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People often interact with groups (i.e., ensembles) during social interactions. Given that group-level information is important in navigating social environments, we expect perceptual sensitivity to aspects of groups that are relevant for personal threat as well as social belonging. Most ensemble perception research has focused on visual ensembles, with little research looking at auditory or vocal ensembles. Across four studies, we present evidence that (i) perceivers accurately extract the sex composition of a group from voices alone, (ii) judgments of threat increase concomitantly with the number of men, and (iii) listeners sense of belonging depends on the number of same-sex others in the group. This work advances our understanding of social cognition, interpersonal communication, and ensemble coding to include auditory information, and reveals peoples ability to extract relevant social information from brief exposures to vocalizing groups.

Infanticide and adoption have been attributed to sexual selection, where an individual later reproduces with the parent whose offspring it killed or adopted. While sexually selected infanticide is well known, evidence for sexually selected adoption is anecdotal. We report on both behaviors at 346 nests over 27 y in green-rumped parrotlets (Forpus passerinus) in Venezuela. Parrotlets are monogamous with long-term pair bonds, exhibit a strongly male-biased adult sex ratio, and nest in cavities that are in short supply, creating intense competition for nest sites and mates. Infanticide attacks occurred at 256 nests in two distinct contexts: 1) Attacks were primarily committed by nonbreeding pairs (69%) attempting to evict parents from the cavity. Infanticide attacks per nest were positively correlated with population size and evicting pairs never adopted abandoned offspring. Competition for limited nest sites was a primary cause of eviction-driven infanticide, and 2) attacks occurred less frequently at nests where one mate died (31%), was perpetrated primarily by stepparents of both sexes, and was independent of population size. Thus, within a single species and mating system, infanticide occurred in multiple contexts due to multiple drivers. Nevertheless, 48% of stepparents of both sexes adopted offspring, and another 23% of stepfathers exhibited both infanticide and long-term care. Stepfathers were often young males who subsequently nested with widows, reaching earlier ages of first breeding than competitors and demonstrating sexually selected adoption. Adoption and infanticide conferred similar fitness benefits to stepfathers and appeared to be equivalent strategies driven by limited breeding opportunities, male-biased sex ratios, and long-term monogamy.

At wintering sites of the migratory Short-eared Owl (Asio flammeus) in subtropical Asia, behavioral interactions between males and females are limited, and the body mass and plumage features between the sexes overlap significantly. Thus, sexing the species morphometrically for research and conservation activities is difficult. We aimed to develop a quantitative method for sexing Short-eared Owls, and we here present a new formula to do so using plumage features. We used a total of 198 Short-eared Owls (163 from bird rescue efforts at 15 airports and 35 preserved specimens from a museum in Taiwan) and carefully examined their morphological data and plumage images, then determined their sex using polymerase chain reactions of chromodomain helicase DNA-binding protein genes on sex chromosomes or gonad inspection. Eight of the ten traits we evaluated differed significantly between males and females. Females had a greater number of cross bars on primaries, secondaries, and outermost tail feathers; a higher proportion of yellowish-brown underwing coverage; and larger measurements in head length, bill length, tarsus length, and body mass. The best-fit model suggested simplifying the formula to just the proportion of the yellowish-brown underwing coverage, which provided sexing accuracy exceeding 95.9% for the 49 live individuals in the test data set and 94.3% for the 35 preserved specimens. This formula addresses the challenges posed by ambiguous individuals in the wintering region and offers an efficient and accurate means for sexing Short-eared Owls when DNA or gonad inspection is unavailable. [ABSTRACT FROM AUTHOR]

I examined 107 shining cuckoos that died accidentally in the northern North Island, New Zealand, during 39 years. Birds arriving on migration in spring were all in adult plumage. Juveniles occurred mainly from January to March. The sex-ratio of adults was 1:1. In several measurements, females were slightly larger than males on average, and adults slightly larger than juveniles. Gonad size suggested readiness for breeding from September to January (inclusive). Ninety-one gizzards held a total of 3754 arthropod food items. Insects (10 orders) made up around 94% of items and just two orders accounted for 79% of food items: caterpillars (larval Lepidoptera, 55%) and beetles (Coleoptera, 24%). 'Spiny' caterpillars made up roughly 8% of total caterpillars. Ladybirds (Coccinellidae) made up 21% of beetles. Shining cuckoos ate small prey, mostly 1–10 mm long (44%) and 11–20 mm long (43%). By eating hairy caterpillars and ladybirds, shining cuckoos exert predatory control on insects that other birds avoid. By gorging (up to 258 insects per stomach) the cuckoo might dampen the impact of herbivorous insects (e.g. caterpillar infestations) on plants. [ABSTRACT FROM AUTHOR]

The catch of butterfly kingfish Gasterochisma melampus, a large pelagic species in southern temperate waters, is strongly biased (73%) towards females. Whether this is caused by differences in sex-specific spatiotemporal distributions or mortality of sexes is investigated herein. Analysis of sex ratios using a generalized additive model (GAM) for year, month, latitude, longitude, sea surface temperature, and fork length from Japanese longline catch data for areas where immature and adult fish occur revealed the influence of space and time on sex ratios to be small, and that of fork length to be large. Based on observation of the increments in vertebrae of immature fish (N = 179), the fork length at the time of increment formation was back-calculated from distances between increments on the anterior and posterior cones, generating 2–8 measurements per vertebra and 865 data points in total. Growth equations were calculated for each sex, with females growing faster. The age composition of males and females in the catch was similar, meaning that the mortality rate in males is unlikely to be higher than that of females. The data suggest that biased sex ratios in catches are representative of the natural sex ratio in a population for fish more than 60 cm in fork length. [ABSTRACT FROM AUTHOR]

Accurate identification of agricultural pests is a major component of integrated pest management. The seedcorn maggot, Delia platura (Meigen) (Diptera: Anthomyiidae), is a cosmopolitan polyphagous pest species that may be found in high numbers in numerous crops. Two morphologically identical genetic lines of D. platura (H and N) with distinct distributions were recently identified. To date, no study has investigated the reproductive compatibility of the two lines and thus the possibility that they may actually be two unique biological entities. A previous study described the reproductive traits of the two lines and suggested that H‐line females are highly selective toward the male with which they mate, pointing to a possible pre‐mating isolation mechanism between the lines. Using laboratory‐reared colonies originating from the Montérégie region in Québec, Canada, this study investigates the reproductive compatibility of the two D. platura lines. We found that only one of 30 H‐line females was inseminated by an N‐line male, further suggesting mate choice as a pre‐mating isolation mechanism between the lines. However, N‐line females were readily inseminated by H‐line males, suggesting a lack of pre‐mating isolation in this type of cross. The eggs laid by N‐line females mated with H‐line males had a lower hatching rate than the ones laid by females of intraline crosses, suggesting either post‐mating pre‐zygotic or post‐zygotic partial isolation. However, the larvae that did hatch had a comparable developmental success to those from intraline crosses in terms of survival and developmental time from larval hatching to adult emergence, pupal mass, and adult sex ratio, suggesting a lack of post‐zygotic isolation for these life stages. Considering the different biological traits of the two lines, we suggest the use of the 'biotype' terminology to designate the two biological entities and discuss their implications for integrated pest management. [ABSTRACT FROM AUTHOR]

The strength and direction of sexual selection can vary among populations. However, spatial variability is rarely explored at the level of the social group. Here we investigate sexual selection and sex roles in the paternally mouthbrooding, socially monogamous, and site-attached pajama cardinalfish, Sphaeramia nematoptera. Females were larger and more aggressive and had a longer dorsal fin filament, indicating reversed sex roles. At the scale of social groups, we show that the Bateman gradient and reproductive variance depend on the sex ratio and size of groups. In small and medium-sized groups with balanced or male-biased sex ratios, Bateman gradients were steeper for females, whereas gradients were equally steep for both sexes in large groups or when the sex ratio was female biased. For both sexes, reproductive variance increased with group size and with a higher male-to-female sex ratio. In S. nematoptera , mating opportunities outside the socially monogamous pair appear to impact sexual selection. We conclude that strength and direction of sexual selection can be masked by social dynamics in group-living species when considering only population and large-scale demographic processes. [ABSTRACT FROM AUTHOR]

One of the selective advantages of delayed implantation in carnivores is the flexibility to decouple the time between mating and parturition, allowing both to occur when conditions are most favorable. Terrestrial carnivores with delayed implantation have evolved reduced maternal energy expenditure through shorter gestation length, smaller neonates, and smaller litters, with a possible linkage between maternal body condition and time of birth or litter size. Using data on wolverine (Gulo gulo) females and cubs from management removals covering the entire latitudinal gradient of the Scandinavian population in 2001‐2022, I assessed the effect of extrinsic and intrinsic factors on variation in parturition date and litter size. Timing of parturition varied over 2 months, where 90% of the litters were born between 5 February and 11 March, with a birth peak on 23 February. Females living in winter grazing pastures of semi‐domestic reindeer (Rangifer tarandus) gave birth earlier than those outside, and along an elevation gradient parturition date was delayed at higher altitudes. I did not find evidence of an effect of latitude on parturition date. Furthermore, older females had greater odds than younger females of having litters with 3 cubs rather than 1 cub. To minimize the risk of harvesting lactating females, management regulations should implement harvest seasons that extend no longer than the end of January. [ABSTRACT FROM AUTHOR]

The MR-induced gradient artifact affects EMG recordings during simultaneous muscle BOLD/EMG acquisitions. However, no dedicated hardware can remove the gradient artifact easily, and alternative methods are expensive and time-consuming. This study aimed to develop three denoising methods requiring different processing levels and MR-compatible hardware. At two time points, surface EMG was recorded from the lower leg of 6 participants (50:50 sex ratio, age = 26.24.6 yrs., height = 173.59.2 cm, weight = 71.511.4 kg) using a plantar flexion-based block design consisting of 30s of rest followed by 30s of flexion for 5 min, under three conditions: inside the MRI bore, with and without a BOLD sequence (3 T, BOLD sequence, GRE EPI, 10 slices, 64×64 matrix, 2 mm thickness, and TE/TR/flip = 35/3000 ms/70), and outside the MRI environment. Simultaneous BOLD/EMG recordings were denoised using average artifact subtraction with three methods of artifact template creation, each having varying timing and hardware requirements. Method M1 builds the artifact template by recording the scanner triggers coming from the MRI; M2 creates the artifact template with a constant artifact period computed as TR/[number of slices]; M3 estimates the artifact template by looking at the periodicity of the gradient artifact located in the EMG recordings. Following postprocessing, SNR analysis was performed, comparing rest-to-flexion periods, to assess the efficacy of denoising methods and to compare differences between conditions. Linear mixed-effects models showed no significant differences in the mean SNR between denoising methods (p = 0.656). Furthermore, EMG SNR measurements were significantly affected by the magnetic environment (p < 0.05) but not by muscle fatigue over time (p = 0.975). EMG recordings contaminated with gradient artifacts during simultaneous BOLD/EMG can be efficiently denoised using all proposed methods, with two methods requiring no extra hardware. With minimal post-processing, EMG can easily be performed during muscle BOLD MRI studies. [ABSTRACT FROM AUTHOR]

Enhalus acoroides (L.f.) Royle is a large and important foundation seagrass species in the tropical Indo-Pacific. The northern marginal populations in China have been declining over the last decades. The reproductive phenology and fruit set of this dioecious seagrass were investigated from June 2017 to February 2018 in two areas in Li'an lagoon, Hainan Island, China. We found that E. acoroides flowered year-round. However, the flowering intensity varied among seasons and was highest in the summer and lowest in the winter. The shoot sex ratio was male-biased, and the pollen-ovule ratio was approximately 104: 1, based on the sex ratio and the number of male florets per inflorescence. Female and male plants flowered at the same time in this population. Despite the high reproductive investment in terms of flower formation observed throughout the year, the abundance of the mature fruits was low, possibly due to physical disturbance and cover by epiphyte and algae. This study provides insight into the reproductive ecology of E. acoroides, which will be useful for the future conservation of this threatened seagrass. [ABSTRACT FROM AUTHOR]

Present study describes the reproductive cycle, sex ratio, stages of the gonadal development and gonadal index (GI) of Conus coronatus collected from Buleji and Manora, Karachi. A total of 641 (329 from Manora and 312 from Buleji) C. coronatus of different sizes had randomly collected from April 2015 to March 2016. The females showed predominance in the population at both sites. Five different stages of the reproductive cycles of male and female C. coronatus: resting, developing, ripe, partially spawned, and spawned out were found. Spawning was observed throughout the year. At resting phase all the stages of spermatogenesis and oogenesis were absent. At developing stage oogonia, oocytes, spermatogonia, and spermatocytes were abundantly present in their respective follicles. At ripe stage, in males follicle countless spermatids and spermatozoa were observed however, in female the vitellogenic oocytes were been packed in follicles. At partially spawned stage, male follicles were partially empty while in female follicles unspawned mature ova were seen. At spawned out stage, both male and female follicles were empty. Gonadal development in males was at its highest peak (4.37) in summer (September 2015) at Manora and (4.00) in summer and winter (May 2015 and February 2016) at Buleji. However, in females, the highest value (5.00) of GI was observed only in summer (July and October 2015) at Manora and (4.36) in September (2015) at Buleji. [ABSTRACT FROM AUTHOR]

Striostrea prismatica is an oyster of commercial importance present in several locations of the Eastern Tropical Pacific. The objective of this study was to evaluate the sex ratio, gametogenic cycle, maturity stages, size at first maturity (SH50) and monthly variation in the condition index of this species over the course of an annual cycle on the coast of Colima, Mexico. The oysters found in the shallow sublittoral areas near Faro de Campos were larger and heavier than those in Cuyutlan lagoon. The sex ratio was significantly shifted towards males at both sites. The gonad showed a prolonged undifferentiated stage lasting from November to April, a spawning period limited to June through October and an extended post-spawning period from August to December. SH50 was higher in females in the lagoon as well as in the shallow sublittoral. Monthly variation in surface temperature and chlorophyll a in both study areas only correlated with the condition index of populations in the shallow sublittoral and inner lagoon in the months of lowest temperatures and highest chlorophyll a. These findings provide basic information on the reproductive cycle of rock oysters that may prove useful for the development of improved harvesting practices in the study region. [ABSTRACT FROM AUTHOR]

Introduction Methods Results Discussion We aimed to assess: (i) trends in alcohol‐specific — that is, fully attributable — morbidity and mortality in the German adult population aged 15–69 between 2000 and 2021; and (ii) changes in alcohol‐attributable disease burden — that is, fully and partially alcohol‐attributable categories — for 2006, 2012, 2018 and 2021.Morbidity data was pulled from hospitalisation and rehabilitation statistics and mortality data was pulled from the causes of death registry. Alcohol use, adjusted for unrecorded consumption, was estimated using the Epidemiological Survey of Substance Abuse and triangulated with per capita consumption from annual sales data. For major disease categories, alcohol‐attributable fractions were estimated for males and females by age groups (15–29, 30–49, 50–69 years) using the comparative risk assessment methodology.For males and females, the age‐standardised rate of alcohol‐specific morbidity peaked in 2012 and decreased thereafter showing a steep decline from 2019 to 2021. The rates of alcohol‐specific mortality decreased constantly from 2000 to 2019 but increased from 2019 to 2021. Compared to 2006 the age‐standardised alcohol‐attributable morbidity and mortality rates in males and females were lower in 2021. For both sexes, the age‐standardised alcohol‐attributable morbidity and mortality rates and the proportions of morbidity/mortality rates relative to all‐cause morbidity/mortality decreased between 2006 and 2021.The declines in alcohol‐attributable morbidity and mortality are in line with decreases in consumption and signal that the importance of alcohol in health service utilisation and mortality has weakened. Sex ratios in morbidity and mortality do not indicate a strong converging trend. [ABSTRACT FROM AUTHOR]

Understanding the reproductive ecology of crustaceans is important for developing appropriate resource management policies. Because the demand for sand crabs (Ovalipes punctatus) as a food resource has recently surged in Korea, their reproductive ecological characteristics should be comprehensively described. In this study, the reproductive ecological characteristics—sex ratio, female gonad maturity, abdominal width (AW), condition factor (K), and gonadosomatic index (GSI)—of individuals of O. punctatus collected from the Yellow Sea in Korea (35°15′00″N, 125°15′00″E) from January to December 2021 were examined. Based on the sex ratio (1:1.61, females:males), we determined that males were more abundant than females. The monthly K for both the males and females reached its maximum in April. The monthly GSI revealed that the males were most numerous in December, whereas the females were most abundant in May. The GSI graph indicates that the main spawning season of O. punctatus is from May to July. The AW and GSI of the females increased as their gonads matured; based on this correlation, the maturity of female individuals can be determined by examining the abdominal flap morphology. The results of histological analysis indicated that females of O. punctatus exhibit synchronous development, by which oocytes develop simultaneously. Furthermore, the size at maturity, at which more than half of the individuals participated in spawning, was 75.6 mm. The findings of this study contribute to the development of policies for the sustainable fisheries of O. punctatus. [ABSTRACT FROM AUTHOR]

A total of 332 freshwater crab Sartoriana spinigera samples were collected for eight consecutive months from the Ratargul freshwater swamp forest, Bangladesh, to examine their general morphometrics and reproductive traits. The length‐weight relationships of carapace weight with carapace length, width, and depth indicated negative allometric growth. The logarithmic relationship between carapace weight and carapace length, carapace weight and carapace width, and carapace weight and carapace depth exhibited a correlation value of 0.86, 0.79, and 0.56, respectively. Fulton's condition factor and allometric condition factor were found to be highest in March and lowest in October. The sex ratio was 1.59 : 1 for the male to female, which did not show a considerable divergence from the expected 1 : 1 ratio in the chi‐square test (P < 0.05). In July, a maximum of mature individuals was collected and investigated. The fertilization was 1297 ± 629 ova, the ovary weight was 447.22 ± 359.39 mg, and the egg diameter was 375.15 ± 130.18 µm. Histological analysis showed that the male hepatopancreas was well organized and decomposition was reported in the female during the vitellogenic stages of the ovary. Spermatogonium cells were found in the male gonad, and cells from the female gonad were in the vitellogenic mature stage. In conclusion, the research will serve as a foundation for future research work on freshwater crab species as well as the conservation and maintenance of the ecological balance of this species in the Ratargul freshwater swamp forest. [ABSTRACT FROM AUTHOR]

Aedes albopictus (Skuse, 1895), the Asian tiger mosquito extended globally in just a few decades from Asia showing great adaptability despite temperature-dependent development. The present study revealed the effects of temperature (20 ℃, 26 ℃, 30 ℃, and 35 ℃) on various developmental parameters of Ae. albopictus strains belonging to the desert (Jodhpur, Rajasthan) and the coastal (Kolkata, West Bengal) regions of India. The desert strain developed faster from eggs-adult emergence (7.5 days at 35 ℃ and 14.0 days at 20 ℃) than the coastal strain (7.8 days at 35 ℃ and 16.8 days at 20 ℃). The survival was highest and lowest at 26 °C and 35 ℃, respectively, irrespective of strains and stages. The larval survival trends of both strains were similar to pupae across the temperature range. The wing length of the desert strain was shorter in comparison to the coastal strain. Wing length was found inversely proportional to the temperature being longest at 20 ℃ and the shortest at 35 ℃ for both strains. Male and female wing lengths were larger (25% and 22.7% in the Jodhpur strain and 24.6% and 23.6% in the Kolkata strain) at 20 ℃ compared to 35 ℃, respectively. Significant differences were observed between the male-female sex ratio in the coastal strain. The outcomes of the study suggest consideration of temperature impact on immature developmental attributes that might help in the refining of control measures and a better understanding of ecological adaptations in contrast to ecological conditions. [ABSTRACT FROM AUTHOR]

Species experience a variety of environmental and anthropogenic conditions across their ranges leading to spatial variation in population dynamics. Understanding population dynamics under different conditions is important but it is challenging to allocate limited effort to spatial and temporal subpopulation monitoring. Using GLMMs, we analyze survey data of a metapopulation of coconut crabs spanning 7 years and 15 sites in and near the Pemba archipelago, Zanzibar, to estimate trends in population size (based on catch per unit effort), weight and sex ratio at the meta‐ and subpopulation level and investigate anthropogenic drivers of these trends. We found that the overall metapopulation has remained stable in terms of size and composition over the survey period, but observed diverging trends in population size and sex ratio at some subpopulations. Formal protection of sites was associated with positive population trends. Of nine sites for which we could estimate site‐specific trends, three showed increasing and two decreasing trends, whereas four sites had stable subpopulations. Although anthropogenic factors affected the average weight, and the incidence of small and large individuals, we found no temporal trends in any weight‐related measures. Furthermore, there were no apparent patterns between weight‐related measures and subpopulation trends. The metapopulation was biased toward males, and exploitation appeared to be associated with declining trends in the proportion of females, likely an artifact of a strong decline in the proportion of females in one of only two exploited sites in the dataset. Educational campaigns implemented in 2020 at six sites were not related to higher population sizes in later surveys. The variable trends in subpopulation sizes and composition highlight the need for spatially replicated monitoring in metapopulations. The analyses further provide a detailed baseline for future subpopulation studies of this vulnerable species in one of its last remaining metapopulations in the Western Indian Ocean. [ABSTRACT FROM AUTHOR]

Population dynamics are driven by stochastic and density‐dependent processes acting on demographic rates. Individuals differ demographically, and to capture these differences, models of population dynamics are usually structured by age and stage, rarely by sex. An effect of sex on population dynamics is expected if the dynamics of males and females differ, requiring an unequal sex ratio at birth and/or sex‐specific survival probabilities. Goshawks (Accipiter gentilis) show large sexual size dimorphism and differential survival, but it is unknown whether males and females contribute differently to population dynamics. We studied a goshawk population in northern Germany over 47 years using brood monitoring data, collected feathers and nestling ringing data. We jointly analyzed the data using a two‐sex integrated population model and performed retrospective and prospective population analyses to understand whether the demographic drivers of population change differ between the sexes. The population showed large fluctuations, during which the number of breeding pairs doubled, but the long‐term trend of the population was slightly negative. Female survival exceeded male survival during the first year of life. Females started to reproduce at a younger age than males, productivity increased with female age, the sex ratio of nestlings was male biased and there was moderate male immigration. Despite these differences, temporal variation in sex ratio did not contribute to population dynamics and the contribution of temporal variation in survival was similar for both sexes. Variation in first‐year survival was the strongest driver in this population, regulated by a weak density‐dependent feedback acting through female first‐year survival. Overall, the contributions of the two sexes to population dynamics were similar in this monogamous species with strong sexual size dimorphism. [ABSTRACT FROM AUTHOR]

The coalescent is a stochastic process representing ancestral lineages in a population undergoing neutral genetic drift. Originally defined for a well-mixed population, the coalescent has been adapted in various ways to accommodate spatial, age, and class structure, along with other features of real-world populations. To further extend the range of population structures to which coalescent theory applies, we formulate a coalescent process for a broad class of neutral drift models with arbitrary – but fixed – spatial, age, sex, and class structure, haploid or diploid genetics, and any fixed mating pattern. Here, the coalescent is represented as a random sequence of mappings C = C t t = 0 ∞ from a finite set G to itself. The set G represents the "sites" (in individuals, in particular locations and/or classes) at which these alleles can live. The state of the coalescent, C t : G → G , maps each site g ∈ G to the site containing g 's ancestor, t time-steps into the past. Using this representation, we define and analyze coalescence time, coalescence branch length, mutations prior to coalescence, and stationary probabilities of identity-by-descent and identity-by-state. For low mutation, we provide a recipe for computing identity-by-descent and identity-by-state probabilities via the coalescent. Applying our results to a diploid population with arbitrary sex ratio r , we find that measures of genetic dissimilarity, among any set of sites, are scaled by 4 r (1 − r) relative to the even sex ratio case. [ABSTRACT FROM AUTHOR]

Biased sex ratios among reproductive individuals are common in plants, but the underlying mechanisms, as well as the evolutionary consequences, are not well understood. The classical theory of Düsing and Fisher predicts an equal primary sex ratio at seed production, based on the selective advantage of the rare sex. Biased sex ratios among reproductive plants can arise from sexual dimorphism in survival and flowering. Sex ratio biases can also be present from the seed stage; in these cases, assumptions of Düsing's and Fisher's theory, for example, random mating or demographic equilibrium, are thought to be violated.We investigated mechanisms leading to female‐biased sex ratios in the arctic‐alpine dwarf willow Salix herbacea L. We studied sex ratios in three natural populations over 3 years as well as in 29 crosses (full‐sib families) under controlled conditions over four growth periods. We tested whether sex ratio was associated with habitat parameters (elevation and snowmelt time), or with germination, survival or flowering, and whether females and males differed in size or flowering that may cause observation bias.We detected a strong and consistent female bias, both in natural populations (sex ratio [proportion of females]: 0.71–0.82) and in our controlled experiment (overall sex ratio: 0.70–0‐72). Female bias became more pronounced with increasing elevation. Our data did not support sexual dimorphism in size or flowering. Family sex ratios varied largely (from 0.25 to 1), including many female‐biased families, unbiased families and two male‐biased families. Families with lower germination, seedling establishment, survival or flowering did not have stronger female bias, indicating that intrinsically higher survival or flowering in females does not explain overall female bias.Synthesis. Our results suggest that sex ratio bias in S. herbacea is already present in seeds and does not arise through intrinsic differences between sexes. Candidate mechanisms that can lead to both overall female bias and variation in sex ratio among families are meiotic drive or cyto‐nuclear interactions. The pioneer habit of Salix may lead to non‐equilibrium population dynamics that allow for the long‐term persistence of variable genetic sex ratio distortion systems that arise from genetic conflict. [ABSTRACT FROM AUTHOR]

Simple Summary: To better inform nilgai antelope management decisions, basic life history data are needed. We collected reproductive tracts of free-ranging female nilgai from 2018 to 2021 in Southern Texas. We found high pregnancy and twinning rates. Moreover, we found nilgai as young as 1 year old to be pregnant and nilgai as old as 12 years old to be pregnant. Our findings demonstrate the high reproductive potential of free-ranging nilgai in Southern Texas. To prevent nilgai overpopulation and associated damage to the land, harvest management strategies should be used, particularly in introduced areas where there are no natural predators. Free-ranging nilgai antelope (Boselaphus tragocamelus) are an understudied species, both on their native ranges of India, Pakistan, and Nepal and on their introduced ranges in southern Texas. Basic data related to population sizes, survival, reproduction, and recruitment are needed throughout their range to inform management and conservation decisions. We collected nilgai fetuses from 3 ranches in southern Texas, including East Foundation's El Sauz and Santa Rosa ranches, and the Norias Division of the King Ranch® from 2018–2021. We calculated the percentage of individuals that were pregnant in each of the sample years and overall. We determined monthly average, maximum, and minimum fetus length. Of 488 nilgai cows, we found 386 to be pregnant (79%) and 214 to be pregnant with twins (56%). We found nilgai cows as young as 1-year old to have fetuses and therefore to have reached sexual maturity. Sex ratios of fetuses during any sampling year did not differ. We found ample evidence supporting our hypothesis that nilgai are fecund on their introduced range of southern Texas. To prevent nilgai overpopulation and associated problems, harvest management strategies should be implemented, specifically on nilgai cows. [ABSTRACT FROM AUTHOR]

Pollinating fig wasps are believed to adjust their sex ratios according to standard local mate competition (LMC) theory.Standard LMC theory assumes that all mothers ovipositing in a patch or fig does so simultaneously. However, it has been shown that fig wasps can oviposit sequentially.We counted the number of figs containing dead and living mothers in figs where mothers entered naturally to estimate the incidence of sequential and simultaneous oviposition.Single mothers were the norm in two wasp species, and multiple mothers the norm in the other two. However, contrary to LMC theory, in all four species, when multiple mothers occurred, sequential oviposition seems to occur more frequently than simultaneous oviposition.The sex allocation problem fig wasp mothers face is thus more complicated than the widely assumed simultaneous ovipositing situation, and it leads to several expectations. Single mother's sex ratios should increase as the probability of additional mothers increases. Naturally founded multi‐mother figs should have more female‐biased sex ratios than the standard LMC model predicts for the final number of mothers. This is because early‐arriving mothers underestimate the number of mothers and lay more daughters than the final number of mothers would require and later‐arriving mothers can lay fewer sons to be competitive against the first mothers' too female‐biased clutches.Mothers must produce sex ratios that are optimised across a probabilistic range of foundress densities they experience. [ABSTRACT FROM AUTHOR]

Offspring sex ratios may deviate from parity when the fitness benefits of producing male or female offspring vary. We tested for sex ratio bias in smooth‐billed anis Crotophaga ani, a communal laying cuckoo with low within‐group relatedness and high offspring dispersal. One male group member performs nocturnal incubation and sires more offspring than other males in the group, suggesting males may have greater reproductive variance than females. We hypothesized that pre‐breeding rainfall influences food availability and offspring sex ratio, predicting that breeding females skew production towards the sex with higher reproductive variance (males) in high food years. Females may also adjust sex ratio across the hatching order to increase survival of the more competitive sex, especially when clutches are larger and within‐brood competition is higher. As adults, male smooth‐billed anis are larger than females, so we assumed male nestlings are more competitive than females and predicted a male‐bias in first hatched chicks in larger broods. Contrary to our first prediction, offspring sex ratio was male biased when pre‐breeding rainfall was lower. In partial support of our second prediction, marginally more first hatched chicks were male in larger broods. To our knowledge, this is the first evidence of offspring sex ratio bias in a communal laying bird species. Future work in this system will attempt to uncover the mechanisms by which co‐breeding females adjust offspring sex ratio and test alternative hypotheses to explain male‐biased offspring sex ratios under different conditions. [ABSTRACT FROM AUTHOR]

Background: Prior studies have indicated that female individuals outnumber male individuals for certain types of dystonia. Few studies have addressed factors impacting these sex differences or their potential biological mechanisms. Objectives: To evaluate factors underlying sex differences in the dystonias and explore potential mechanisms for these differences. Methods: Data from individuals with various types of dystonia were analyzed in relation to sex. Data came from two different sources. One source was the Dystonia Coalition database, which contains predominantly idiopathic adult‐onset focal and segmental dystonias. The second source was the MDSGene database, which contains predominantly early‐onset monogenic dystonias. Results: The 3222 individuals from the Dystonia Coalition included 71% female participants and 29% male participants for an overall female‐to‐male ratio (F:M) of 2.4. This ratio varied according to body region affected and whether dystonia was task‐specific. The female predominance was age‐dependent. Sex did not have a significant impact on co‐existing tremor, geste antagoniste, depression or anxiety. In the 1377 individuals from the MDSGene database, female participants outnumbered male participants for some genes (GNAL, GCH1, and ANO3) but not for other genes (THAP1, TH, and TOR1A). Conclusions: These results are in keeping with prior studies that have indicated female individuals outnumber male individuals for both adult‐onset idiopathic and early onset monogenic dystonias. These results extend prior observations by revealing that sex ratios depend on the type of dystonia, age, and underlying genetics. [ABSTRACT FROM AUTHOR]

Sex differences in early‐life survival can drive skewed adult sex ratios (ASR), which play an important role in mating tactics and parental sex roles. Among birds, cuckoos exhibit the largest diversity in mating systems and thus represent an interesting system to study sex‐specific demography.Here we investigate the early‐life survival pathways shaping ASR using long‐term field data and sex‐ and stage‐specific demographic modelling of black coucals and white‐browed coucals—two sympatric Centropus cuckoo species differing in mating system and the extent of sexual size dimorphism.We hypothesized that sexual size dimorphism would lead to differential juvenile mortality due to the greater energy demands and predation risk of the larger sex during maturation. We expected higher early‐life mortality among large‐bodied females in the sexually dimorphic and classically polyandrous black coucal, whereas no bias should exist in the less dimorphic and monogamous white‐browed coucal.Both species had balanced hatching sex ratios, but in black coucals, female survival (μ = 0.64 ± 0.061 SD) was lower during the 'groundling' phase (i.e. a flightless 3‐week period following nest departure) than male survival (0.70 ± 0.066). Yet, this sex difference in survival was not strong enough to account for the species' male‐biased ASR where 70% of the adult population is male. In white‐browed coucals, survival during maturation exhibited high inter‐individual variation but lacked clear sex differences, reflecting the emergence of a balanced ASR.In summary, we found no evidence that the strongly male‐biased ASR of black coucals is driven by sex‐specific survival during maturation. In black coucals, the male‐biased ASR must therefore stem from processes occurring later in life: possibly, larger females are more likely to die during migration and/or the recruitment of young females is delayed due to competitive exclusion by more experienced females.Our results differ from studies on shorebirds, in which sex‐specific mortality of precocial young is related to ASR and mating dynamics. Hence, early‐life sex biases in survival of precocial shorebirds cannot be generalized to other taxonomic groups.Factors other than early‐life sex biases in survival are likely to be important in shaping adult sex ratios and the associated mating dynamics and social behaviours in altricial coucals. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

California halibut (Paralichthys californicus) is a candidate species for aquaculture and stock enhancement. These applications rely on sex control, either to maximize the production of faster growing females or to match sex ratios in the wild. Other paralichthids exhibit temperature‐dependent sex determination (TSD), but the presence and pattern of TSD is not well defined in California halibut. Juvenile California halibut were cultured at three distinct temperatures (15°C, 19°C, and 23°C) through the developmental period presumed to be thermosensitive based on findings from congeners. Sex ratios were quantified in each treatment using phenotypic sex identification techniques applied early (molecular biomarkers; 51–100 mm total length [TL]) and late (visual examination of the gonads; ≥100 mm TL) in the juvenile phase. Both techniques indicated similar sex determination trends at each temperature, with overall sex ratios assessed as 49.9% male at 15°C, 74.5% male at 19°C, and 98.2% male at 23°C. Growth rates were highest at 23°C and lowest at 15°C, with intrinsically fast‐ and slow‐growing individuals at all temperatures. At 15°C and 19°C, females comprised a higher proportion among the fast growers than they did among the slow growers. These data show that California halibut exhibit TSD, with temperatures of 19°C and 23°C masculinizing fish while 15°C appears to produce a 1:1 sex ratio. This study will help optimize sex ratios and growth in hatcheries through thermal manipulation. Furthermore, the developed biomolecular tools and identified temperature thresholds will be important in future work to understand the influence of global warming on wild population demographics. Research Highlights: California halibut exhibit temperature‐dependent sex determination.Rearing at 15°C produced an equal sex ratio, while exposure to higher temperatures (19°C and 23°C) caused masculinization.Expression of sex‐related genes (amh, cyp19a1a, foxl2) can be used to identify phenotypic sex. [ABSTRACT FROM AUTHOR]

Scientific monitoring of pelagic fish stocks in 2004–2005 and 2014–2017 provided information on characteristics of sexual maturation of Atlantic chub mackerel Scomber colias in the coastal waters of the Central-Eastern Atlantic. Based on these results we describe ecological and geographical variability of some biological characteristics of the species. Features of sexual maturation of females and males of the mackerel can be described by a logistic equation obtained in the R programming environment. Fork length, at which 50% of individuals aged 1+ are mature, is 18.4 cm for females and 20.0 cm for males; 100% of individuals are mature at age 3+ with a fork length of 32.3 and 30.8 cm for females and males, respectively. A high proportion of spawning chub mackerel individuals in the Central-Eastern Atlantic have been recorded from February to March and from June to July. Chub mackerel in the coastal waters of this region are similar in life cycle characteristics to the populations of the waters off the Canary Islands and the Madeira Archipelago, but differ from the populations of the waters off mainland Portugal, the Azores, South Africa, and the Bay of Biscay in faster sexual maturation and growth rates. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to determine the reproductive cycle and spawning frequency of the sea cucumber Holothuria tubulosa in the northeastern Aegean Sea. Methods: The study covered a period of 12 months, beginning in October 2018 and concluding in September 2019. During this period, sea cucumber samples were collected monthly. Macroscopic and histological examinations of gonadal tubules were conducted to provide credible information for fishery management and aquaculture. Result: The sex ratio of the sampled population was 1:1.3, with 95 males and 130 females. The drained body weights at 50% maturity were 70.90 g for females and 70.80 g for males. The total length at 50% maturity was estimated at 18.58 cm for females and 18.05 cm for males. Gonad maturation was initiated in March and progressed to spawning stages between July and August. From September to February, the gonads were in postspawning and recovery stages. A strong linear correlation was determined between the gonad index and the seawater temperature in the area. Conclusion: The information provided is expected to improve stock management, enforce fishery regulations, and support controlled breeding programs. These measures aim to preserve the natural populations of Holothuria tubulosa and guarantee the long‐term viability of the species in the wild. Impact statementThe Holothuria tubulosa is the most abundant commercial sea cucumber species found in the Mediterranean Sea, particularly in the Aegean Sea. This species plays an important ecological role in nutrient regeneration and surface sediment mineralization in the benthic zone; however, there is significant catch pressure on natural stocks. This study revealed the reproductive cycle of this Mediterranean Sea cucumber species, offering crucial data for sustainable fisheries and aquaculture. By understanding their breeding patterns, we can better manage wild populations and develop controlled breeding programs, ensuring the long‐term survival of the species and supporting healthy marine ecosystems. [ABSTRACT FROM AUTHOR]

The dioecious plant, Hippophae rhamnoides , is a pioneer species in community succession on the Qinghai-Tibet Plateau (QTP), plays great roles in various ecosystem services. However, the males and females of the species differ both in their morphology and physiology, resulting in a change in the ratio of male to female plants depending on the environment. To further explore the functional traits critical to this sex-based distinctive response in the alpine grassland, we have surveyed the sex ratios, measured their photosynthetic parameters, height, leaf area and biomass allocation. The results showed that (i) The males had higher Pn, light saturation point, apparent quantum efficiency, A max and lower water-use efficiency (WUE), which exhibited higher utilization efficiency or tolerance to strong light, while the females indicated higher utilization efficiency for low light and water. And it showed sex-specific biomass allocation patterns. (ii) H. rhamnoides populations across the successional stages all showed a male-biased sexual allocation, which was closely related to sex-specific WUE, Pn, root biomass/total biomass and root–crown ratio. (iii) The leaf traits of H. rhamnoides changed from higher N area, P area and leaf mass per area in the early and late to lower in the middle, which meant they moved their growth strategy from resource rapid acquisition to conservation as the succession progressed. (iv) The increasing soil total phosphorus mostly contributed to regulating the sex bias of populations and variations of traits during the succession. The results are vital for the management of grassland degradation and restoration due to shrub encroachment on the QTP. [ABSTRACT FROM AUTHOR]

Vasoactive-intestinal peptide (Vip) is a pleiotropic peptide with a wide range of distribution and functions. Zebrafish possess 2 isoforms of Vip (a and b), in which Vipa is most homologous to the mammalian form. In female zebrafish, Vipa can stimulate LH secretion from the pituitary but is not essential for female reproduction, as vipa −/− females display normal reproduction. In contrast, we have found that vipa −/− males are severely subfertile and sex ratio of offspring is female-biased. By analyzing all aspects of male reproduction with wild-type (WT) males, we show that the testes of vipa −/− are underdeveloped and contain ∼70% less spermatids compared to WT counterparts. The sperm of vipa −/− males displayed reduced potency in terms of fertilization (by ∼80%) and motility span and duration (by ∼50%). In addition, vipa −/− male attraction to WT females was largely nonexistent, indicating decreased sexual motivation. We show that vipa mRNA and protein is present in Leydig cells and in developing germ cells in the testis of WT, raising the possibility that endogenous Vipa contributes to testicular function. Absence of Vipa in vipa −/− males resulted in downregulation of 3 key genes in the androgen synthesis chain in the testis, 3β-hsd, 17β-hsd1 , and cyp11c1 (11β-hydrogenase), associated with a pronounced decrease in 11-ketotestosterone production and, in turn, compromised reproductive fitness. Altogether, this study establishes a crucial role for Vipa in the regulation of male reproduction in zebrafish, like in mammals, with the exception that Vipa is also expressed in zebrafish testis. [ABSTRACT FROM AUTHOR]

Context: The quagga catshark (Halaelurus quagga) is a small-sized (~370-mm total length), deep-water catshark (Family: Pentanchidae), assessed as Data Deficient on the IUCN Red List. Aim: We aimed to bridge critical knowledge gaps on aspects of the life history and exploitation of H. quagga to make a meaningful Red List assessment, and develop management plans. Methods: Specimens landed as bycatch in three harbours along the Laccadive Sea coast of south-western India were examined to gather the first information on exploited length classes and aspects of reproductive biology. Key results: Halaelurus quagga had a female-dominated sex ratio, a positively allometric growth in females, and isometric growth in males. Mature H. quagga males ranged between 294 and 336 mm, and females between 315 and 370 mm, with pregnant females carrying two, three or four egg cases with embryos in each uterus. Conclusions: This study provides the first information on the biology and exploitation of H. quagga , showing that the species is landed (and discarded) as bycatch in trawl fisheries, with the catches comprising a significant amount of reproductively active individuals. Implications: The intense deep-sea bottom-trawling off south-western India is a major threat to H. quagga , and, if left unmanaged, could likely trigger a threatened category on the IUCN Red List. The first study on the exploitation levels and aspects of biology of Halaelurus quagga , a poorly known deep-water catshark, showed a female-dominated sex ratio, a positively allometric growth in females and isometric growth in males. Mature H. quagga males ranged between 294 and 336 mm, and females between 315 and 370 mm, with pregnant females carrying two, three or four egg cases, with embryos in each uterus. This species is landed (and discarded) as bycatch in shrimp fisheries, with the catches comprising a significant amount of reproductively active individuals. [ABSTRACT FROM AUTHOR]

Small-scale fisheries have been typically data-limited despite their economic importance for local communities. This is especially true in zones where fishing operations occur in remote areas under harsh weather conditions. Crab fishery in Chile is exclusively artisanal, and marble crab (Metacarcinus edwardsii) has the highest landing records. This species is found in most parts of the coast of Chile, but it is mainly caught in the south of the country (including Patagonia). Fishery management is data-limited, and monitoring has not established the spatial and temporal variability baseline necessary to determine its exploitation status. This fishery is currently evaluated annually under a scheme based on reporting biological and fishery information, primarily from the landing ports and secondarily from fishing grounds. In the present study, we collected data from fishing grounds on board artisanal fishing vessels around 45°S during an annual cycle to establish indicators based on catch per unit effort (above and below minimum legal size), size, sex ratio, and the relationship between weight and size. Our results showed that fishery and biological indicators respond more to seasonal patterns than to expected spatial heterogeneity related to different fishing grounds: proportional stock density (lowest in winter), sex ratio (biased toward males in winter), retained catch (highest in autumn), and released catch (highest in winter), while the average size of the largest 10% of the sample only showed differences between males and females. Additionally, released catch varied according to soak time, which indicates the effectiveness of escape rings incorporated in the traps. These results lead to recommendations related to the current monitoring program, which should include the selection of a limited number of fishing grounds standardized by season and the incorporation of information related to soak time and the presence of escape rings. Finally, this study highlights the importance of on-board scientific monitoring for any fisheries, even those of small scale. [ABSTRACT FROM AUTHOR]

The life‐history tradeoff between reproduction and survival often results in a discordant timing of peak mortality risk for males and females in seasonally reproducing species. Understanding how this seasonal association between reproductive investment and survival is impacted by individual age, demography, and climate is increasingly important as anthropogenic influence is driving rapid global climate and population structure changes. We investigate how tradeoffs between seasonal reproductive investment and survival have fluctuated in response to observed changes in demography and climate using 60 years of demographic records collected from a free‐ranging population of rhesus macaques Macaca mulatta (n = 1919 males, 1609 females). Seasonal mortality rates fluctuated significantly over the 60‐year period for both males and females. In males, but not females, age‐specific survival was different during periods of low and high reproductive investment, indicating that tradeoffs between reproduction and survival are particularly age‐dependent in males. There was no little to no evidence for an effect of sex ratio on survival in either sex. In both sexes, higher population density was associated with lower survival, and this negative effect of density was particularly strong during each sex's period of low reproductive investment. While there was no evidence for an effect of temperature on female survival during periods of low reproductive investment, during periods of high reproductive investment there was a positive association between average daily temperature maximum and female survival. Female survival was higher overall when rainfall was greater, and this positive effect of rainfall on survival was particularly strong for females during periods of low reproductive investment. Conversely, there were no effects of temperature or rainfall on male survival. The results of this study illustrate the considerable ways that climatic and demographic factors can influence sex‐specific mortality during each sex's distinct periods of reproductive investment. [ABSTRACT FROM AUTHOR]

The species of the adaptive male–female sex ratio has different effects on the bio-community. This paper is aimed at figuring out these effects through mechanism analysis and Ordinary Differential Equation (ODE). Hence, the ODE environmental model is created by combining the Lotka–Volterra model, the interspecific model, and other external factors. The stability is used to characterize these effects. According to this model, effects on bio-community stability under different male–female sex ratios are roughly observed. By innovatively considering different living environments during the species' lifecycle, the ODE environmental model is optimized, and the effects of different male–female sex ratios on the bio-community are further analyzed by phase-track maps and relative standard deviation. It is found that there are different findings and features in resource-rich and resource-scarce living environments during the lifecycle. Meanwhile, bio-communities in these two types of environments are in a stable state based on different male–female sex ratios. Based on these findings, directive opinions can be used to manage and help relevant bio-communities. [ABSTRACT FROM AUTHOR]

The evolution of nuptial gifts has traditionally been considered a harmonious affair, providing benefits to both mating partners. There is growing evidence, however, that receiving a nuptial gift can be actively detrimental to the female. In decorated crickets (Gryllodes sigillatus), males produce a gelatinous spermatophylax that enhances sperm transfer but provides little nutritional benefit and hinders female post-copulatory mate choice. Here, we examine the sexually antagonistic coevolution of the spermatophylax and the female feeding response to this gift in G. sigillatus maintained in experimental populations with either a male-biased or female-biased adult sex ratio. After 25 generations, males evolving in male-biased populations produced heavier spermatophylaxes with a more manipulative combination of free amino acids than those evolving in female-biased populations. Moreover, when the spermatophylax originated from the same selection regime, females evolving in male-biased populations always had shorter feeding durations than those evolving in female-biased populations, indicating the evolution of greater resistance. Across populations, female feeding duration increased with the mass and manipulative combination of free amino acids in the spermatophylax, suggesting sexually antagonistic coevolution. Collectively, our work demonstrates a key role for interlocus sexual conflict and sexually antagonistic coevolution in the mating system of G. sigillatus. [ABSTRACT FROM AUTHOR]

Simple Summary: This review reports on the current and potential utility of the "koala scat" sample to provide a range of ecological and physiological assessments both at the population and individual animal level and do so in a non-invasive manner. DNA recovered from the scat sample provides useful information on koala distribution, diet, genetics and disease, whereas hormone metabolites can inform physiology. While there are still limitations with respect to the decay of quality DNA (host, microbiome, and pathogen) over time related to climate and sample handling, some of these issues can be overcome with timely sample collection. Other current limitations include an inability to detect and quantify particular hormone metabolites such as oestrogens and/or an appropriate biological interpretation of glucocorticoid metabolite secretion when measured in the faecal sample. The use of samples or scats to provide important ecological, genetic, disease and physiology details on free-range populations is gaining popularity as an alternative non-invasive methodology. Koala populations in SE Queensland and NSW have recently been listed as endangered and continue to face anthropomorphic and stochastic environmental impacts that could potentially lead to their extinction. This scoping review examines the current and potential utility of the koala scat to contribute data relevant to the assessment of koala conservation status and decision making. Although we demonstrate that there is great potential for this methodology in providing details for both individual wild animal and population biology (distribution, abundance, sex ratio, immigration/emigration, genetic diversity, evolutionary significant unit, disease epidemiology, nutrition, reproductive status and stress physiology), the calibre of this information is likely to be a function of the quality of the scat that is sampled. [ABSTRACT FROM AUTHOR]

Knowledge of species distribution and, for migratory species, seasonal occurrence is particularly important for vulnerable and protected animals such as bats. The former European bat species Pipistrellus pipistrellus was split into two, Pipistrelus pipistrellus s.s. and Pipistrelus pygmaeus, over 20 years ago. However, their distribution, breeding and winter ranges as well as migratory status in Eastern Europe and the Caucasus remained obscure.In our study, we scrutinised records of both species and assessed the sex ratio during their breeding season in this region.We show that Pipistrellus pipistrellus s.s. has a significantly smaller range than previously assumed, being restricted to the southern part of the study area. On the contrary, Pipistrelus pygmaeus has a broader distribution, covering the Caucasus and Eastern Europe, up to ca. 59° N. Hence, all historical records and long‐distance movements of Pipistrellus pipistrellus sensu lato from Eastern Europe within the inferred allopatric occurrence of Pipistrelus pygmaeus should be attributed to Pipistrelus pygmaeus.The high portion of adult males in breeding localities, mass wintering within the breeding range and lacking evidence of long‐distance seasonal movements imply that Pipistrellus pipistrellus s.s. is a sedentary species. In Pipistrelus pygmaeus, the sex ratio among adults during the breeding season varies latitudinally. The female‐biased sex ratio, absence of mass wintering and the historical long‐distance recoveries of ringed individuals suggest that this species is migratory in Eastern Europe. The male‐biased sex ratio during the breeding season, along with late autumn records, suggests that the Caucasus represents its winter range. [ABSTRACT FROM AUTHOR]

The Barda Wildlife Sanctuary (Barda WLS) is a semi-arid ecosystem that plays an important role in the conservation of mammalian carnivores. It is essential to evaluate the population of important wild prey species in Barda, which has conservation implications for mammalian predators and themselves. We assessed the density, biomass, and population structure of wild prey species by surveying road (n = 10) and trail (n = 8) transects using the distance sampling framework method. We used male-to-female sex ratios and the percent contribution of each age class to assess population structure. Mean group size (MGS), median group size (Mdgs), and mean crowding (Mc) were calculated to analyze group size. Of the species studied, Indian peafowl had the highest density (51.61 ± 7.08 individuals/km2), followed by wild pig (10.77 ± 4.59), blue bull (3.50 ± 0.51), Indian hare (3.03 ± 0.73), and spotted deer (0.62 ± 0.04). The male-to-adult female sex ratio was biased towards females, except for Indian peafowl. All species had small group sizes except wild pigs. The results of this study can aid in its development as one of the important protected areas in Gujarat for the conservation of mammalian predators, along with framing conservation strategies for Barda WLS. [ABSTRACT FROM AUTHOR]

The silver pomfret fish Pampus candidus (Previously known as Pampus argenteus Euphrasen) was collected from Iraqi marine waters in the northwest Persian Gulf between April and December 2021, using gillnet and demersal trawling. The lengths and weights of fish were recorded, along with data on the initial maturity length, sex ratio, gonadosomatic index (GSI), Dobriyal index, gonad maturation, development cycle, and absolute fecundity rate. The forked length of female individuals varied from 248 to 281mm, whereas that of male individuals ranged from 124 to 194mm. In July, young fish began to appear. Male individuals had a somehow shorter period of sexual maturity compared to female counterparts. Furthermore, it is noted that males tend to be generally less in size compared to females. The length at first maturity female and male was recorded as 203 and 115mm, respectively. The sex ratio tends to increase for males, and there were two peaks in the rise of the gonadosomatic index and Dobriyal's index, which indicate two periods of spawning activity during June and September. Six stages of fish maturity have been identified, with differences in the size of the eggs. They had a long and continuous breeding season that lasted from May to November, and they spawned by releasing eggs in batches. Notably, they have two distinct reproductive periods: The first during May and June and the second during October and November. The relationship of fecundity with weight was found to be more representative than with length. The document mentions that the silver pomfret spawning and nursery areas are adjacent to the Shatt al-Arab discharge area. [ABSTRACT FROM AUTHOR]

The present study was conducted in the Hammam Debagh reservoir northeastern Algeria from November 2019 to April 2020. To study the age and growth of the Pikeperch (Sander lucioperca) population in this reservoir, 126 specimens were sampled, including 77 males and 49 females. The ages, total lengths, and total weights of the samples ranged from 0- 7 years, 15.7- 57.1cm and 92.1 to 1883g, respectively. The age of the fish was determined by the direct method (scalimetry). The lenght-weight relationship was described by the equation TW = 0.003TL3.28 for total weight and EW = 0.002TL3.43 for eviscerated weight. The ANCOVA test showed no significant difference between the sexes’ slopes of the length-weight relations (F = 3.445, P> 0.05). The von Bertalanffy growth parameters deduced by introducing the average age/length couples were L∞ = 61.86cm; K= 0.30 year-1, and t0 = -0.52. The equation of the linear growth curve according to the von Bertalanffy model was written as Lt = 61.86 (1-e - 0.3(t+0.52) ), and the equation of the weight growth curve was written as Wt = 2253.96 (1-e -0.3(t+0.52)) 3.28 . The studied species showed a higher rate of masculinity (61.11%) than of femininity (38.89%). The overall sex ratio was in favor of males (SR = 1.57, χ² = 6.22; P< 0.05), except in March when males dominated (SR = 3: 1 ; χ² = 6.00 ; P< 0.05). The monthly variation of the sex ratio was constant throughout the study. The evolution of the sex ration according to the size of the fish showed no significant difference between males and females (0.806 ≤ χ² ≤ 2.123 ; P˃ 0.05). [ABSTRACT FROM AUTHOR]

Melanin-based color polymorphism is predicted to evolve and maintain through differential fitness of morphs in different environments, and several empirical studies indicate that life history strategies, physiology, and behavior vary among color morphs. Sex allocation theory predicts that parents should adjust their sex allocation based on differential costs of raising sons and daughters, and therefore, color morphs are expected to modify their brood sex ratio decisions. In color polymorphic tawny owls (Strix aluco), the pheomelanistic brown morph is associated with higher energy requirements, faster growth, and higher parental effort than the gray morph. As hypothesized, we find that brown tawny owl mothers produced more daughters in early broods and more males in late broods, whereas gray mothers did the opposite. At fledging, daughters of early broods and of brown mothers were heavier than those of late broods or gray mothers. Hence, larger and more costly daughters appeared to benefit more than males from being born to brown mothers early in the season. Brown mothers breeding later in the season produced more cheap sons, while gray mothers face fewer challenges under limited resources and favor daughters. These findings suggest that environmental conditions influence brood sex allocation strategies of genetically determined color morphs differently. [ABSTRACT FROM AUTHOR]

Crassostrea (Magallana) saidii has been commercially ranched in Malaysia and consumed for more than 160 years, but it was only recently identified as a new species to science. This study was conducted to evaluate the reproductive phenology of C. (M.) saidii. Samples of 30 individual oysters were taken monthly for 15 months from the sole population at Sungai Muar estuary in Johor, Malaysia. The sex ratio was 1:1.64 (male:female) for all examined specimens, with female numbers significantly higher. Hermaphrodism was detected in 1.56% of all samples. Spawning peaks in April (2019) and November (2018 and 2019), and were positively associated with the increased rainfall upstream. Gametogenesis occurred throughout the research period with temporal variations. The highest values of maturity index (MI) were recorded in March, August and October 2019, when most oysters were in matured and maturing stages. Condition index (CI) ranged from 31.90 ± 1.25 (April 2019) to 70.03 ± 3.23 (October 2019), exhibiting two peaks (March and October 2019) and subsequently reduced in CI indicating spawning consistency with histological observations. Anthropogenic stressors such as heavy sedimentation and inland development are threatening the survival of this species. The understanding of their reproductive biology is essential to ensure the survival and sustainability of C. (M.) saidii fishery. [ABSTRACT FROM AUTHOR]

Spawning performance -relative fecundity and fertilization success-was studied in two hatchery-reared broodstocks of gilthead seabream (Sparus aurata) held under relatively constant well-water temperature (18-20 °C) and simulated natural photoperiod, for five consecutive spawning seasons, between 3 and 7 years of age. The spawning season lasted between 4 and 6 months each year, and the total number of eggs produced annually ranged between 1 480 000 and 3 100 000 eggs/kg female body weight, being the highest during the first and second spawning season. No difference was observed in monthly relative fecundity between years -although high variation existed within years, whereas fertilization success was the highest during the second and third reproductive season, and dropped significantly during the last year of the study. The male percentage of the broodstocks was 35% during the first spawning season of the females, and thereafter it decreased further and remained stable at around 15%-20% for the second and third spawning season. Substitution of older females with smaller males to readjust male percentage to 50% in the fourth spawning season, was followed by sex change of larger males to females and a drop of the male percentage to 18% in the following spawning season. The present study demonstrated the long spawning season of gilthead seabream -especially under constant water temperature, the high fecundity and fertilization success, and the stabilization of male percentage to ~20% after the first spawning season or when a broodstock is modified to increase male percentage. These results are useful to the aquaculture industry, demonstrating that there is no need to add males to gilthead seabream broodstocks over the years, as the sex ratio is stabilized and egg production and fertilization success remain high with a relatively low male:female sex ratio. [ABSTRACT FROM AUTHOR]

The "paradox of sex" refers to the question of why sexual reproduction is maintained in the wild, despite how costly it is compared to asexual reproduction. Because of these costs, one might expect nature to select for asexual reproduction, yet sex seems to be continually selected for. Multiple hypotheses have been proposed to explain this incongruence, including the niche differentiation hypothesis, the Red Queen hypothesis, and accumulation of harmful mutations in asexual species due to inefficient purifying selection. This study focuses on the accumulation of mutations in two terrestrial isopods, Trichoniscus pusillus, which has sexual diploid and parthenogenic triploid forms, and Hyloniscus riparius, an obligately sexual relative. We surveyed sex ratios of both species in an upstate New York population and obtained RNA-seq data from wild-caught individuals of both species to examine within- and between-species patterns of molecular evolution in protein-coding genes. The sex ratio and RNA-seq data together provide strong evidence that this T. pusillus population is entirely asexual and triploid, while the H. riparius population is sexual and diploid. Although all the wild T. pusillus individuals used for sequencing shared identical genotypes at nearly all SNPs, supporting a clonal origin, heterozygosity and SNP density were much higher in T. pusillus than in the sexually reproducing H. riparius. This observation suggests this parthenogenic lineage may have arisen via mating between two divergent diploid lineages. Between-species sequence comparisons showed no evidence of ineffective purifying selection in the asexual T. pusillus lineage, as measured by the ratio of nonsynonymous to synonymous substitutions (dN/dS ratios). Likewise, there was no difference between T. pusillus and H. riparius in the ratios of nonsynonymous to synonymous SNPs overall (pN/pS). However, pN/pS ratios in T. pusillus were significantly higher when considering only SNPs that may have arisen via recent mutation after the transition to parthenogenesis. Thus, these recent SNPs are consistent with the hypothesis that purifying selection is less effective against new mutations in asexual lineages, but only over long time scales. This system provides a useful model for future studies on the evolutionary tradeoffs between sexual and asexual reproduction in nature. [ABSTRACT FROM AUTHOR]

In polygynous species, male reproductive success is often determined by their ability to dominate female harems. Harem‐holders sire a disproportionate number of offspring. Male dominance tends to correlate with age, but intense competition and early male mortality limit most males from achieving high social status. To maximize reproductive success despite low rank, offspring sex ratio adjustment may have evolved, favoring the sex with higher fitness. If traits influencing dominance are heritable and confer reproductive advantages, we expect fathers with higher reproductive success to produce more sons, as they are more likely to become dominant. In contrast, subordinate males with lower success may benefit from siring more daughters. We tested this hypothesis on a colony of southern elephant seals breeding on the Kerguelen Archipelago. We used genetic markers to link the paternity of 540 pups to 58 breeding males. We found that the probability of siring a son increases from 43% to 54% with paternal relative reproductive success, supporting the offspring sex ratio adjustment hypothesis. Given that various factors influence sex ratio in a population, future studies should tease apart these ecological processes (e.g., paternal dominance, maternal condition, local density, or adult sex ratio) and investigate how they interact with each other. [ABSTRACT FROM AUTHOR]

The potential effect of a demographic transition on industrialization is of interest to scholars in both demography and economics. This study contributes to the literature by providing empirical evidence that a demographic transition creates population pressure that can facilitate rural industrialization. By studying China's rapid demographic transition in the late twentieth century before massive internal labor migration took off and linking it to large regional variations in the process of rural industrialization in the wake of the country's market-oriented reforms, we find that initial local population pressure is positively associated with subsequent rural industrial development, proxied by the extensive growth in local privately and collectively owned enterprises. Population pressure was more significantly associated with rural industrialization than other demographic factors considered, such as birthrate, dependency ratio, and sex ratio at younger ages. [ABSTRACT FROM AUTHOR]

Date palm borers are among the most important pests of date trees in Iran. This study aimed to determine the population fluctuations of rhinoceros beetles Oryctes sp., infesting the date palm Phoenix doctylifera, using light traps in Mahshar date palm orchards. Samplings were weekly conducted from 2021 to 2022 in two randomly selected date palm orchard. Over two years of monitoring coleopteran adults, two species of the genus Oryctes namely O. agamemnon mathiesseni and O. elegans were observed. The beginning seasonal activity of both univoltine species was middle May, reaching the peaks during summer, and the populations declined gradually till October. In each of research years, one of two species was dominant, so that in the first year, the number of adult beetles of O. agamemnon mathiesseni was significantly more than O. elegans, while in the second year, the number of O. elegans was higher. In both sampling years, the activity of dominant species in that year started earlier, and ended later. A two-year study of the sex ratio in these horned beetles revealed that females outnumbered males substantially (2.5 to 4 times in two years) in the subspecies O. agamemnon mathiesseni. For O. elegans, this ratio ranged from 1.5 times (2021) to 2.5 times (2022). The successful IPM programs are effectively dependent on prediction of the emergence time and population fluctuations of pest insects, and it is hoped that the results of this study will be useful to control of the rhinoceros beetles. [ABSTRACT FROM AUTHOR]

Antagonistic selection has long been considered a major driver of the formation and expansion of sex chromosomes. For example, sexually antagonistic variation on an autosome can select for suppressed recombination between that autosome and the sex chromosome, leading to a neo-sex chromosome. Autosomal supergenes, chromosomal regions containing tightly linked variants affecting the same complex trait, share similarities with sex chromosomes, raising the possibility that sex chromosome evolution models can explain the evolution of genome structure and recombination in other contexts. We tested this premise in a Formica ant species, wherein we identified four supergene haplotypes on chromosome 3 underlying colony social organization and sex ratio. We discovered a novel rearranged supergene variant (9r) on chromosome 9 underlying queen miniaturization. The 9r is in strong linkage disequilibrium with one chromosome 3 haplotype (P2) found in multi-queen (polygyne) colonies. We suggest that queen miniaturization is strongly disfavored in the single-queen (monogyne) background and is thus socially antagonistic. As such, divergent selection experienced by ants living in alternative social "environments" (monogyne and polygyne) may have contributed to the emergence of a genetic polymorphism on chromosome 9 and associated queen-size dimorphism. Consequently, an ancestral polygyne-associated haplotype may have expanded to include the polymorphism on chromosome 9, resulting in a larger region of suppressed recombination spanning two chromosomes. This process is analogous to the formation of neo-sex chromosomes and consistent with models of expanding regions of suppressed recombination. We propose that miniaturized queens, 16%-20% smaller than queens without 9r, could be incipient intraspecific social parasites.

Social behaviours are typically modelled using neighbour-modulated fitness, which focuses on individuals having their fitness altered by neighbours. However, these models are either interpreted using inclusive fitness, which focuses on individuals altering the fitness of neighbours, or not interpreted at all. This disconnect leads to interpretational mistakes and obscures the adaptive significance of behaviour. We bridge this gap by presenting a systematic methodology for constructing inclusive-fitness models. We find a behaviours inclusive-fitness effect by summing primary and secondary deviations in reproductive value. Primary deviations are the immediate result of a social interaction; for example, the cost and benefit of an altruistic act. Secondary deviations are compensatory effects that arise because the total reproductive value of the population is fixed; for example, the increased competition that follows an altruistic act. Compared to neighbour-modulated fitness methodologies, our approach is often simpler and reveals the models inclusive-fitness narrative clearly. We implement our methodology first in a homogeneous population, with supplementary examples of help under synergy, help in a viscous population and Creels paradox. We then implement our methodology in a class-structured population, where the advantages of our approach are most evident, with supplementary examples of altruism between age classes, and sex-ratio evolution.