Female Size Research Articles

O-037 An update on the genetics of dizygotic twinning

Abstract Study question Which genes are involved in female fertility defined as giving birth to naturally conceived dizygotic (DZ) twins? Summary answer In 2016 we identified FSHB and SMAD3 as first loci for having DZ twins. We now report four additional loci: GNRH1, FSHR, ZFPM1 and IPO8. What is known already The propensity to give birth to DZ twins differs around the globe, is positively associated with body size and smoking, and runs in families. Heritability estimates tend to be low. Study design, size, duration We conducted a genome-wide association meta-analysis (GWAMA) of mothers of naturally conceived dizygotic (DZ) twins (8,265 cases, 264,567 controls) and of independent DZ twin offspring (26,252 cases, 417,433 controls). Participants were carefully screened to exclude twins born after use of Medically Assisted Reproduction (MAR) technologies. Participants/materials, setting, methods Over 700.000 participants from Australia, New Zealand, Europe and USA were included. Genetic association analyses by cohort for being a mother of DZ twins and being a DZ twin were combined by fixed-effects inverse variance methods as implemented in METAL software meta-analysis. To predict the most likely effector gene in a locus, we applied the new FLAMES framework which integrates machine learning with biological data linking SNPs to genes, and GWAS-wide convergence of gene interactions. Main results and the role of chance By enlarging sample size from previous efforts, both by including new cohorts and by combining through meta-analyses with independent DZ offspring, we identified 4 genome-wide significant loci, in addition to FSHB (follicle stimulating hormone subunit beta ) and SMAD3 (SMAD family member 3). Two novel loci GNRH1 (gonadotropin releasing hormone 1) and FSHR (follicle stimulating hormone receptor) have well-established roles in female reproduction. The 2 further novel genes were implicated by gene level enrichment analyses. Both ZFPM1 (Zinc Finger Protein, FOG Family Member 1) and IPO8 (Importin 8) have not previously been implicated. Significant genetic correlations were found with multiple aspects of female reproduction and body size as well as with a recent GWAMA of female infertility. The 26 top SNPs from our GWAMA in European-origin participants predicted the crude twinning rates in 47 non-European populations (r = 0.23 between risk score and population prevalence, p=.058) indicating that GWAS are needed in African and Asian populations to explore the causes of their respectively high and low DZ twinning rates. A Phenome-wide association study (PheWAS) based on the GWAMA, linked SNPs predisposing to DZT with reduced risk of both ovarian dysfunction and polycystic ovaries. Limitations, reasons for caution So far, our studies only included European ancestry cohorts. Inclusion of data from Africa (the highest world-wide DZ twining rates are observed in Western Africa) and Asia (lowest DZ twinning rate) will further illuminate the etiology of twinning and female fertility. Wider implications of the findings About one in 40 babies born in the world is a twin and there is still much unknown why they run in families. We hope our results will inform investigations of female fertility and infertility. Trial registration number not applicable

P-092 PGT-A Evaluates Advanced Sperm Selection in Embryos from High Teratozoospermia Males; a prospective randomized controlled trial

Abstract Study question Can sperm selection techniques improve the reproductive outcomes of ICSI patients, particularly in males with high teratozoospermia index (TZI) and sperm DNA fragmentation (SDF)? Summary answer Sperm selection techniques significantly increase fertilization and blastocyst development rates in males with high TZI and SDF, achieving a euploidy rate comparable to normal cases. What is known already Abnormal sperm morphology negative effects begin at the fertilization and reach the blastocyst quality and euploidy status. Men with abnormal teratozoospermic index (TZI) exhibit high levels of chromosomal abnormalities and sperm DNA fragmentation (SDF). SDF adversely affects pre and post-implantation embryo development events. Blastocyst aneuploidy isn’t solely due to the oocyte; but also, sperm contribution should be taken into consideration. Previous studies reported that advanced sperm selection techniques (PICSI and MACS) can efficiently enhance reproductive outcomes in abnormal SDF ICSI cases. The efficiency of these techniques in improving ICSI outcomes of patients with high TZI plus SDF remains unexplored. Study design, size, duration A prospective randomized controlled trial included a total of 264 couples, divided into three groups: (1) Control-1 group: males having normal TZI and no sperm selection techniques were used (n = 111), (2) Control-2 group (NO-SS): males having high TZI and no sperm selection techniques were used (n = 63), and (3) Sperm selection (SS) group: males having high TZI and SDF, and sperm selection techniques were used (n = 90). The study started from January till October 2023. Participants/materials, setting, methods Eligibility: females had ≥5MII oocytes, males had abnormal (>1.8) TZI, and all blastocysts (≥4BB) had trophoectoderm biopsy. Cases were randomized on the ICSI day to (control-2) and (SS) groups, along with (control-1) with normal TZI for comparison. Females were categorized into 2 subgroups (<35, and ≥35 years). SS techniques included physiological ICSI and magnetic-activated cell sorting. PGT-A was done using Illumina platform (Miseq). Statistical analysis (SPSS) of pre-implantation embryo development and PGT-A results was done. Main results and the role of chance We found no significant differences between the female, male ages and number of mature oocytes between the studied groups. Limitations, reasons for caution The results included all pre-implantation embryo parameters but, subsequent post-implantation events like implantation, pregnancy, and miscarriage rates will add more data about the competency of the resulting embryos. A Small sample size of females aged from 36 to 40 years old. Wider implications of the findings Sperm selection techniques appear to be efficient in improving fertilization, blastocyst development rates, and euploidy rates in males with high TZI and sperm DNA fragmentation, suggesting potential benefits for couples undergoing infertility treatment. Trial registration number NCT06231589

Health-Promoting Benefits of Exercise Awareness and Exercise Behavior in Older Adults: An Exercise Program Intervention

The purpose of this study was to use the aerobic exercise program as an intervention to understand exercise awareness and exercise behavior in older adults and to predict health promotion. This study recruited 120 healthy older adults (60 males and 60 females) over 65 years old (average male age 72.15 ± 3.53 years, female average age 71.64 ± 3.97 years), males and females were randomly assigned to the experimental group, and the control group (30 males, 30 females). The experimental group underwent an “aerobic fitness exercise program” for 8 week, while the control group underwent 8 weeks of daily life. All participants were first surveyed on background variables. At the beginning and end of the experiment, the experimental group and control group of males and females had to undergo the senior fitness test (SFT), the Elderly Exercise Awareness and Exercise Behavior Scale (EAEBI) and the Elderly Health Promotion Inventory (HPI) survey. The results of the study showed that male Cohen’s d = .326, and female Cohen’s d = .371, both showed small effects; related power analysis male effect size (es) = 0.2, female effect size (es) = 0.1, showed that the participants were homogeneous, the mean ages of males and females of the Q-Q plot showed normality. The SFT analysis of the experimental group and the control group found that Int-2, Int-1, Con-1, and Con-2 were significantly different between males and females. The EAEBI scale analysis found that the male experimental group had the largest difference in awareness effect ( F = 9.47, p < .05), and the female experimental group had the largest difference in exercise cognition ( F = 11.35, p < .05). HPI scale analysis found that the male experimental group had the largest difference in physical activity ( F = 14.83, p < .05), and the female experimental group had the largest difference in social support ( F = 13.19, p < .05). Finally, the intervention measures of aerobic fitness exercise program could positively affect the exercise perceived and exercise behavior of the older adults, and had positive effects on health promotion. This study has practical significance for an aging society. Promoting health through regular exercise can also reduce medical resources, which is the subject of effective preventive medicine.

Population dynamics of Penilia avirostris and Pseudevadne tergestina (Diplostraca) in the Veracruz Reef System National Park, southwest Gulf of Mexico

The present study aimed to evaluate the ecology considering distribution, abundance, population structure, and fecundity of the marine diplostraceans Penilia avirostris and Pseudevadne tergestina in the Veracruz Reef System National Park, southwest Gulf of Mexico. Surface samples were collected with a 300 μm mesh plankton net at 26 sampling sites in June, August, October (2011), May (2012) and June (2013). Temperature, salinity, and dissolved oxygen were measured in situ. The temperature range was 26.53 ± 0.41 and 29.29 ± 0.27°C, salinity between 33.43 ± 0.49 and 35.91 ± 0.09, and dissolved oxygen between 2.92 ± 0.08 and 6.56 ± 0.08 mg L-1. P. avirostris and P. tergestina presented the highest density, with 2200 ind 100 m-3 in June and 5980 ind 100 m-3 in October, respectively. Four stages were determined in P. avirostris. In P. tergestina, there were five instars, with males in August and October. The size of parthenogenic females of P. avirostris was 773.4 ± 20.08 μm. In P. tergestina, it was 637.6 ± 49.28 μm. The number of embryos in P. avirostris was 2 to 7, and in P. tergestina, 2 to 8 embryos. The correlations between body length and the number of embryos in both species were statistically significant under the potential model (r > 0.68 for both species, P < 0.001). The transects with the highest abundance were the northern and the southern zones because they are far from the influence of the Jamapa River. The density of these crustaceans is related to optimal temperature, salinity, and dissolved oxygen values. The low proportions obtained from gamogenic individuals of P. avirostris and P. tergestina suggest that in tropical and subtropical regions, gamogenesis is not crucial for the life cycle of these organisms.

Revisão Sistemática de Estudos sobre Bullying no Contexto da Educação Física e Atividade Física

Introduction: Aggressive behaviors such as bullying or School Bullying (SB) in the population are not an isolated event and seriously affect the socio-emotional health of those who suffer it. Objective: The aim of this study was to carry out a systematic review of existing publications on Physical Education (PE) and Physical Activity (PA). Materials and Methods: A research was designed based on PRISMA methodology. The search for information was developed in four databases WOS, PUBMED, SCIELO and ELSEIVER between the years 2015 to 2020. Results: A total of 53 articles were found, after being analyzed by inclusion and exclusion criteria, 18 studies were considered for analysis. Spain, Brazil and Colombia concentrate a greater number of publications with great variability of sample size for both females and males mainly during adolescence. The most used concepts were Bullying; Victimization, School Violence, Cyberbullying, Cyberbullying, Self-esteem within the context of PE and PA. Conclusion: The need to make the problem visible in PE and PA is highlighted, due to its impact on physical and emotional health and motor learning.

Experimental evolution under predation reduces body size in dung flies but courtship displays persist in males (Diptera: Sepsidae)

Exaggerated sexual traits, such as ornaments and courtship displays, are crucial for mate acquisition in many species and are often subject to directional runaway selection. However, in the face of high predation risk, natural selection can result in a reduction of conspicuous precopulatory displays to avoid detection by potential predators. Sexual selection may then favour increased investment in inconspicuous postcopulatory traits. Here, we investigated the transgenerational effects of predation on precopulatory male courtship and postcopulatory sexual traits (testes size, sperm length) in a dung fly, Sepsis punctum (Sepsidae). Behavioural assays prior to selection document a marked decrease in male courtship displays in the presence of a predator, the Asian Ant Mantis (Odontomantis planiceps). However, after ten generations of experimental evolution, flies exhibited a marked increase in courtship, both in the absence and presence of a predator. Additionally, under sustained predation pressure, male and female body size decreased but male postcopulatory traits were not significantly affected. These results suggest that precopulatory courtship can be under strong sexual selection even in the face of predation pressure. Larger flies were more susceptible to predation, and there could be canalisation of postcopulatory traits that are crucial for fertilisation.

Effects of mealybug and female body sizes on host examination and offspring developmental performances in the gregarious hyperparasitoid Cheiloneurus nankingensis

Effects of mealybug and female body sizes on host examination and offspring developmental performances in the gregarious hyperparasitoid Cheiloneurus nankingensis

Resource allocation strategies and mechanical constraints drive the diversification of stick and leaf insect eggs

The diversity of insect eggs is astounding but still largely unexplained. Here, we apply phylogenetic analyses to 208 species of stick and leaf insects, coupled with physiological measurements of metabolic rate and water loss on five species, to evaluate classes of factors that may drive egg morphological diversification: life history constraints, material costs, mechanical constraints, and ecological circumstances. We show support for all three classes, but egg size is primarily influenced by female body size and strongly trades off with egg number. Females that lay relatively fewer but larger eggs, which develop more slowly because of disproportionately low metabolic rates, also tend to bury or glue them in specific locations instead of simply dropping them from the foliage (ancestral state). This form of parental care then directly favors relatively elongated eggs, which may facilitate their placement and allow easier passage through the oviducts in slender species. In addition, flightless females display a higher reproductive output and consequently lay relatively more and larger eggs compared with flight-capable females. Surprisingly, local climatic conditions had only weak effects on egg traits. Overall, our results suggest that morphological diversification of stick insect eggs is driven by a complex web of causal relationships among traits, with dominant effects of resource allocation and oviposition strategies, and of mechanical constraints.

Sex- and caste-specific developmental responses to juvenile hormone in an ant with maternal caste determination.

Juvenile hormone is considered to be a master regulator of polyphenism in social insects. In the ant Cardiocondyla obscurior, whether a female egg develops into a queen or a worker is determined maternally and caste-specific differentiation occurs in embryos, so that queens and workers can be distinguished in a non-invasive manner from late embryogenesis onwards. This ant also exhibits two male morphs - winged and wingless males. Here, we used topical treatment with juvenile hormone III and its synthetic analogue methoprene, a method that influences caste determination and differentiation in some ant species, to investigate whether hormone manipulation affects the development and growth of male, queen- and worker-destined embryos and larvae. We found no effect of hormone treatment on female caste ratios or body sizes in any of the treated stages, even though individuals reacted to heightened hormone availability with increased expression of krüppel-homolog 1, a conserved JH first-response gene. In contrast, hormone treatment resulted in the emergence of significantly larger males, although male morph fate was not affected. These results show that in C. obscurior, maternal caste determination leads to irreversible and highly canalized caste-specific development and growth.

Heart Size Difference Drives Sex-Specific Response to Cardiac Resynchronization Therapy: A Post Hoc Analysis of the MORE-MPP CRT Trial.

Studies have reported that female sex predicts superior cardiac resynchronization therapy (CRT) response. One theory is that this association is related to smaller female heart size, thus increased relative dyssynchrony at a given QRS duration (QRSd). Our objective was to investigate the mechanisms of sex-specific CRT response relating to heart size, relative dyssynchrony, cardiomyopathy type, QRS morphology, and other patient characteristics. This is a post hoc analysis of the MORE-CRT MPP (More Response on Cardiac Resynchronization Therapy with Multipoint Pacing)trial (n=3739, 28% women), with a subgroup analysis of patients with nonischemic cardiomyopathy and left bundle-branch block (n=1308, 41% women) to control for confounding characteristics. A multivariable analysis examined predictors of response to 6 months of conventional CRT, including sex and relative dyssynchrony, measured by QRSd/left ventricular end-diastolic volume (LVEDV). Women had a higher CRT response rate than men (70.1% versus 56.8%, P<0.0001). In subgroup analysis, regression analysis of the nonischemic cardiomyopathy left bundle-branch block subgroup identified QRSd/LVEDV, but not sex, as a modifier of CRT response (P<0.0039). QRSd/LVEDV was significantly higher in women (0.919) versus men (0.708, P<0.001). CRT response was 78% for female patients with QRSd/LVEDV greater than the median value, compared with 68% with QRSd/LVEDV less than the median value (P=0.012). The association between CRT response and QRSd/LVEDV was strongest at QRSd <150 ms. In the nonischemic cardiomyopathy left bundle-branch block population, increased relative dyssynchrony in women, who have smaller heart sizes than their male counterparts, is a driver of sex-specific CRT response, particularly at QRSd <150 ms. Women may benefit from CRT at a QRSd <130 ms, opening the debate on whether sex-specific QRSd cutoffs or QRS/LVEDV measurement should be incorporated into clinical guidelines.

Age structure and body size of two Tibetan toad (Bufo tibetanus) populations from different elevations in China.

Understanding how age and body size vary across elevations can provide insights into the evolution of life-history traits in animals. In the present study, we compared the demographic (using skeletochronology) and morphological traits of the Tibetan toad (Bufo tibetanus) between two populations from different elevational habitats (2650 vs. 3930 m). We found that (1) the mean age and body size of females were significantly greater than those of males in both populations; (2) both sexes of toads from the higher elevation tended to be significantly older in age and larger in body size; (3) there was a significant positive relationship between age and body size within each sex of the toad at both elevations; and (4) growth rates varied between the two populations, with the higher rate observed in the lower-elevation population. Our results suggested that factors other than age, such as elevation-associated temperature, influence the observed differences in body size between the two populations. Future research at a broader range of elevations should focus on these factors and evaluate their influence on animal growth patterns.

Various Comparative Studies of Constantly Applied Methods in Assisting the Demography Research of China

Demography research is of great importance due to it can affect various aspects of a country. We mainly focus on using various comparative studies to examine and predict the population quantity, female size, and urban population size of China. We initially compared the effectiveness of several interpolation algorithms to add more samples and then we constructed two more comparative studies of the Malthus model, Logistic model, GM (1, 1) model, BP neural network, and Leslie model to assist the demography research of China. Especially, three novel metaheuristic algorithms were applied to the Logistic model. Compared results verified that metaheuristics can assist the Logistic model to obtain far more accurate parameters and also revealed that using the Logistic model combined with a novel metaheuristic to predict the population quantity and urban population size and the BP neural network to estimate the female size can acquire the most ideal results.

Life history changes associated with over 400 generations of artificial selection on body size in Drosophila.

Body size is a trait that shapes many aspects of a species' development and evolution. Larger body size is often beneficial in animals, but it can also be associated with life history costs in natural systems. Similarly, miniaturization, the evolution of extremely small adult body size, is found in every major animal group, yet carries its own life history trade-offs. Given that these effects can depend on an animal's environment and life stage and have mainly been studied in species that are already specialized for their size, the life history changes associated with evolutionary shifts in body size warrant additional investigation. Here, we used Drosophila melanogaster populations that had undergone over 400 generations of artificial selection on body size to investigate the changes in life history traits associated with the evolution of extremely large and extremely small body sizes. Populations selected for small body size experienced strong trade-offs in multiple life history traits, including reduced female fecundity and lower juvenile viability. Although we found positively correlated changes in egg size associated with selection for both large and small body size, after adjusting for female body size, females from populations selected for large size had the lowest relative investment per egg and females from populations selected for small size had the highest relative investment per egg. Taken together, our results suggest that egg size may be a key constraint on the evolution of body size in D. melanogaster, providing insight into the broader phenomenon of body size evolution in insects.

Forest harvest causes rapid changes of maternal investment strategies in ground beetles.

Species recovery following anthropogenic disturbances will depend on adaptations in survivorship and fecundity. Life-history theory predicts increased environmental stress will result in (1) shifts in resource allocation from fecundity to body growth/maintenance and (2) increased provisioning among offspring at the cost of reproductive output. For remnant populations that persist after forest harvesting, selection mediated through anthropogenic disturbances may affect resilience to additional stressors such as climate change. We tested how rapid changes in environmental conditions affected maternal investment strategies in two ground beetle species, Pterostichus pensylvanicus and Pterostichus coracinus, by comparing fecundity and survivorship in populations from recently clear-cut and uncut habitats. Using parents drawn from clear-cut or uncut stands, we reared progeny in both common garden and reciprocal transplant experiments. In P. pensylvanicus, we found that neither lineage nor rearing habitat affected the number of eggs laid per female or survivorship of offspring. However, eggs laid by females from clear-cuts were more likely to hatch and offspring reached maturity more quickly, suggesting increased provisioning per offspring. In P. coracinus, females from clear-cuts laid more eggs, and their eggs hatched more rapidly and had greater hatching success, suggesting increased investment in overall reproductive output and increased offspring provisioning. In the reciprocal transplant, we observed significant habitat by lineage interactions on survival in P. coracinus, with survivorship increasing when progeny were reared in novel habitats. In both species, increased maternal investment among offspring was not associated with a reduction in overall reproductive output, as anticipated. However, maternal investment among offspring declined with increasing female size, implying trade-offs between increased metabolic demand and fecundity. Taken together, our work suggests that females from more stressful, clear-cut habitats increased investment in fecundity, compared to females from uncut habitats, and may compensate for larval mortality. These changes were driven by smaller individuals, suggesting that increased environmental stress can influence the relationship between female size and maternal investment strategy. Additionally, reciprocal increases in offspring survivorship in habitats other than the parents suggest that adjacent areas between unharvested and clear-cut habitat may be useful in maintaining biodiversity under future climate stressors.

Tracheal hyperallometry and spatial constraints in a large beetle

Insects exchange respiratory gases with their environment through their gas-filled tracheal system, a branched tracheal tree extending from segmental openings and terminating at fine tissue penetrating tracheoles. It was shown that the tracheal volume increases hyperallometrically with insect body size (Mb), both interspecifically and across developmental stages. In this study, we used the sixfold Mb variation in adult Batocera rufomaculata(Cerambicidae; Coleoptera) examining the allometry of adult tracheal volume (Vtr). We further explored the effect of sex and sexual maturity on tracheal gas conductance, testing the hypotheses that (i) larger body size and (ii) egg volume in gravid females would result in lower safety margins for tracheal oxygen transport due to structural restriction. We report a hyperallometric tracheal growth in both sexes of adult B. rufomaculata(mean mass exponent of 1.42 ± 0.09), similar in magnitude to previously reported values. Tracheal gas conductance was independent of Mb and reproductive state, but was significantly higher in females compared with males. We suggest that females may have pre-adapted a higher tracheal conductance required for the higher flight power output while gravid. Lack of compliant air sacs and rigid trachea may explain how gravid females retain their Vtr. However, we show that Vtr outgrows thoracic dimensions with increased B. rufomaculatasize. Hyperallometric growth of the giant cerambycid thoracic trachea could explain the previously reported hypometric scaling of flight muscles in B. rufomaculata, and the compromised long-distance flight performance of larger compared with smaller conspecifics.

Examining Sex Differences in Relationships Between Subjective and Objective Measures of Upper Extremity Motor Impairment in a Sample of Stroke Survivors.

Rehabilitation professionals use subjective and objective outcome measures to assess stroke-related impact and impairment. Understanding if subjective and objective findings correlate among stroke survivors, especially if these associations differ between females and males, can inform care decisions. A retrospective cross-sectional design was used, with data selected from subacute to chronic stroke survivors on age, time since stroke, the hand domain from the Stroke Impact Scale version 3.0 (SIS-H), and the Fugl-Meyer Upper Extremity (FMUE) Assessment. Group differences were assessed for all outcomes based on sex and time poststroke. Separate correlations for females and males were performed between the subjective (SIS-H) and objective measures (FMUE) of upper limb function and impairment. Data from 148 participants (44 females) were included in this study. SIS-H was significantly correlated with FMUE in both females and males ( P s ≤0.001). No significant differences were found between the groups' mean SIS-H or FMUE scores based on sex or time poststroke. Subjective and objective measures of physical functioning were correlated in both females and males. Although we found no sex differences in our primary outcomes, the sample size of females was disproportionately lower than the males. This is consistent with an ongoing problem in the stroke recovery research field, where females are often underrepresented and understudied, and where females who experience higher levels of impairment are less likely to participate in research.

Female proportion has a stronger influence on dispersal than body size in nematodes of mountain lakes.

Nematodes disperse passively and are amongst the smallest invertebrates on Earth. Free-living nematodes in mountain lakes are highly tolerant of environmental variations and are thus excellent model organisms in dispersal studies, since species-environment relationships are unlikely to interfere. In this study, we investigated how population or organism traits influence the stochastic physical nature of passive dispersal in a topologically complex environment. Specifically, we analyzed the influence of female proportion and body size on the geographical distribution of nematode species in the mountain lakes of the Pyrenees. We hypothesized that dispersal is facilitated by (i) a smaller body size, which would increase the rate of wind transport, and (ii) a higher female proportion within a population, which could increase colonization success because many nematode species are capable of parthenogenetic reproduction. The results showed that nematode species with a low proportion of females tend to have clustered spatial distributions that are not associated with patchy environmental conditions, suggesting greater barriers to dispersal. When all species were pooled, the overall proportion of females tended to increase at the highest elevations, where dispersal between lakes is arguably more difficult. The influence of body size was barely relevant for nematode distributions. Our study highlights the relevance of female proportion as a mechanism that enhances the dispersal success of parthenogenetic species, and that female sex is a determining factor in metacommunity connectivity.

Shifting goalposts: widening discrepancies between girls' actual and ideal bodies predict disordered eating from preadolescence to adulthood.

Little is known regarding how disordered eating (DE) relates to perceived actual body size, ideal body size, and their discrepancy. This study examined changes in perceived actual body size, ideal body size, and actual-ideal discrepancies over time, and their relationship with subsequent DE. Participants were 759 female twins from the Minnesota Twin Family Study who reported on body image and DE every three to five years between approximately ages 11 to 29. We used multilevel modeling to examine developmental trajectories of body mass index (BMI) and Body Rating Scale Actual, Ideal, and Actual-Ideal discrepancy scores and compared the degree to which BMI, BRS body size perceptions, and body dissatisfaction predicted DE behaviors and attitudes over time. Participants were treated as singletons in analyses. Perceived Actual body sizes and BMIs increased from age 10 to 33, whereas Ideal body sizes remained largely stable across time, resulting in growing Actual-Ideal discrepancies. Body size perceptions and Actual-Ideal discrepancies predicted subsequent DE behaviors and attitudes more strongly than did body dissatisfaction as measured by self-report questionnaires. This research advances understanding of how female body size perceptions and ideals change across development and highlights their relationship with subsequent DE.

Influence of prey availability on the movement pattern of breeding saker falcons (Falco cherrug) in Mongolia

Abstract As an apex predator in arid steppe, saker falcon plays a crucial role in maintaining ecosystem balance. Understanding their movement patterns concerning conspecific competition and prey availability is important for their conservation. We aim to understand how movement pattern of breeding saker falcons relates to prey availability. Twelve adult sakers were tracked during the breeding seasons, using satellite transmitters. Throughout the breeding season, sakers exhibited territorial behaviour, with minimal overlap in range use among neighbouring conspecifics. Males occupied larger areas (mean = 2,397 ha, median = 1,221 ha), compared to females (mean = 1,241 ha, median = 554 ha), and it remained consistent throughout breeding season. Female home range size increased notably during late nestling stage and post-fledging dependence periods, indicating release from brooding constraints. Notably, we found a negative relationship between male home range size and prey availability. In high rodent density areas, males occupied smaller areas (mean = 1,135 ha, median = 1,034 ha), contrasting with low rodent density areas (mean = 6,815 ha, median = 6,516 ha). However, no significant relationship was observed between female home range size and prey availability. We also noted instances of nest abandonment and early dispersal behaviour in some females, potentially influenced by a handicapping effect of tagging. Our findings offer valuable insight into how prey availability shapes saker falcon space use and defines their spatial requirements for successful breeding. This knowledge is crucial for the conservation and management of globally endangered saker falcons, informing targeted habitat protection and resource management strategies.

Diet, sexual dimorphism, and fertility aspects of Melanophryniscus fulvoguttatus (Mertens, 1937) from Central-East Brazil

Melanophryniscus fulvoguttatus is a small toad that inhabits the Cerrado, Atlantic Forest, and humid Chaco of South America. Due to its aposematic coloration and behavior, it is a species that may present chemical defenses such as alkaloids and a restricted diet similar to other species of the genus. Although it was described in the early 20th century, there is still little information on its natural history and ecology. Here, we described the diet, tested the sexual dimorphism, and calculated the fertility index of M. fulvoguttatus based on a sample of eight males and 21 females from a population within the Cerrado. Sexual dimorphism was assessed using 15 morphometric measures; diet was calculated as an index of relative importance by prey item and tested for sex differences; fertility was tested for relations between body size and the number of eggs; and we also estimated the reproductive investment. Our results demonstrate that this population’s diet consisted mostly of ant species, with Pheidole radoszkowskii being the most important, followed by Crematogaster sp. and Cyphomyrmex transversus. Regarding sexual dimorphism, we observed that females were significantly larger than males, with a positive relationship between female size and the number of eggs. We did not find significant differences in the diets of males and females. Although the diet and reproductive aspects of M. fulvoguttatus are similar to those of its congeneric species, further studies are needed in order to address the relationship between the species diet and its chemical defenses.