Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
303
datasets available to search
ShareScore release 0.7.1
Dataset results
303 results for “sex ratio”
Data from: Potential drivers and implications of a balanced breeding sex ratio in a small population of an imperiled species with environmental sex determination
Open the record for dataset details and reuse information.
Data from: Female-biased population sex ratios caused by genetic rather than ecological mechanisms in dwarf willow (Salix herbacea L.)
Open the record for dataset details and reuse information.
Data belonging to the article: Estimating pre-harvest density, adult sex ratio and fecundity of white-tailed deer using wildlife cameras
Open the record for dataset details and reuse information.
Experimental evolution under varying sex ratio and behavioral plasticity in response to perceived competitive environment independently affect calling effort in male crickets
Open the record for dataset details and reuse information.
Split sex ratio due to maternal condition
Open the record for dataset details and reuse information.
In search of the genetic variants of human sex ratio at birth: Was Fisher wrong about sex ratio evolution?
Open the record for dataset details and reuse information.
Adult sex-ratio bias does not lead to detectable adaptive offspring sex allocation via nest-site choice in a turtle with temperature-dependent sex determination
Open the record for dataset details and reuse information.
Range-wide study in a sexually polymorphic wild strawberry reveals climatic and soil associations of sex ratio, sexual dimorphism, and sex chromosomes
Open the record for dataset details and reuse information.
The Combined Effects of Road Salt and Biotic Stressors on Amphibian Sex Ratios
Aquatic systems worldwide are threatened by the anthropogenic use of synthetic chemicals, including pesticides, pharmaceuticals, and road de‐icers. Exposure to contaminants can alter the behavior, morphology, and physiology of organisms if it occurs during sensitive life stages. For instance, past studies have documented feminization of male amphibians following herbicide exposure and skewed sex ratios among amphibian populations exposed to road salt. However, many of these studies lack the complexities found within natural environments, such as competition with conspecifics or threat of predation, which are also known to influence development. Thus, it is important to understand how anthropogenic and natural stressors interact to alter animal sex ratios. Given the growing concern of secondary salinization of freshwater systems, we exposed larval wood frogs (Rana sylvatica) to either road salt (sodium chloride [NaCl]) or an alternative salt mixture (NaCl, magnesium chloride [MgCl2], and potassium chloride [KCl]) at 3 concentrations (200, 600, and 1000 mg Cl−/L) crossed with 3 biotic stressors (no‐stressor control, competition, or predator cues) to examine their potentially interactive effects on sex. Exposure to biotic stressors and NaCl did not influence wood frog sex ratios. In contrast, tadpole exposure to the intermediate salt mixture concentration significantly reduced the proportion of female frogs. Future studies are needed to determine whether such changes in sex are widespread among sensitive species with complex life cycles, and to assess the consequences of sex ratio changes on long‐term population dynamics.
Data from: A seasonal shift in offspring sex ratio of the brood parasitic Brown-headed Cowbird (Molothrus ater)
<p>Avian obligate brood parasites do not provide parental care for their eggs and young, and may therefore serve as a strong model system to test predictions of evolutionary sex-allocation theories, independent of parental modulation of primary sex ratios. However, none of the handful of previous studies examining offspring sex ratio in brood parasitic birds have revealed a bias from parity at the level of the female parasite, the host species, or temporal scale(s). This is also surprising, because in at least one brood parasite, the Brown-headed Cowbird (Molothrus ater), adult sex ratios are consistently and heavily male-biased. Here we used a large database of embryonic and nestling cowbirds' genetic sex ratios collected from nests of a single host species, the Prothonotary Warbler (Protonotaria citrea) to assess potential overall, temporal, and individual patterns of bias. Contrary to previous findings, we documented an increase in the calculated male sex ratios later in the breeding season. There was no effect of whether embryos or nestlings were sampled, implying a lack of host parental effect on shifting the primary-to-secondary sex ratios of brood parasitic offspring. Future work should explore the sex-specific survival and recruitment pattern of fledgling cowbirds raised by this and other host species to reconcile theoretical and empirical predictions and patterns.</p>
Data from: Detecting the population dynamics of an autosomal sex-ratio distorter transgene in malaria vector mosquitoes
<p>1. The development of genetically modified mosquitoes and their subsequent field release offers innovative and cost-effective approaches to reduce mosquito-borne diseases, such as malaria. A sex-distorting autosomal transgene has been developed recently in G3 mosquitoes, a lab strain of the malaria vector Anopheles gambiae s.l. The transgene expresses an endonuclease called I-PpoI during spermatogenesis, which selectively cleaves the X chromosome to result in ~95% male progeny. Following the World Health Organization Guidance Framework for the testing of genetically modified mosquitoes, we assessed the dynamics of this transgene in large cages using a joint experimental-modelling approach.</p> <p>2. We performed a four-month experiment in indoor large cages to study the population genetics of the transgene. The cages were set up to mimic a simple tropical environment with a diurnal light-cycle, constant temperature, and constant humidity. We allowed the generations to overlap to engender a stable age structure in the populations. We constructed a model to mimic the experiments, and used the experimental data to infer the key model parameters.</p> <p>3. We identified two fitness costs associated to the transgene. First, transgenic adult males have reduced fertility and, second, their female progeny have reduced pupal survival rates. Our results demonstrate that the transgene is likely to disappear in less than three years under our confined conditions. Model predictions suggest this will be true over a wide range of background population sizes and transgene introduction rates.</p> <p>4. Synthesis and applications: Our semi-field indoor cage experiments are in line with WHO guidance recommendations in regards to the development and testing of self-limiting technologies. Since the transgenic strain (Ag(PMB)1) has been considered for genetic vector control of malaria, our results are fundamentally important for determining expectations on the persistence of the transgene post-release. Our results provide a demonstration of the self-limiting nature of the transgene, and indicate that longevity will be further reduced by fitness costs that were not previously identified. Finally, our study has showcased an alternative and effective method for characterising the phenotypic expression of a transgene in an insect pest population.</p>
Sex-specific patterns of senescence in artificial insect populations varying in sex-ratio to manipulate reproductive effort
<p><strong>Background:</strong> The disposable soma theory of ageing assumes that organisms optimally trade-off limited resources between reproduction and longevity to maximize fitness. Early reproduction should especially trade-off against late reproduction and longevity because of reduced investment into somatic protection, including immunity. Moreover, as optimal reproductive strategies of males and females differ, sexually dimorphic patterns of senescence may evolve. In particular, as males gain fitness through mating success, sexual competition should be a major factor accelerating male senescence. In a single experiment, we examined these possibilities by establishing artificial populations of the mealworm beetle, <em>Tenebrio molitor</em>, in which we manipulated the sex-ratio to generate variable levels of investment into reproductive effort and sexual competition in males and females.</p> <p><strong>Results:</strong> As predicted, variation in sex-ratio affected male and female reproductive efforts, with contrasted sex-specific trade-offs between lifetime reproduction, survival and immunity. High effort of reproduction accelerated mortality in females, without affecting immunity, but high early reproductive success was observed only in balanced sex-ratio condition. Male reproduction was costly on longevity and immunity, mainly because of their investment into copulations rather than in sexual competition.</p> <p><strong>Conclusions:</strong> Our results suggest that <em>T. molitor</em> males, like females, maximize fitness through enhanced longevity, partly explaining their comparable longevity. </p>
Data from: Deer indirectly alter the reproductive strategy and operational sex ratio of an unpalatable forest perennial
Environmental conditions impose restrictions and costs on reproduction. Multiple reproductive options exist when increased reproductive costs drive plant populations toward alternative reproductive strategies. Using four years of demographic data across a deer impact gradient, where deer alter the abiotic environment, we parameterize a size-dependent integral projection model for a sexually labile and unpalatable forest perennial to investigate the demographic processes driving differentiation in the operational sex ratio (OSR) of local populations. In addition to a relative increase in asexual reproduction, our results illustrate that non-trophic indirect effects by overabundant deer on this perennial result in delayed female sex expression to unsustainably large plant sizes and leads to more pronounced plant shrinkage following female sex expression, effectively increasing the cost of reproduction. Among plants of reproductive age, increased deer impact decreases the size-dependent probability of flowering and reduces reproductive consistency over time. This pattern in sex expression skews populations toward female-biased OSRs at low deer impact sites and male-biased OSRs at intermediate and high deer impact sites. While this shift toward a male-biased OSR may ameliorate pollen limitation, it also decreases the effective population size when coupled with increased asexual reproduction. The divergence of reproductive strategies and reduced lifetime fitness in response to indirect deer impacts illustrate the persistent long-term effects of overabundant herbivores on unpalatable understory perennials.
Does operational sex ratio influence relative strength of purging selection in males vs. females?
<p>According to theory, sexual selection in males may efficiently purge mutation load of sexual populations, reducing or fully compensating "the cost of males". For this to occur, mutations not only need to be deleterious to both sexes, they also must affect males more than females. A frequently overlooked problem is that relative strength of selection on males vs. females may vary between environments, with social conditions being particularly likely to affect selection in males and females differently. Here we induced mutations in red flour beetles (Tribolium castaneum) and tested their effect in both sexes under three different operational sex ratios (1:2, 1:1, 2:1). Induced mutations decreased fitness of both males and females, but their effect was not stronger in males. Surprisingly, operational sex ratio did not affect selection against deleterious mutations nor its relative strength in the sexes. Thus, our results show no support for the role of sexual selection in the evolutionary maintenance of sex.</p> <p> </p>
Data from: Climate warming and sea turtle sex ratios across the globe
<p><span>Climate warming and the feminisation of populations due to temperature-dependent sex determination may threaten sea turtles with extinction. To identify sites of heightened risk, we examined sex ratio data and patterns of climate change over multiple decades for 64 nesting sites spread across the globe. Over the last 62 years the mean change in air temperature was 0.85 °C per century (SD = 0.65 °C, range = -0.53 to +2.5 °C, n = 64 nesting sites). Temperatures increased at 40 of the 64 study sites. Female-skewed hatchling or juvenile sex ratios occurred at 57 of the 64 sites, with skews > 90% female at 17 sites. We did not uncover a relationship between the extent of warming and sex ratio (r62 = -0.03, p = 0.802, n = 64 nesting sites). Hence, our results suggest that female-hatchling sex ratio skews are not simply a consequence of recent warming but have likely persisted at some sites for many decades. So other factors aside from recent warming must drive these variations in sex ratios across nesting sites, such as variations in nesting behaviour (e.g., nest depth), substrate (e.g., sand albedo), shading available and rainfall patterns. While overall across sites recent warming is not linked to hatchling sex ratio, at some sites there is both is a high female skew and high warming, such as Raine Island (Australia; 99% female green turtles; 1.27 °C warming per century), nesting beaches in Cyprus (97.1% female green turtles; 1.68 °C warming per century), and in the Dutch Caribbean (St Eustatius; 91.5% female leatherback turtles; 1.15 °C warming per century). These may be among the first sites where management intervention is needed to increase male production. Continued monitoring of sand temperatures and sex ratios are recommended to help identify when high incubation temperatures threaten population viability.</span></p>
Italian Nuts2 Sex Ratio - Workshop Biodemography - Example
<p>This is a sample dataset for the Biodemography Workshop. Within this dataset, input files related to demographic statistics will be considered, specifically population by gender and by Nuts2 in Italy, as well as shapefiles for map creation. The variables to be analyzed include the ratio between male and female, and vice versa. The final output consists of two maps. The data source is Istat, which provides these with a CC BY license:</p><p>1-<a href="https://demo.istat.it/app/?i=POS&l=it">https://demo.istat.it/app/?i=POS&l=it</a></p><p>2-<a href="https://www.istat.it/it/archivio/222527">https://www.istat.it/it/archivio/222527</a></p><p>To conduct the analysis, the open-source software R-Studio was used. The data management methodology will also be outlined in a Data Management Plan, written using Overleaf, in which we will provide more detailed information.</p>
Data from: The effect of operational sex ratio and density on the strength of sexual selection against mutant males in Drosophila melanogaster
<p>Higher male:female operational sex ratio (OSR) is often assumed to lead to stronger sexual selection on males. Yet, this premise has been directly tested by very few studies, with mixed outcomes. We investigated how OSR affects the strength of sexual selection against two deleterious alleles, a natural <em>ebony</em> mutant and a transgenic <em>GFP</em> insertion, in <em>Drosophila melanogaster. </em>To this end, we estimated the relative paternity share of homozygous mutant males competing against wildtype males under different OSRs (1:2, 1:1, 2:1). We also manipulated the mating pool density (18, 36 or 54 individuals), and assessed paternity over three consecutive days, during which the nature of sexual interaction changed. The strength of sexual selection against the <em>ebony</em> mutant increased with OSR, became weaker after the first day and was little affected by density. In contrast, sexual selection against the <em>GFP</em> transgene was markedly affected by density: at the highest density it increased with OSR, but at lower densities it was strongest at 1:1 OSR, remaining strong throughout the experiment. Thus, while OSR can strongly affect the strength of sexual selection against "bad genes", it does not necessarily increase monotonically with male:female OSR. Furthermore, the pattern of relationship between OSR and the strength of sexual selection can be locus-specific, likely reflecting the specific phenotypic effects of the mutation.</p>
Boreal Owl Offspring Sex Ratio
<p>The dataset is associated with the paper titled “<strong>Fledgling Sex Ratio Is Determined by Egg Loss, Hatching Order, Nestling Mortality, and Inter‐Annual Food Fluctuations for Boreal Owls, </strong><em>Aegolius funereus</em>”, published in <em>Ecology and Evolution</em> (2025). The XLS file contains three sheets, each corresponding to one of the models described in the paper, along with an additional sheet providing information about the data.</p>
Long-term resilience of primary sex ratios in a species with temperature dependent sex determination after decades of climate warming
<p><span>Species with environmental sex determination (ESD) have persisted through deep time, despite massive environmental perturbation in the geological record. Understanding how species with temperature-dependent sex determination (TSD), a type of ESD, persist through climate change is particularly timely given the current climate crisis, as highly biased sex ratios and extinction are predicted. Since 1982, we have studied primary sex ratios of a reptile with TSD (<em>Chelydra serpentina</em></span><span>). Primary sex ratios remained unchanged over time, despite warming in the environment. Resilience of the primary sex ratio occurred via a portfolio effect, realized through remarkable intra-annual variation in nest-level sex ratios, leading to a relatively consistent mean annual sex ratio. Intra-annual variation in nest-level sex ratios was related to variation in egg burial depth coupled with large clutch sizes, creating thermal gradients in the nest, and promoting mixed-sex clutches. Further, both locally and globally, sustained increases in nighttime air temperature contribute more to warming than increases in daily maximum temperature, but development rate was affected more strongly by maximum daily air temperature, conferring additional resilience to overall warming. Our study suggests that some TSD species may be resilient to warming and provides an example of how ESD may persist under environmental change.</span><span><br></span></p>
Environmental variation in sex ratios and sexual dimorphism in three wind-pollinated dioecious plant species
<p>Variation in plant sex ratios is often attributable to sex-specific mortality in heterogeneous environments that differentially limit male and female plant reproduction. Yet sexual dimorphism and plastic responses to environmental heterogeneity are common and may co-vary with variation in sex ratios. Here, we show that the sex ratio and the degree of sexual dimorphism for a number of plant traits varied along climatic and elevation gradients in three wind-pollinated dioecious species, <em>Rumex lunaria</em>, <em>Urtica dioica</em> and <em>Salix helvetica</em>. Some of the observed sex-specific responses to climatic variation are consistent with greater sensitivity of females to water scarcity, but most responses rather point to the greater sensitivity of males to ecological stress, consistent with larger male reproductive effort, as has been commonly reported for wind-pollinated plants. In contrast, we found no evidence for variation in either sex ratios or sexual dimorphism expected under sexual selection. Interestingly, sex ratios and sexual dimorphism varied both along distinct and the same ecological axes of variation, suggesting that the evolution of sexual dimorphism in the measured traits was not sufficient to prevent sex-specific mortality.</p>
ScienceDex guides
Understand access before you commit
These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.