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.
72
datasets available to search
ShareScore release 0.9.0
Dataset results
72 results for “individual heterogeneity”
Data for: Effects of nutrient heterogeneity on root foraging and plant growth at the individual and community level
<p>Plants can respond to heterogeneous nutrient distribution through selective root placement to enhance nutrient uptake. It is believed that nutrient heterogeneity can better promote plant growth than homogeneous nutrient distribution, but comprehensive analyses are relatively few. We meta-analyzed the data from 131 comparative studies and synthesized the effects of nutrient heterogeneity on root foraging and plant growth, and examined the roles of patch scale and contrast. Plant responses to nutrient heterogeneity was phylogenetically conserved, and the response in shoot biomass was more correlated with the response in root biomass than with root foraging precision. Root precision depended on competition status, and plants in interspecific competition had lower precision. Community-level responses to nutrient heterogeneity were more significant than individual-level responses. With increasing patch scale, root foraging precision declined, while overall shoot and root responses of individuals increased. Moderate patch contrast significantly increased root responses compared to low and high patch contrast. Our results indicate that plants optimize nutrient acquisition from heterogeneous patches mainly through increasing root growth rate and exploit nutrients more effectively at the community than individual level. Patch attribute mediation of nutrient heterogeneity effects on plants may help design fertilization practices to promote productivity and conserve biodiversity. </p>
Mechanisms of individual variation in large herbivore diets: Roles of spatial heterogeneity and state-dependent foraging
<p>Many populations of consumers consist of relatively specialized individuals that eat only a subset of the foods consumed by the population at large. Although the ecological significance of individual specialization is recognized, it is difficult to document and its underlying mechanisms are poorly understood. Optimal foraging theory provides a useful framework for predicting how individuals might select different diets, positing that animals balance the 'opportunity cost' of stopping to eat an available food item against the cost of searching for something more nutritious; diet composition should be contingent on the distribution of food, and foragers should be more specialized when individuals have high energy reserves to spend searching for high-quality foods. We tested these predicted mechanisms of individual niche differences by quantifying environmental (resource heterogeneity) and organismal (nutritional condition) determinants of diet in a widespread browsing antelope (bushbuck, <em>Tragelaphus sylvaticus</em>) in an African floodplain-savanna ecosystem. We quantified individual diet breadth and composition using DNA metabarcoding of fecal samples collected repeatedly from 15 GPS-collared animals (6–14 samples per individual, median 12). Bushbuck diets were structured by spatial heterogeneity and constrained by individual conditions. We observed significant individual-level partitioning of food plants by bushbuck both within and between two adjacent habitat types (floodplain and woodland). Individuals with home ranges that were closer together and/or had similar vegetation structures (measured using LiDAR) ate more similar diets, supporting the prediction that heterogeneous resource distribution promotes individual differentiation. Individuals in good nutritional condition had significantly narrower diets (fewer plant taxa), searched their home ranges more intensively (intensity-of-use index), and had higher-quality diets (percent digestible protein) than those in poor condition, supporting the prediction that animals with greater endogenous reserves are more specialized because they can invest time in searching for nutritious foods. Our results support predictions from optimal foraging theory about the energetic basis of individual specialization and provide a potentially generalizable framework for understanding how individual niche width is governed by animal behavior and physiology in heterogeneous landscapes.</p>
Data from: Successful by chance? the power of mixed models and neutral simulations for the detection of individual fixed heterogeneity in fitness components
Open the record for dataset details and reuse information.
Data for: Effects of nutrient heterogeneity on root foraging and plant growth at the individual and community level
Open the record for dataset details and reuse information.
Data from: Spatial heterogeneity in genetic relatedness among house sparrows along an urban-rural gradient as revealed by individual-based analysis
Open the record for dataset details and reuse information.
Data from: Individual variation in male reproductive behaviour is linked to temporal heterogeneity in predation risk
Open the record for dataset details and reuse information.
Data from: Early-life conditions determine the between-individual heterogeneity in plasticity of calving date in reindeer
Open the record for dataset details and reuse information.
Data from: Extreme climate events and individual heterogeneity shape life-history traits and population dynamics
Open the record for dataset details and reuse information.
Data from: Heterogeneity in individual quality in birds: overall patterns and insights from a study on common terns
Open the record for dataset details and reuse information.
Data from: Parental behavior exhibits among-individual variance, plasticity and heterogeneous residual variance
Open the record for dataset details and reuse information.
Mechanisms of individual variation in large herbivore diets: Roles of spatial heterogeneity and state-dependent foraging
Open the record for dataset details and reuse information.
Data from: Among-individual heterogeneity in maternal behaviour and physiology affects reproductive allocation and offspring life-history traits in the garter snake Thamnophis elegans
Open the record for dataset details and reuse information.
Data from: Estimating latent individual demographic heterogeneity using structural equation models
Open the record for dataset details and reuse information.
Heterogeneity in resource competition covaries with individual variation in long-term social relationships
Open the record for dataset details and reuse information.
Data from: Individual heterogeneity determines sex differences in mortality in a monogamous bird with reversed sexual dimorphism
Open the record for dataset details and reuse information.
Data from: Sex-specific heterogeneity in fixed morphological traits influences individual fitness in a monogamous bird population
Theoretical work has emphasized the important role of individual traits on population dynamics, but empirical models are often based on average or stage-dependent demographic rates. In this study on a monogamous bird, the Eurasian hoopoe (Upupa epops), we show how the interactions between male and female fixed and dynamic heterogeneity influence demographic rates and population dynamics. We built an integral projection model including individual sex, age, condition (reflecting dynamic heterogeneity) and fixed morphology (reflecting fixed heterogeneity). Fixed morphology was derived from a principal component analysis of six morphological traits. Our results revealed that reproductive success and survival were linked to fixed heterogeneity whereas dynamic heterogeneity influenced mainly the timing of reproduction. Fixed heterogeneity had major consequences for the population growth rate, but interestingly, its effect on population dynamics differed between the sexes. Female fixed morphology was directly linked to annual reproductive success whereas male fixed morphology influenced also annual survival, being twice higher in large than in small males. Even in a monogamous bird with shared parental care, large males can reach 10\% higher fitness than females. Including the dynamics of male and female individual traits in population models refines our understanding of the individual mechanisms that influence demographic rates and population dynamics and can help identifying differences in sex-specific strategies.
Data from: The importance of individual heterogeneity for interpreting faecal glucocorticoid metabolite levels in wildlife studies
1. Being a non-invasive and inexpensive method, the analysis of faecal corticosteroid metabolites (FCM) is increasingly being applied in wildlife research. Various environmental factors have been shown to influence FCM levels, but most studies did not account for inter-individual variance, which we hypothesized may substantially affect the results. 2. We combined FCM analysis with genetic analysis to identify the sex and individual of samples collected in three consecutive winters, with repeated samples per individual, across the entire range of an endangered population of capercaillie (Tetrao urogallus) in Southwestern Germany. Using generalized additive mixed models, we modelled FCM levels as a function of sex, season and environmental covariates at two spatial scales (sampling location and home range scales). We compared two models: one including information on the individual animal, and the other excluding this information (i.e. naïve model) to assess the influence of individual effects on the results obtained. 3. Most of the variance (44.0% and 45.1% at the sampling and home range scale, respectively) was explained by the inter-individual differences, and only very little (4.0% and 5.1%, respectively) by the environmental predictors. When ignoring individual effects, the model results changed considerably, with other, previously non-informative predictors, becoming significant. 4. In the full models, accounting for inter-individual variance, no effect was found of weather conditions, at either scale. FCM levels were negatively correlated with habitat quality, at the sampling location, whereas human recreation at the home range scale led to elevated FCM levels. In the naïve models, two additional predictors appeared significant: one weather variable at local scales and two at home range scale. In all models, seasonal FCM patterns differed significantly between males and females. 5. Synthesis and applications. Our results highlight the importance of considering the effects of individual heterogeneity when studying FCM in wildlife research, as ignoring information on the individual might lead to erroneous conclusions. Combining FCM analyses with genetic analyses can be an efficient approach to adequately address this issue.21-Feb-2018
Data from: Heterogeneity in individual quality and reproductive trade-offs within species
Interspecifically, a reasonable body of evidence supports a trade-off between offspring size and number. However, at the intraspecific level, a whole manner of phenotypic correlations between offspring size and number are observed. These correlations may be predicted when heterogeneity in resource availability, or quality, is considered. Making the assumption that maternal size is a proxy for resource availability, we meta-analytically quantified four phenotypic reproductive correlations within numerous species: (1) maternal size and offspring size, (2) maternal size and offspring number, (3) offspring number and offspring size, and (4) offspring number and offspring size after controlling for maternal size. Within species, maternal size showed a positive correlation with both offspring size and number. Despite this consistency, no correlation between offspring size and number was found. After controlling for maternal size, however, offspring size and number showed a significant negative correlation. A phylogenetic component of our analysis accounted for little heterogeneity in the data, suggesting that our findings show remarkable consistency across taxa. Overall, our results support an observable phenotypic trade-off between offspring size and number. However, this analysis also highlights the importance of considering quality when examining trade-offs, a task that is not always straightforward as quality is context dependant.
Data from: Quantifying individual heterogeneity and its influence on life-history trajectories: different methods for different questions and contexts
Heterogeneity among individuals influences the life-history trajectories we observe at the population level because viability selection, selective immigration and emigration processes, and ontogeny change the proportion of individuals with specific trait values with increasing age. Here, we review the two main approaches that have been proposed to account for these processes in life-history trajectories, contrasting how they quantify ontogeny and selection, and proposing ways to overcome some of their limitations. Nearly all existing approaches to model individual heterogeneity assume either a single normal distribution or a priori known groups of individuals. Ontogenetic processes, however, can vary across individuals through variation in life-history tactics. We show the usefulness of describing ontogenetic processes by modelling trajectories with a mixture model that focuses on heterogeneity in life-history tactics. Additionally, most methods examine individual heterogeneity in a single trait, ignoring potential correlations among multiple traits caused by latent common sources of individual heterogeneity. We illustrate the value of using a joint modelling approach to assess the presence of a shared latent correlation and its influence on life-history trajectories. We contrast the strengths and limitations of different methods for different research questions, and we exemplify the differences among methods using empirical data from long-term studies of ungulates.
Data from: Demographic variability and heterogeneity among individuals within and among clonal bacteria strains
Identifying what drives individual heterogeneity has been of long interest to ecologists, evolutionary biologists and biodemographers, because only such identification provides deeper understanding of ecological and evolutionary population dynamics. In natural populations one is challenged to accurately decompose the drivers of heterogeneity among individuals as genetically fixed or selectively neutral. Rather than working on wild populations we present here data from a simple bacterial system in the lab, Escherichia coli. Our system, based on cutting-edge microfluidic techniques, provides high control over the genotype and the environment. It therefore allows to unambiguously decompose and quantify fixed genetic variability and dynamic stochastic variability among individuals. We show that within clonal individual variability (dynamic heterogeneity) in lifespan and lifetime reproduction is dominating at about 82–88%, over the 12–18% genetically (adaptive fixed) driven differences. The genetic differences among the clonal strains still lead to substantial variability in population growth rates (fitness), but, as well understood based on foundational work in population genetics, the within strain neutral variability slows adaptive change, by enhancing genetic drift, and lowering overall population growth. We also revealed a surprising diversity in senescence patterns among the clonal strains, which indicates diverse underlying cell-intrinsic processes that shape these demographic patterns. Such diversity is surprising since all cells belong to the same bacteria species, E. coli, and still exhibit patterns such as classical senescence, non-senescence, or negative senescence. We end by discussing whether similar levels of non-genetic variability might be detected in other systems and close by stating the open questions how such heterogeneity is maintained, how it has evolved, and whether it is adaptive.
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.