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.
690
datasets available to search
ShareScore release 0.9.0
Dataset results
690 results for “free-living”
FIGURE 14 in Four new species of free-living nematodes from shallow continental shelf of Portugal
FIGURE 14. Stylotheristus multipapillatus sp. n. holotype male: (A) anterior region (cephalic arrangement, amphideal fovea and buccal cavity), (B) copulatory apparatus (spicule and gubernaculum), (C) tail, (D) precloacal supplements and copulatory apparatus (spicule and gubernaculum), (E) testis.
FIGURE 11 in Four new species of free-living nematodes from shallow continental shelf of Portugal
FIGURE 11. Odontophora sinapophysis sp. n. paratype female: (A) anterior end (cephalic and subcephalic arrangement, buccal cavity and amphideal fovea), (B) vulva region (mass of sperm), (C) reproductive system, (D) tail.
FIGURE 4 in A new free-living marine nematode, Polkepsilonema arabicensis sp. n. (Desmodorida: Epsilonematidae), from Lakshadweep, India
FIGURE 4. Polkepsilonema arabicensis sp. n. photomicrographs of the cephalic capsule of a) holotype, b) paratype (WN2693), c) paratype (WN2694); d) paratype (WN2695); e) & f) paratype male (WN2691) at different focus. Scale bar: a–f = 10 µm.
FIGURE 1 in A new free-living marine nematode, Polkepsilonema arabicensis sp. n. (Desmodorida: Epsilonematidae), from Lakshadweep, India
FIGURE 1. Polkepsilonema arabicensis sp. n. collection site (marked in triangle) at Agatti island, Lakshadweep, India.
FIGURE 3 in A new free-living marine nematode, Polkepsilonema arabicensis sp. n. (Desmodorida: Epsilonematidae), from Lakshadweep, India
FIGURE 3. Polkepsilonema arabicensis sp. n. photomicrographs of a) holotype male, b) paratype female (WN2692), c) paratype female (WN2693); holotype d) spicule & e) gubernaculum (lateral view); f) cuticular anastomoses; g) cuticular structure and spines at body curvatures of holotype; h) straight ambulatory setae marked with arrows of holotype; i) copulatory thorns of paratype male (WN2691); j) dorsal and ventrosublateral teeth of paratype (WN2694); k) hyaline outer layer as spiny projections at curvature level of paratype (WN2695); l) straight ambulatory setae of paratype (WN2695); m) copulatory thorns of holotype; n) bisinous ambulatory setae of paratype (WN2693). Scale bar: a & b = 50 µm, c = 20 µm, d–n = 10 µm.
FIGURE 2 in A new free-living marine nematode, Polkepsilonema arabicensis sp. n. (Desmodorida: Epsilonematidae), from Lakshadweep, India
FIGURE 2. Polkepsilonema arabicensis sp. n. habitus of a) holotype male (WN2690) and b) paratype female (WN2692). Anterior end of c) holotype, d) paratype female (WN2692) and e) juvenile paratype (WN2694). f) spicule, gubernaculum (lateral view) and tail of holotype, g) copulatory thorns of holotype, h) & i) fine setae at 1st and 2nd body curvatures, j) vulval morphology. ppv: pars proximalis vaginae, prv: pars refringens vaginae. Scale bar: a & b = 50 µm, c–j = 10 µm.
Evening locomotor activity during stopover differs on pre-departure and departure days in free-living songbirds
The length of time songbirds remain at a migratory stopover site is likely regulated by a daily stay/go decision informed by fat stores and weather conditions, but the finer-scale timing of this decision and associated pre-departure behaviours are still poorly understood. Using automated radiotelemetry of free-living songbirds captured at a migratory stopover site in spring, we tested whether individuals change their locomotor activity near sunset on their migratory departure day compared to their non-departure days. To do so, we extracted precise transition times between diurnal activity and nocturnal inactivity, which always precedes departure, using changepoint analysis of radio transmission signal strength. Among four warbler species, individuals extended diurnal activity by 8-19 minutes towards sunset on their departure day. In three species, this extension was significant. In contrast, white-throated sparrows significantly shortened diurnal activity on their departure day by 13 min, also towards sunset. This is the first study to detect and quantify a change in locomotor activity schedule on departure versus non-departure days in free-living songbirds, and is consistent with the hypothesis that birds engage in pre-departure preparatory behaviours near sunset.
Data from: Estimating body mass of free-living whales using aerial photogrammetry and 3D volumetrics
1. Body mass is a key life history trait in animals. Despite being the largest animals on the planet, no method currently exists to estimate body mass of free-living whales. 2. We combined aerial photographs and historical catch records to estimate the body mass of free-living right whales (Eubalaena sp.). First, aerial photogrammetry from unmanned aerial vehicles was used to measure the body length, width (lateral distance) and height (dorso-ventral distance) of free-living southern right whales (E. australis; 48 calves, 7 juveniles and 31 lactating females). From these data, body volume was estimated by modelling the whales as a series of infinitely small ellipses. The body girth of the whales was next calculated at three measurement sites (across the pectoral fin, the umbilicus and the anus) and a linear model was developed to predict body volume from the body girth and length data. To obtain a volume-to-mass conversion factor, this model was then used to estimate the body volume of eight lethally caught North Pacific right whales (E. japonica), for which body mass was measured. This conversion factor was consequently used to predict the body mass of the free-living whales. 3. The cross-sectional body shape (height-width ratio) of the whales was slightly flattened dorso-ventrally at the anterior end of the body, almost circular in the mid region, and significantly flattened in the lateral plane across the posterior half of the body. Compared to a circular cross-sectional model, our body mass model incorporating body length, width and height improved mass estimates by up to 23.6% (mean=6.1%, SD=5.27). Our model had a mean error of only 1.6% (SD=0.012), compared to 9.5% (SD=7.68) for a simpler body length-to-mass model. The volume-to-mass conversion factor was estimated at 754.63kg m-3 (SD=50.03). Predicted body mass estimates were within a close range of existing body mass measurements. 4. We provide a non-invasive method to accurately estimate body mass of free-living whales while accounting for both their structural size (body length) and relative body condition (body width). Our approach can be directly applied to other marine mammals by adjusting the model parameters (body mass model script provided).
Data from: Social context alters spatial memory performance in free-living male prairie voles
<p>Spatial memory is crucial for mating success because it enables males to locate potential mates and potential competitors in space. Intraspecific competition and its varying intensity under certain conditions are potentially important for shaping spatial memory. For example, spatial memory could enable males to know where competitors are (contest competition), it could help males find mating partners (scramble competition), or both. We manipulated the intensity of intraspecific competition in two distinct contexts by altering the operational sex ratio of prairie voles (<i>Microtus ochrogaster</i>) living in outdoor enclosures by creating male- and female-biased sex ratios. After living freely under these contexts for four weeks, we compared males' performance in a laboratory spatial memory test. Males in the male-biased context demonstrated better spatial memory performance than males in the female-biased context. Notably, these data show that in spite of experiencing equally complex<i>spatial</i>contexts (i.e., natural outdoor enclosures), it was the <i>social </i>context that influenced spatial cognition, and it did so in a manner consistent with the hypothesis that spatial memory is particularly relevant for male-male interactions. Attached are the supporting data for this project.</p>
Data from: Data for: Variation in animal personality traits across a metal pollution gradient in a free-living songbird
Anthropogenic contaminants could alter traits central to animal behavioral types, or personalities, including aggressiveness, boldness and activity level. Lead and other toxic metals are persistent inorganic pollutants that affect organisms worldwide. Metal exposure can alter behavior by affecting neurology, endocrinology, and health. However, the direction and magnitude of the behavioral effects of metal exposure remain equivocal. Moreover, the degree to which metal exposure simultaneously affects suites of correlated behavioral traits (behavioral syndromes) that are controlled by common mechanisms remains unclear, with most studies focusing on single behaviors. Using a model species for personality variation, the great tit (Parus major), we explored differences in multiple behavioral traits across a pollution gradient where levels of metals, especially lead and cadmium, are elevated close to a smelter. We employed the novel environment exploration test, a proxy for variation in personality type, and also measured territorial aggressiveness and nest defense behavior. At polluted sites birds of both sexes displayed slower exploration behavior, which could reflect impaired neurological or physiological function. Territorial aggression and nest defense behavior were individually consistent, but did not vary with proximity to the smelter, suggesting that metal exposure does not concurrently affect exploration and aggression. Rather, exploration behavior appears more sensitive to metal pollution. Effects of metal pollution on exploration behavior, a key animal personality trait, could have critical effects on fitness.
Data from: A new solitary free-living species of the genus Sphenopus (Cnidaria: Anthozoa: Zoantharia: Sphenopidae) from Okinawa-jima Island, Japan
A new species of free-living solitary zoantharian is described from Okinawa, Japan. Sphenopus exilis sp. n. occurs on silty seafloors in Kin Bay and Oura Bay on the east coast of Okinawa-jima Island. Sphenopus exilis sp. n. is easily distinguished from other Sphenopus species by its small polyp size and slender shape, although there were relatively few differences between Sphenopus exilis sp. n. and S. marsupialis in the molecular phylogenetic analyses. Currently, very little is known about the ecology and diversity of Sphenopus species. Thus, reviewing each species carefully via combined morphological and molecular analyses by using newly obtained specimens from type localities is required to clearly understand and distinguish the species within the genus Sphenopus.
Data from: Individuals' expected genetic contributions to future generations, reproductive value, and short-term metrics of fitness in free-living song sparrows (Melospiza melodia)
Appropriately defining and enumerating 'fitness' is fundamental to explaining and predicting evolutionary dynamics. Yet, general theoretical concepts of fitness are often hard to translate into quantities that can be measured in wild populations experiencing complex environmental, demographic, genetic and selective variation. While the 'fittest' entities might be widely understood to be those that ultimately leave most descendants at some future time, such long-term legacies can rarely be measured, impeding evaluation of the degree to which tractable short-term metrics of individual fitness could potentially serve as useful direct proxies. One opportunity for conceptual and empirical convergence stems from the principle of individual reproductive value (Vi), defined as the number of copies of each of an individual's alleles that is expected to be present in future generations given the individual's realised pedigree of descendants. Since Vi tightly predicts an individual's longer-term genetic contribution, quantifying Vi provides a tractable route to quantifying what, to date, has been an abstract theoretical fitness concept. We used complete pedigree data from free-living song sparrows (Melospiza melodia) to demonstrate that individuals' expected genetic contributions stabilise within an observed 20-year (i.e. ~8 generation) time period, allowing estimation of individual Vi. Considerable among-individual variation in Vi was evident in both sexes. Standard metrics of individual lifetime fitness, comprising lifespan, lifetime reproductive success and projected growth rate, typically explained less than half the variation. We thereby elucidate the degree to which fitness metrics observed on individuals concur with measures of longer-term genetic contributions, and consider the degree to which analyses of pedigree structure could provide useful complementary insights into evolutionary outcomes.
Data from: Daily foraging patterns in free-living birds: exploring the predation-starvation trade-off
Daily patterns in the foraging behaviour of birds are assumed to balance the counteracting risks of predation and starvation. Predation risks are a function of the influence of weight on flight performance and foraging behaviours that may expose individuals to predators. Although recent research sheds light on daily patterns in weight gain, little data exist on daily foraging routines in free-living birds. In order to test the predictions of various hypotheses about daily patterns of foraging, we quantified the activity of four species of passerines in winter using radio frequency identification receivers built into supplemental feeding stations. From records of 472,368 feeder visits by tagged birds, we found that birds generally started to feed before sunrise and continued to forage at a steady to increasing rate throughout the day. Foraging in most species terminated well before sunset, suggesting their desired level of energy reserves was being reached before the end of the day. These results support the risk-spreading theorem over a long-standing hypothesis predicting bimodality in foraging behaviour purportedly driven by a tradeoff between the risks of starvation and predation. Given the increased energetic demands experienced by birds during colder weather, our results suggest that birds' perceptions of risk are biased towards starvation avoidance in winter.
Data from: Artificial light at night does not affect telomere shortening in a developing free-living songbird: a field experiment
Artificial light at night (ALAN) is an increasingly pervasive anthropogenic disturbance factor. ALAN can seriously disrupt physiological systems that follow circadian rhythms, and may be particularly influential early in life, when developmental trajectories are sensitive to stressful conditions. Using great tits (Parus major) as a model species, we experimentally examined how ALAN affects physiological stress in developing nestlings. We used a repeated-measure design to assess effects of ALAN on telomere shortening, body mass, tarsus length and body condition. Telomeres are repetitive nucleotide sequences that protect chromosomes from damage and malfunction. Early life telomere shortening can be accelerated by environmental stressors, and has been linked to later-life declines in survival and reproduction. We also assayed nitric oxide, as an additional metric of physiological stress, and determined fledging success. Change in body condition between day 8 and 15 differed according to treatment. Nestlings exposed to ALAN displayed a trend towards a decline in condition, whereas control nestlings displayed a trend towards increased condition. This pattern was driven by a greater increase in tarsus length relative to mass in nestlings exposed to ALAN. Nestlings in poorer condition and nestlings that were smaller than their nest mates had shorter telomeres. However, exposure to ALAN was unrelated to telomere shortening, and also had no effect on nitric oxide concentrations or fledging success. Thus, exposure to ALAN may not have led to sufficient stress to induce telomere shortening. Indeed, plasticity in other physiological systems could allow nestlings to maintain telomere length despite moderate stress. Alternatively, the cascade of physiological and behavioral responses associated with light exposure may have no net effect on telomere dynamics.
Data from: Stressful colors: corticosterone concentrations in a free-living songbird vary with the spectral composition of experimental illumination
Organisms have evolved under natural daily light/dark cycles for millions of years. These cycles have been disturbed as night-time darkness is increasingly replaced by artificial illumination. Investigating the physiological consequences of free-living organisms in artificially lit environments is crucial to determine whether nocturnal lighting disrupts circadian rhythms, changes behaviour, reduces fitness and ultimately affects population numbers. We make use of a unique, large-scale network of replicated field sites which were experimentally illuminated at night using lampposts emanating either red, green, white or no light to test effect on stress hormone concentrations (corticosterone) in a songbird, the great tit (Parus major). Adults nesting in white-light transects had higher corticosterone concentrations than in the other treatments. We also found a significant interaction between distance to the closest lamppost and treatment type: individuals in red light had higher corticosterone levels when they nested closer to the lamppost than individuals nesting farther away, a decline not observed in the green or dark treatment. Individuals with high corticosterone levels had fewer fledglings, irrespective of treatment. These results show that artificial light can induce changes in individual hormonal phenotype. As these effects vary considerably with light spectrum, it opens the possibility to mitigate these effects by selecting street lighting of specific spectra.
Data from: Inbreeding depression by environment interactions in a free-living mammal population
Experimental studies often find that inbreeding depression is more severe in harsh environments, but the few studies of in situ wild populations available to date rarely find strong support for this effect. We investigated evidence for inbreeding depression by environment interactions in nine traits in the individually monitored Soay sheep population of St Kilda, using genomic inbreeding coefficients based on 37 037 single-nucleotide polymorphism loci, and population density as an axis of environmental variation. All traits showed variation with population density and all traits showed some evidence for depression because of either an individual's own inbreeding or maternal inbreeding. However, only six traits showed evidence for an interaction in the expected direction, and only two interactions were statistically significant. We identify three possible reasons why wild population studies may generally fail to find strong support for interactions between inbreeding depression and environmental variation compared with experimental studies. First, for species with biparental inbreeding only, the amount of observed inbreeding in natural populations is generally low compared with that used in experimental studies. Second, it is possible that experimental studies sometimes actually impose higher levels of stress than organisms experience in the wild. Third, some purging of the deleterious recessive alleles that underpin interaction effects may occur in the wild.
Data from: Heterogeneity of genetic architecture of body size traits in a free-living population
Knowledge of the underlying genetic architecture of quantitative traits could aid in understanding how they evolve. In wild populations, it is still largely unknown whether complex traits are polygenic or influenced by few loci with major effect, due to often small sample sizes and low resolution of marker panels. Here, we examine the genetic architecture of five adult body size traits in a free-living population of Soay sheep on St Kilda using 37 037 polymorphic SNPs. Two traits (jaw and weight) show classical signs of a polygenic trait: the proportion of variance explained by a chromosome was proportional to its length, multiple chromosomes and genomic regions explained significant amounts of phenotypic variance, but no SNPs were associated with trait variance when using GWAS. In comparison, genetic variance for leg length traits (foreleg, hindleg and metacarpal) was disproportionately explained by two SNPs on chromosomes 16 (s23172.1) and 19 (s74894.1), which each explained >10% of the additive genetic variance. After controlling for environmental differences, females heterozygous for s74894.1 produced more lambs and recruits during their lifetime than females homozygous for the common allele conferring long legs. We also demonstrate that alleles conferring shorter legs have likely entered the population through a historic admixture event with the Dunface sheep. In summary, we show that different proxies for body size can have very different genetic architecture and that dense SNP helps in understanding both the mode of selection and the evolutionary history at loci underlying quantitative traits in natural populations.
FIGURE 6. S. conicauda n in Two new free-living nematode species (Comesomatidae) from the continental slope of New Zealand, with keys and notes on distribution
FIGURE 6. S. conicauda n. sp. A. Male posterior body region showing copulatory apparatus. B. Female posterior body region. C. Female mid-body and posterior body regions showing vulva, genital branches, and intracellular inclusions in gut wall. Scale bar: A, B = 30 Μm; C = 100 Μm.
FIGURE 2. V. a u r a t a n in Two new free-living nematode species (Comesomatidae) from the continental slope of New Zealand, with keys and notes on distribution
FIGURE 2. V. a u r a t a n. sp. Male. A. Lateral view of neck region. B. Lateral surface view of head. C. Ventral view of head showing buccal cavity and teeth. D. Entire body. Scale bar: A = 40 Μm; B, C = 25 Μm; D = 290 Μm.
FIGURE 3 V. a in Two new free-living nematode species (Comesomatidae) from the continental slope of New Zealand, with keys and notes on distribution
FIGURE 3 V. a ur a t a n. sp. A. Male posterior body region showing copulatory apparatus B. Female posterior body region showing chords. C. Mid-region of female body showing vulva and genital branches. Scale bar: A, B = 50 Μm; C = 145 Μm.
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.