent from both sexes. Seasonally, males showed increased rates of chemosensory sampling (rates of tongue-flicking) during the spring (breeding season; March-May) compared to fall (non-breeding season; September-November). Males also had reduced turning and pausing behavior while trailing in the spring. Female tegus exhibited stronger conspecific trailing abilities than males, following both male and female scent trails, and they explored the maze less before making an arm choice. Females also investigated the scent trails intensely compared to males (more passes in scented arms, more time with scent trails). Our results demonstrate for the first time that females of an invasive reptile species can follow conspecific scent trails. Given the strong female responses to odor, sex-specific targeting of tegus via application of a conspecific chemical cue in traps could enhance removal rates of females during the breeding season.


Assuntos
Lagartos/fisiologia , Casamento , Comportamento Sexual Animal/fisiologia , Serpentes/fisiologia , Animais , Ecologia , Feminino , Florida , Humanos , Espécies Introduzidas , Masculino , Odorantes/análise , Reprodução/fisiologia , América do Sul
7.
PLoS One ; 15(8): e0237720, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32834011

RESUMO

BACKGROUND: Underweight, overweight, and obesity are major public health challenges among reproductive-age women of lower- and middle-income countries (including Tanzania). In those settings, obesogenic factors (attributes that promote excessive body weight gain) are increasing in the context of an existing high burden of undernutrition. The present study investigated factors associated with underweight, overweight, and obesity among reproductive age women in Tanzania. METHODS: This study used 2015-16 Tanzania Demographic and Health Survey data (n = 11735). To account for the hierarchical nature of the data (i.e., reproductive age women nested within clusters), multilevel multinomial logistic regression models were used to investigate the association between individual-level (socioeconomic, demographic and behavioural) and community-level factors with underweight, overweight, and obesity. RESULTS: Reproductive age women who were informally employed (relative risk ratio [RRR] = 0.79; 95% confidence interval [CI]: 0.64, 0.96), those who were currently married (RRR = 0.59; 95% CI: 0.43, 0.82) and those who used contraceptives (RRR = 0.70; 95% CI: 0.54, 0.90) were less likely to be underweight. Reproductive age women who attained secondary or higher education (RRR = 1.48; 95% CI: 1.11, 1.96), those who resided in wealthier households (RRR = 2.31; 95% CI: 1.78, 3.03) and those who watched the television (RRR = 1.26; 95% CI: 1.06, 1.50) were more likely to be overweight. The risk of experiencing obesity was higher among reproductive age women who attained secondary or higher education (RRR = 1.79; 95% CI: 1.23, 2.61), those who were formally employed (RRR = 1.50; 95% CI: 1.14, 1.98), those who resided in wealthier households (RRR = 4.77; 95% CI: 3.03, 7.50), those who used alcohol (RRR = 1.43; 95% CI: 1.12, 1.82) and/or watched the television (RRR = 1.70; 95% CI: 1.35, 2.13). CONCLUSION: Our study suggests that relevant government jurisdictions need to identify, promote, and implement evidence-based interventions that can simultaneously address underweight and overweight/obesity among reproductive age women in Tanzania.


Assuntos
Necessidades e Demandas de Serviços de Saúde/organização & administração , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Saúde Reprodutiva/estatística & dados numéricos , Magreza/epidemiologia , Adolescente , Adulto , Estudos Transversais , Medicina Baseada em Evidências/organização & administração , Medicina Baseada em Evidências/estatística & dados numéricos , Feminino , Necessidades e Demandas de Serviços de Saúde/estatística & dados numéricos , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , Estado Nutricional/fisiologia , Obesidade/fisiopatologia , Obesidade/prevenção & controle , Sobrepeso/fisiopatologia , Sobrepeso/prevenção & controle , Prevalência , Serviços Preventivos de Saúde/organização & administração , Serviços Preventivos de Saúde/estatística & dados numéricos , Reprodução/fisiologia , Fatores de Risco , Fatores Socioeconômicos , Tanzânia/epidemiologia , Magreza/fisiopatologia , Magreza/prevenção & controle , Adulto Jovem
8.
Adv Exp Med Biol ; 1265: 111-131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32761573

RESUMO

Amino acids are not only the building blocks of proteins, an indispensable component of cells, but also play versatile roles in regulating cell metabolism, proliferation, differentiation and growth by themselves or through their derivatives. At the whole body level, the bioavailability and metabolism of amino acids, interacting with other macronutrients, is critical for the physiological processes of reproduction including gametogenesis, fertilization, implantation, placentation, fetal growth and development. In fertilization and early pregnancy, histotroph in oviductal and uterine secretions provides nutrients and microenvironment for conceptus (embryo and extraembryonic membranes) development. These nutrients include select amino acids in histotroph (arginine, leucine and glutamine of particular interest) that stimulate conceptus growth and development, as well as interactions between maternal uterus and the conceptus, thus impacting maintenance of pregnancy, placental growth, development and functions, fetal growth and development, and consequential pregnancy outcomes. Gestational protein undernutrition causes fetal growth restriction and predisposes cardiovascular, metabolic diseases and others in offspring via multiple mechanisms, whereas the supplementation of glycine, leucine and taurine during pregnancy partially rescues growth restriction and beneficially modulates fetal programming. Thus, amino acids are essential for the fertility of humans and all animals.


Assuntos
Aminoácidos/metabolismo , Fenômenos Fisiológicos da Nutrição Materna , Reprodução/fisiologia , Animais , Implantação do Embrião , Feminino , Desenvolvimento Fetal , Humanos , Gravidez , Útero/metabolismo
9.
PLoS One ; 15(8): e0237444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813753

RESUMO

Animal structural body size and condition are often measured to evaluate individual health, identify responses to environmental change and food availability, and relate food availability to effects on reproduction and survival. A variety of condition metrics have been developed but relationships between these metrics and vital rates are rarely validated. Identifying an optimal approach to estimate the body condition of polar bears is needed to improve monitoring of their response to decline in sea ice habitat. Therefore, we examined relationships between several commonly used condition indices (CI), body mass, and size with female reproductive success and cub survival among polar bears (Ursus maritimus) measured in two subpopulations over three decades. To improve measurement and application of morphometrics and CIs, we also examined whether CIs are independent of age and structural size-an important assumption for monitoring temporal trends-and factors affecting measurement precision and accuracy. Maternal CIs and mass measured the fall prior to denning were related to cub production. Similarly, maternal CIs, mass, and length were related to the mass of cubs or yearlings that accompanied her. However, maternal body mass, but not CIs, measured in the spring was related to cub production and only maternal mass and length were related to the probability of cub survival. These results suggest that CIs may not be better indicators of fitness than body mass in part because CIs remove variation associated with body size that is important in affecting fitness. Further, CIs exhibited variable relationships with age for growing bears and were lower for longer bears despite body length being related to cub survival and female reproductive success. These results are consistent with findings from other species indicating that body mass is a useful metric to link environmental conditions and population dynamics.


Assuntos
Tamanho Corporal , Ursidae/fisiologia , Animais , Regiões Árticas , Cruzamento , Ecossistema , Feminino , Masculino , Oceanos e Mares , Reprodução/fisiologia , Estações do Ano , Ursidae/crescimento & desenvolvimento
10.
Rev Chilena Infectol ; 37(1): 64-68, 2020 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-32730402

RESUMO

We remember Lazaro Spallanzani (1729-1799) mainly for his controversy with Needham over spontaneous generation, but he was a man of multiple scientific activities in the fields of biology, mineralogy, physics, mathematics and… volcanology! Called "the biologist of biologists", he developed a series of investigations about reproduction of amphibian, in one of them -Experiences in service to the history of the generation of animals and plants- we have found horrific experiments with frogs, including severe and useless mutilation of males, in order to interrupt its copulation with females, acts he describes as "barbaric", and we estimate inadmissible in the ecclesiastic man he was, even in an epoch in which animals were considered "anima vili" (something without value). A brief review of the use of animals in laboratories shows significant advances in the ethical regulations for this practice, but we believe that these achievements are not enough.


Assuntos
Bem-Estar do Animal , Laboratórios , Bem-Estar do Animal/história , Bem-Estar do Animal/normas , Animais , Animais de Laboratório , Feminino , História do Século XVIII , Laboratórios/ética , Masculino , Reprodução/fisiologia , Ciência/ética , Ciência/história
11.
Fertil Steril ; 114(1): 33-43, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32622411

RESUMO

OBJECTIVE: To identify cell types in the male and female reproductive systems at risk for SARS-CoV-2 infection because of the expression of host genes and proteins used by the virus for cell entry. DESIGN: Descriptive analysis of transcriptomic and proteomic data. SETTING: Academic research department and clinical diagnostic laboratory. PATIENT(S): Not applicable (focus was on previously generated gene and protein expression data). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Identification of cell types coexpressing the key angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) genes and proteins as well as other candidates potentially involved in SARS-CoV-2 cell entry. RESULT(S): On the basis of single-cell RNA sequencing data, coexpression of ACE2 and TMPRSS2 was not detected in testicular cells, including sperm. A subpopulation of oocytes in nonhuman primate ovarian tissue was found to express ACE2 and TMPRSS2, but coexpression was not observed in ovarian somatic cells. RNA expression of TMPRSS2 in 18 samples of human cumulus cells was shown to be low or absent. There was general agreement between publicly available bulk RNA and protein datasets in terms of ACE2 and TMPRSS2 expression patterns in testis, ovary, endometrial, and placental cells. CONCLUSION(S): These analyses suggest that SARS-CoV-2 infection is unlikely to have long-term effects on male and female reproductive function. Although the results cannot be considered definitive, they imply that procedures in which oocytes are collected and fertilized in vitro are associated with very little risk of viral transmission from gametes to embryos and may indeed have the potential to minimize exposure of susceptible reproductive cell types to infection in comparison with natural conception.


Assuntos
Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Fertilidade/fisiologia , Regulação Viral da Expressão Gênica/fisiologia , Pneumonia Viral/metabolismo , Reprodução/fisiologia , Internalização do Vírus , Adolescente , Adulto , Animais , Betacoronavirus/genética , Linhagem Celular , Infecções por Coronavirus/genética , Feminino , Humanos , Macaca fascicularis , Masculino , Ovário/citologia , Ovário/metabolismo , Ovário/virologia , Pandemias , Peptidil Dipeptidase A/biossíntese , Peptidil Dipeptidase A/genética , Pneumonia Viral/genética , Gravidez , Proteômica/métodos , Serina Endopeptidases/biossíntese , Serina Endopeptidases/genética , Testículo/citologia , Testículo/metabolismo , Testículo/virologia , Transcriptoma/fisiologia , Adulto Jovem
12.
PLoS One ; 15(7): e0235464, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32658938

RESUMO

Understanding locomotor activity patterns would reveal key information about an animal's foraging strategy, energy budget and evolutionary adaptation. We studied the locomotor activity patterns of the takin (Budorcas taxicolor) in a temperate mountain region in China using GPS radio-collar technology from 1 July 2014 to 30 June 2015. Our research showed that takin had a bimodal crepuscular locomotor activity pattern, with an especially obvious movement peak at dusk. The takins showed significant seasonal differences in their movement rates, with the lowest movement rate in winter. The animals also showed sexual differences in their movement rates. In spring, the female movement rate was significantly higher than that of males during daytime, while during nighttime the movement rate of males was higher than that of females. The male movement rate was significantly higher than that of females in summer. The movement rate of the takins were correlated to microenvironment temperature and normalized difference vegetation index (NDVI) in each season. These findings suggest that takin could adjust locomotor activity levels adapt to reproductive requirements, temperature variation and forage variability.


Assuntos
Locomoção/fisiologia , Reprodução/fisiologia , Ruminantes/fisiologia , Animais , China , Feminino , Sistemas de Informação Geográfica , Masculino , Filogenia , Estações do Ano
14.
PLoS One ; 15(6): e0235478, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32603379

RESUMO

OBJECTIVE: Most women live to experience menopause and will spend 4-8 years transitioning from fertile age to full menstrual stop. Biologically, reproductive ageing is a continuous process, but by convention, it is defined categorically as pre-, peri- and postmenopause; categories that are sometimes supported by measurements of sex hormones in blood samples. We aimed to develop and validate a new tool, a reproductive ageing score (RAS), that could give a simple and yet precise description of the status of reproductive ageing, without hormone measurements, to be used by health professionals and researchers. METHODS: Questionnaire data on age, menstrual regularity and menstrual frequency was provided by the large multicentre population-based RHINE cohort. A continuous reproductive ageing score was developed from these variables, using techniques of fuzzy mathematics, to generate a decimal number ranging from 0.00 (nonmenopausal) to 1.00 (postmenopausal). The RAS was then validated with sex hormone measurements (follicle stimulating hormone and 17ß-estradiol) and interview-data provided by the large population-based ECRHS cohort, using receiver-operating characteristics (ROC). RESULTS: The RAS, developed from questionnaire data of the RHINE cohort, defined with high precision and accuracy the menopausal status as confirmed by interview and hormone data in the ECRHS cohort. The area under the ROC curve was 0.91 (95% Confidence interval (CI): 0.90-0.93) to distinguish nonmenopausal women from peri- and postmenopausal women, and 0.85 (95% CI: 0.83-0.88) to distinguish postmenopausal women from nonmenopausal and perimenopausal women. CONCLUSIONS: The RAS provides a useful and valid tool for describing the status of reproductive ageing accurately, on a continuous scale from 0.00 to 1.00, based on simple questions and without requiring blood sampling. The score allows for a more precise differentiation than the conventional categorisation in pre-, peri- and postmenopause. This is useful for epidemiological research and clinical trials.


Assuntos
Envelhecimento/fisiologia , Menopausa/fisiologia , Adulto , Idoso , Estudos de Coortes , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Perimenopausa , Pós-Menopausa , Reprodução/fisiologia , Inquéritos e Questionários/estatística & dados numéricos
15.
PLoS One ; 15(6): e0235388, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32604405

RESUMO

The plasticity of different kelp populations to heat stress has seldom been investigated excluding environmental effects due to thermal histories, by raising a generation under common garden conditions. Comparisons of populations in the absence of environmental effects allow unbiased quantification of the meta-population adaptive potential and resolution of population-specific differentiation. Following this approach, we tested the hypothesis that genetically distinct arctic and temperate kelp exhibit different thermal phenotypes, by comparing the capacity of their microscopic life stages to recover from elevated temperatures. Gametophytes of Laminaria digitata (Arctic and North Sea) grown at 15°C for 3 years were subjected to common garden conditions with static or dynamic (i.e., gradual) thermal treatments ranging between 15 and 25°C and also to darkness. Gametophyte growth and survival during thermal stress conditions, and subsequent sporophyte recruitment at two recovery temperatures (5 and 15°C), were investigated. Population-specific responses were apparent; North Sea gametophytes exhibited higher growth rates and greater sporophyte recruitment than those from the Arctic when recovering from high temperatures, revealing differential thermal adaptation. All gametophytes performed poorly after recovery from a static 8-day exposure at 22.5°C compared to the response under a dynamic thermal treatment with a peak temperature of 25°C, demonstrating the importance of gradual warming and/or acclimation time in modifying thermal limits. Recovery temperature markedly affected the capacity of gametophytes to reproduce following high temperatures, regardless of the population. Recovery at 5°C resulted in higher sporophyte production following a 15°C and 20°C static exposure, whereas recovery at 15°C was better for gametophyte exposures to static 22.5°C or dynamic heat stress to 25°C. The subtle performance differences between populations originating from sites with contrasting local in situ temperatures support our hypothesis that their thermal plasticity has diverged over evolutionary time scales.


Assuntos
Aclimatação/fisiologia , Resposta ao Choque Térmico/fisiologia , Laminaria/fisiologia , Regiões Árticas , Células Germinativas Vegetais/crescimento & desenvolvimento , Células Germinativas Vegetais/fisiologia , Aquecimento Global , Temperatura Alta , Laminaria/crescimento & desenvolvimento , Mar do Norte , Fenótipo , Reprodução/fisiologia , Temperatura
16.
PLoS One ; 15(7): e0236489, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726365

RESUMO

Ground-nesting birds face many challenges to reproduce successfully, with nest predation being the main cause of reproductive failure. Visual predators such as corvids and egg-eating raptors, are among the most common causes of nest failure; thus, parental strategies that reduce the risk of visual nest predation should be favored by selection. To date, most research has focused on egg crypsis without considering adult crypsis, although in natural circumstances the eggs are covered by an incubating parent most of the time. Here we use a ground-nesting shorebird, the Kentish plover (Charadrius alexandrinus) as model species to experimentally test whether decoy parents influence nest predation. Using artificial nests with a male decoy, a female decoy or no decoy, we found that the presence of a decoy increased nest predation (N = 107 nests, p < 0.001). However, no difference was found in predation rates between nests with a male versus female decoy (p > 0.05). Additionally, we found that nests in densely vegetated habitats experienced higher survival compared to nests placed in sparsely vegetated habitats. Nest camera images, predator tracks and marks left on eggs identified the brown-necked raven (Corvus ruficollis) as the main visual nest predator. Our study suggests that the presence of incubating parents may enhance nest detectability to visual predators. However, parents may reduce the predation risk by placing a nest in sites where they are covered by vegetation. Our findings highlight the importance of nest site selection not only regarding egg crypsis but also considering incubating adult camouflage.


Assuntos
Aves/fisiologia , Comportamento de Nidação/fisiologia , Reprodução/fisiologia , Animais , Ecossistema , Feminino , Óvulo/fisiologia , Densidade Demográfica , Comportamento Predatório/fisiologia , Cimentos de Resina/química
17.
Proc Natl Acad Sci U S A ; 117(31): 18557-18565, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690693

RESUMO

Breeding timed to match optimal resource abundance is vital for the successful reproduction of species, and breeding is therefore sensitive to environmental cues. As the timing of breeding shifts with a changing climate, this may not only affect the onset of breeding but also its termination, and thus the length of the breeding period. We use an extensive dataset of over 820K nesting records of 73 bird species across the boreal region in Finland to probe for changes in the beginning, end, and duration of the breeding period over four decades (1975 to 2017). We uncover a general advance of breeding with a strong phylogenetic signal but no systematic variation over space. Additionally, 31% of species contracted their breeding period in at least one bioclimatic zone, as the end of the breeding period advanced more than the beginning. We did not detect a statistical difference in phenological responses of species with combinations of different migratory strategy or number of broods. Nonetheless, we find systematic differences in species responses, as the contraction in the breeding period was found almost exclusively in resident and short-distance migrating species, which generally breed early in the season. Overall, changes in the timing and duration of reproduction may potentially lead to more broods co-occurring in the early breeding season-a critical time for species' reproductive success. Our findings highlight the importance of quantifying phenological change across species and over the entire season to reveal shifts in the community-level distribution of bird reproduction.


Assuntos
Migração Animal/fisiologia , Aves/fisiologia , Reprodução/fisiologia , Animais , Aves/classificação , Mudança Climática , Finlândia , Filogenia , Estações do Ano
18.
BMC Evol Biol ; 20(1): 90, 2020 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703164

RESUMO

BACKGROUND: Mate choice is a taxonomically wide-spread phenomenon, mostly exerted by females although male mate choice occurs as well. While costs and benefits of choosiness have been well studied, the underlying mechanisms are largely unclear. Different models exist, namely best-of-n or threshold rules, based on sequential or simultaneous sampling, which differ in the required cognitive demands. We applied an experimental approach to shed light on the underlying mechanisms of male mate choice in the sexually cannibalistic spider Argiope bruennichi. Males are limited to two copulations and preferentially monopolise large females, while they may leave smaller females after a single copulation and resume mate search. Here, we utilised significant size-differences between females from Northern and Southern populations and presented males with three different-sized females that were matched for origin: all three females originated either from the same Northern European population as the males or from Southern populations where the smallest female was about the same size as the largest Northern female. This allowed testing the hypothesis that males base their mating tactic on a fixed local size threshold. We predicted Northern males to be choosy among Northern females, but to accept all Southern females since they would all be above that threshold. RESULTS: Males copulated with the first female they encountered, which was independent of her body size. Regardless of the females' origins, males chose a monogynous tactic with the largest female in the trio, while they left the smallest female after one copulation. The same pattern applied to Southern females even though the smallest females in the trio were of a similar size as monopolised Northern females. Since males have poor eyesight and did not actively sample all females, they likely have gained information about relative size differences between females based on volatile chemical cues only. CONCLUSIONS: Our findings suggest that male A. bruennichi can assess relative differences in mate quality and adjust their mating tactic to the prevailing conditions (Northern vs. Southern). We reject the presence of a locally-adapted fixed threshold and argue that our results are best explained by an adjustable threshold that was raised under Southern conditions.


Assuntos
Canibalismo , Aranhas/fisiologia , Animais , Tamanho Corporal , Copulação/fisiologia , Feminino , Masculino , Modelos Biológicos , Reprodução/fisiologia
19.
Proc Biol Sci ; 287(1931): 20200806, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32673556

RESUMO

The amount of artificial light at night is growing worldwide, impacting the behaviour of nocturnal organisms. Yet, we know little about the consequences of these behavioural responses for individual fitness and population viability. We investigated if females of the common glow-worm Lampyris noctiluca-which glow in the night to attract males-mitigate negative effects of artificial light on mate attraction by adjusting the timing and location of glowing to spatial variation in light conditions. We found females do not move away from light when exposed to a gradient of artificial light, but delay or even refrain from glowing. Further, we demonstrate that this response is maladaptive, as our field study showed that staying still when exposed to artificial light from a simulated streetlight decreases mate attraction success, while moving only a short distance from the light source can markedly improve mate attraction. These results indicate that glow-worms are unable to respond to spatial variation in artificial light, which may be a factor in their global decline. Consequently, our results support the hypothesis that animals often lack adaptive behavioural responses to anthropogenic environmental changes and underlines the importance of considering behavioural responses when investigating the effects of human activities on wildlife.


Assuntos
Besouros/fisiologia , Animais , Comportamento Animal/fisiologia , Poluição Ambiental , Feminino , Luz , Masculino , Reprodução/fisiologia
20.
Proc Biol Sci ; 287(1931): 20200928, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32693718

RESUMO

Within-individual and among-individual variation in expression of key environmentally sensitive traits, and associated variation in fitness components occurring within and between years, determine the extents of phenotypic plasticity and selection and shape population responses to changing environments. Reversible seasonal migration is one key trait that directly mediates spatial escape from seasonally deteriorating environments, causing spatio-seasonal population dynamics. Yet, within-individual and among-individual variation in seasonal migration versus residence, and dynamic associations with subsequent reproductive success, have not been fully quantified. We used novel capture-mark-recapture mixture models to assign individual European shags (Phalacrocorax aristotelis) to 'resident', 'early migrant', or 'late migrant' strategies in two consecutive years, using year-round local resightings. We demonstrate substantial among-individual variation in strategy within years, and directional within-individual change between years. Furthermore, subsequent reproductive success varied substantially among strategies, and relationships differed between years; residents and late migrants had highest success in the 2 years, respectively, matching the years in which these strategies were most frequently expressed. These results imply that migratory strategies can experience fluctuating reproductive selection, and that flexible expression of migration can be partially aligned with reproductive outcomes. Plastic seasonal migration could then potentially contribute to adaptive population responses to currently changing forms of environmental seasonality.


Assuntos
Migração Animal/fisiologia , Aves/fisiologia , Animais , Feminino , Masculino , Fenótipo , Dinâmica Populacional , Reprodução/fisiologia , Estações do Ano
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