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1,288 results for “threatened”
Data from: Floral display and habitat fragmentation: effects on the reproductive success of the threatened mass-flowering Conospermum undulatum (Proteaceae)
1. Fragmentation of natural vegetation is currently one of the largest threats to plant populations and their interactions with pollinators. Plant reproductive susceptibility to habitat fragmentation has been investigated in many species; however, the response of wild mass-flowering species is poorly known, with research limited to mainly boreal plant species. 2. Here we studied twelve remnant populations of the threatened mass-flowering shrub Conospermum undulatum in the southwest Australian biodiversity hotspot, each presenting different population size, level of isolation, and floral display. We assessed the impact of fragmentation on: 1) fruit and seed production; and 2) seed germination. To gain a deeper understanding of factors influencing the reproductive success of C. undulatum we performed pollinator exclusion and self-pollination treatments to experimentally assess the mating system of this threatened shrub. 3. We found C. undulatum to be strictly self-incompatible and totally reliant on pollinators visiting with an outcrossed pollen load to complete the reproductive cycle. Further, we found that fruit production significantly decreased with decreasing floral display. A decrease in population size and floral display led to a decrease in seed output, while increasing isolation also led to a reduced production of seeds. Overall, seed germination was positively related to population size, and a negative relationship was found between germination and isolation. 4. Our results demonstrate the important relationship between pollinators and floral morphology in plants of southwest Australia that have coevolved with native pollinators and developed characteristic flower morphologies over long timeframes. The self-incompatible C. undulatum cannot rely on its mass-flowering trait to attract pollinators from co-flowering species, neither can it compensate for the lack of visitors by promoting geitonogamy. Consequently, fragmentation has a significant effect on the reproductive output of C. undulatum, and size, isolation, and floral display of populations should be considered when planning conservation actions for the species.
Data from: An integrated population model for estimating the relative effects of natural and anthropogenic factors on a threatened population of steelhead trout
<p>This collection includes data on the abundance, age composition, and harvest of adult steelhead trout, as well as the numbers of juveniles released from a hatchery, for steelhead trout (<em>Oncorhyncus mykiss</em>) from the Skagit River in Washington, USA. It also includes estimates of the marine survival of hatchery-origin steelhead.</p>
Data From: Characterizing patterns of genomic variation in the threatened Utah prairie dog: implications for conservation and management
<p>Utah prairie dogs (<i>Cynomys parvidens</i>) are federally threatened due to eradication campaigns, habitat destruction, and outbreaks of plague. Today, Utah prairie dogs exist in small, isolated populations, making them less demographically stable and more susceptible to erosion of genetic variation by genetic drift. We characterized patterns of genetic structure at neutral and putatively adaptive loci in order to evaluate the relative effects of genetic drift and local adaptation on population divergence. We sampled individuals across the Utah prairie dog species range and generated 2,955 single nucleotide polymorphisms (SNPs) using double digest restriction site associated DNA sequencing (ddRAD). Genetic diversity was lower in low elevation sites compared to high elevation sites. Population divergence was high among sites and followed an isolation-by-distance (IBD) model. Our results indicate that genetic drift plays a substantial role in the population divergence of the Utah prairie dog, and colonies would likely benefit from translocation of individuals between recovery units, which are characterized by distinct elevations, despite the detection of environmental associations with outlier loci. By understanding the processes that shape genetic structure, better informed decisions can be made with respect to the management of threatened species to ensure that adaptation is not stymied.</p>
FIGURE 4 in Advertisement call of two threatened red-bellied-toads Melanophryniscus cambaraensis and M. macrogranulosus (Anura: Bufonidae), from the Atlantic Rainforest, southern Brazil
FIGURE 4. Comparison between populations of parameters selected by PCA (box plot: mean, SD and range).
FIGURE 1 in Advertisement call of two threatened red-bellied-toads Melanophryniscus cambaraensis and M. macrogranulosus (Anura: Bufonidae), from the Atlantic Rainforest, southern Brazil
FIGURE 1. Data collection of Melanophryniscus cambaraensis, in FLONA SFP (1) and M. macrogranulosus, in Garapiá (2) and Morro da Gruta (3) in Rio Grande do Sul, south Brazil.
FIGURE 3 in Advertisement call of two threatened red-bellied-toads Melanophryniscus cambaraensis and M. macrogranulosus (Anura: Bufonidae), from the Atlantic Rainforest, southern Brazil
FIGURE 3. Oscillogram and spectrogram of Melanophryniscus cambaraensis call from FLONA SFP (A - FZ 9093) and a close view of the call (B); and a close view of the call of M. macrogranulosus from Garapiá (C – FZ9102) and from Morro da Gruta (D – FZ 9113). In each figure we show call part A (single pulses) and B (pulsed trill) of the call.
Data from: Designing monitoring protocols to measure population trends of threatened insects: a case study of the cryptic, flightless grasshopper Brachaspis robustus
<p>Statistically robust monitoring of threatened populations is essential for effective conservation management because the population trend data that monitoring generates is often used to make decisions about when and how to take action. Despite representing the highest proportion of threatened animals globally, the development of best practice methods for monitoring populations of threatened insects is relatively uncommon. Traditionally, population trend data for the Nationally Endangered New Zealand grasshopper <em>Brachaspis robustus</em> has been determined by counting all adults and nymphs seen on a single ~1.5 km transect searched once annually. This method lacks spatial and temporal replication, both of which are essential to overcome detection errors in highly cryptic species like <em>B</em>. <em>robustus</em>. It also provides no information about changes in the grasshopper's distribution throughout its range. Here, we design and test new population density and site occupancy monitoring protocols by comparing a) comprehensive plot and transect searches at one site and b) transect searches at two sites representing two different habitats (gravel road and natural riverbed) occupied by the species across its remaining range. Using power analyses, we determined a) the number of transects, b) the number of repeated visits and c) the grasshopper demographic to count to accurately detect long term change in relative population density. To inform a monitoring protocol design to track trends in grasshopper distribution, we estimated the probability of detecting an individual with respect to a) search area, b) weather and c) the grasshopper demographic counted at each of the two sites. Density estimates from plots and transects did not differ significantly. Population density monitoring was found to be most informative when large adult females present in early summer were used to index population size. To detect a significant change in relative density with power > 0.8 at the gravel road habitat, at least seventeen spatial replicates (transects) and four temporal replicates (visits) were required. Density estimates at the natural braided river site performed poorly and likely require a much higher survey effort. Detection of grasshopper presence was highest (<em>p</em><sub><em>g</em></sub> > 0.6) using a 100 m x 1 m transect at both sites in February under optimal (no cloud) conditions. At least three visits to a transect should be conducted per season for distribution monitoring. Monitoring protocols that inform the management of threatened species are crucial for better understanding and mitigation of the current global trends of insect decline. This study provides an exemplar of how appropriate monitoring protocols can be developed for threatened insect species.</p>
Steep topography buffers threatened gymnosperm species against anthropogenic pressures in China
China is one of the most species-rich countries in the world, harbouring many rare gymnosperms. Following recent human-led loss of forests, China is now experiencing increases in forest cover resulting from efforts of reforestation-schemes. As anthropogenic activities have previously been found to interact with topography in shaping forest cover in China and considering the large human population and the ongoing population increase of the country, it is important to understand the role of anthropogenic pressures relative to environmental drivers for shaping species distributions here. Based on the well-established relationship between human population density and topography, we propose a hypothesis for explaining species distributions in a country dominated by human activities, predicting that species are more likely to occur in areas of steep topography under medium human population densities compared to low- and high human population densities. Using species occurrence data from the Chinese Vascular Plant Distribution Database along with a common SDM method (Maximum Entropy Modelling) we tested this hypothesis. Our results show that steep topography has the highest importance for predicting Chinese gymnosperm species occurrences in general, and threatened species specifically, in areas of medium human population densities. Consequently, these species are more often found in areas of steep terrain, supporting the proposed hypothesis. Results from this study highlight the need to include topographically heterogeneous habitats when planning new protected areas for species conservation.
Genetic diversity in the threatened freshwater mussel Lampsilis powellii
<p>North America is home to the greatest share of the world's freshwater mussel diversity; however, over 70% of its ~300 species are endangered or threatened. Lampsilis powellii, the Arkansas Fatmucket, is endemic to Arkansas and now restricted to upstream reaches of the Ouachita and Saline rivers, but the species is declining within this small range. Conservation actions such as augmenting or reintroducing populations may be necessary, but they require knowledge of the distribution of genetic variation within and among extant populations. We analyzed population structure between the South Fork Ouachita River and Saline River using a 607 base pair region of the mitochondrial COI gene and 14 microsatellites designed for Lampsilis abrupta. COI sequences showed little variation and the most common haplotype was present in both rivers. Our mtDNA sequences were indistinguishable from those of L. siliquoidea deposited on GenBank, but we were unable to make conclusions about the taxonomic distinctiveness of L. powellii. Microsatellites showed heterozygote deficiency for most loci and revealed little evidence of population structure between the two rivers. Overall, our results show low genetic diversity in L. powellii, which may reflect its small population size due to its long history of geographic isolation compounded by anthropogenic habitat destruction and fragmentation. Further genetic analyses of lampsiline taxa is needed to establish species limits for Lampsilis in the Interior Highlands.</p>
FIGURE 6 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 6. Asulcate (left) and sulcate (right) faces of the fully everted and maximally expanded right hemipenis of the paratype of Helicops phantasma (MZUSP 19319), from the municipality of Carolina, state of Maranh"o, Brazil. Scale bar = 10 mm
FIGURE 7 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 7. Asulcate (right) and sulcate (left) faces of the fully everted and maximally expanded right hemipenis of Helicops leopardinus (UFMT-R 1504) from the municipality of Cuiabá, state Mato Grosso, Brazil (above), and Helicops danieli (AMNH 97461), from state of Bolivar, Colombia. Scale bars = 10 mm.
FIGURE 5 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 5. Localities of record of Helicops phantasma [black (type locality) and white triangles] and of the present sample of He. leopardinus (black circles). Crosses denote areas of hydroelectric dams already installed or projected to the future in the Tocantins-Araguaia Basin. Gray shading illustrates the main hydrographic basins of Central and Northern Brazil (1: Amazon Basin; 2: Tocantins-Araguaia Basin; 3: Atlantico Norte and Nordeste Basins; 4 S"o Francisco Basin; 5: Atlantico Leste Basin, and 6: Paraná Basin).
FIGURE 4 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 4. Dorsal, lateral, and ventral views of the head of the holotype of Helicops phantasma sp. nov. (UFMT-R 8290) from the region of the municipality of Barra do Garças, state of Mato Grosso, Brazil. Scale bar = 10 mm.
FIGURE 3 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 3. Dorsal and ventral views of the holotype of Helicops phantasma sp. nov. (UFMT-R 8290), from the region of the municipality of Barra do Garças, state of Mato Grosso, Brazil. Scale bar = 40 mm.
FIGURE 1 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 1. Illustrations of the syntypes of (A) Helicops leopardinus (Schlegel, 1837) [modified from Jan & Sordelli (1864: f. 2, pl. III)] and (B–C) He. leprieurii Duméril et al., 1854, a junior synonym [modified from Jan & Sordelli (1864: f. 2–3, pl. IV). In both cases, the dorsal pattern consists of rounded black spots.
FIGURE 2 in Long known, brand new, and possibly threatened: a new species of watersnake of the genus Helicops Wagler, 1828 (Serpentes; Xenodontinae) from the Tocantins- Araguaia River Basin, Brazil
FIGURE 2. Phylogenetic relationships of Hydropsini (one species of Hydrops, one species of Pseudoeryx, and 11 species of Helicops) based on a concatenated matrix of the 12S, 16S, BDNF, C-mos, and NT3 sequence data. Numbers at nodes indicate the values of Bayesian Credibility/Maximum Likelihood bootstrap. The bar represents the number of expected changes per site in the Bayesian Analysis. Terminal H1733 corresponds to the voucher MZUSP 19695. The name Helicops pictiventris is currently in the synonymy of He. infrataeniatus, but appears in the tree exactly as the pertinent sequences appear in the GenBank (see Zaher et al. 2009).
Reproductive success of the threatened San Clemente Bell's Sparrow in recovering habitats is similar to success in historical habitat
<p>The San Clemente Bell's Sparrow <i>Artemisiospiza belli clementeae</i> is a federally threatened subspecies endemic to San Clemente Island, California. Previous research suggested dependence on boxthorn (<i>Lycium californicum</i>) as breeding habitat and nesting substrate; however, this conclusion was based on data collected when introduced feral ungulates had severely degraded the soil and vegetation cover. Since removal of the ungulates, native vegetation has gradually increased and the San Clemente Bell's Sparrows have expanded into areas where habitat had been unsuitable. To explore how Bell's Sparrows use these areas, we examined reproductive metrics associated with habitat covariates gathered at 214 nest sites used by Bell's Sparrows from 2014 ̶ 2016. We found that nest success in boxthorn habitat, previously considered an essential habitat for Bell's Sparrow nesting, was similar to success in alternative habitat types. Our findings contradict previous conclusions that Bell's Sparrows were boxthorn-dependent. We believe this previously documented relationship was likely due to the lack of available alternative nesting habitat following years of feral ungulate degradation, and Bell's Sparrows now reproduce in multiple habitat types and throughout most of San Clemente Island. Furthermore, our findings illustrate the importance of long-term monitoring and corresponding adaptive management when monitoring species in changing and recovering landscapes.The San Clemente Bell's Sparrow <i>Artemisiospiza belli clementeae</i> is a federally threatened subspecies endemic to San Clemente Island, California. Previous research suggested dependence on boxthorn (<i>Lycium californicum)</i> as breeding habitat and nesting substrate; however, this conclusion was based on data collected when introduced feral ungulates had severely degraded the soil and vegetation cover. Since removal of the ungulates, native vegetation has gradually increased and the San Clemente Bell's Sparrows have expanded into areas where habitat had been unsuitable. To explore how Bell's Sparrows use these areas, we examined reproductive metrics associated with habitat covariates gathered at 214 nest sites used by Bell's Sparrows from 2014 ̶ 2016. We found that nest success in boxthorn habitat, previously considered an essential habitat for Bell's Sparrow nesting, was similar to success in alternative habitat types. Our findings contradict previous conclusions that Bell's Sparrows were boxthorn-dependent. We believe this previously documented relationship was likely due to the lack of available alternative nesting habitat following years of feral ungulate degradation, and Bell's Sparrows now reproduce in multiple habitat types and throughout most of San Clemente Island. Furthermore, our findings illustrate the importance of long-term monitoring and corresponding adaptive management when monitoring species in changing and recovering landscapes.</p>
Rear-edge populations are important for understanding climate change risk and adaptation potential of threatened species
<p>Climate change disproportionately threatens alpine species, by reducing available habitat and by isolating their populations. These pressures are particularly relevant for rear-edge populations, which typically occupy more marginal habitat compared to populations at the core of species' ranges. We studied Caucasian grouse <i>Lyrurus mlokosiewiczi</i> in the Caucasus ecoregion, a global biodiversity hotspot where this species is endemic, to understand potential climate change impacts on the species. Specifically, we assessed how climate change impacts rear-edge populations and how important these populations are for understanding range shifts and adaptive capacity under climate change. We used maximum entropy modelling to assess changes in the distribution of climatically-suitable habitat under present and 2070 climate conditions for the representative concentration pathways 8.5 (RCP8.5). Our results revealed that ignoring rear-edge populations leads to a significant underestimation of the future range (by about 14,700 km²). Rear-edge populations were better adapted to warmer climates compared to core populations, and ignoring them therefore also underestimates adaptive capacity. Preventing the loss of rear-edge populations should therefore be a priority for conservation planning in the face of climate change. Because the Caucasian grouse is associated with alpine mountain tops, conservation should focus on establishing connectivity between rear-edge and core populations (e.g., via transboundary corridors or assisted colonizations). Our study reveals how species distribution modelling can highlight the importance of rear-edge populations for mitigating climate change impacts on species of conservation concern.</p>
Data from: Genetic assessment of population structure and connectivity in the threatened Mediterranean coral Astroides calycularis (Scleractinia, Dendrophylliidae) at different spatial scales
Understanding dispersal patterns, population structure and connectivity among populations is helpful in the management and conservation of threatened species. Molecular markers are useful tools as indirect estimators of these characteristics. In this study we assess the population genetic structure of the endemic Mediterranean coral Astroides calycularis in the Alboran Sea at local and regional scales, and at three localities outside of this basin. Bayesian clustering methods, traditional F-statistics and Dest statistics were used to determine the patterns of genetic structure. Likelihood and coalescence approaches were used to infer migration patterns and effective population sizes. The results obtained reveal a high level of connectivity among localities separated by as much as one kilometer and moderate levels of genetic differentiation among more distant localities, somewhat corresponding with a stepping-stone model of gene flow and connectivity. These data suggest that connectivity among populations of this coral is mainly driven by the biology of the species, with low dispersal abilities; in addition, hydrodynamic processes, oceanographic fronts and the distribution of rocky substrate along the coastline may influence larval dispersal.
Data from: Intricate trophic links between threatened vertebrates confined to a small island in the Atlantic Ocean
Trophic networks in small isolated islands are in a fragile balance, and their disturbance can easily contribute towards the extinction vortex of species. Here we show, in a small Atlantic island (Raso) in the Cabo Verde Archipelago, using DNA metabarcoding, the extent of trophic dependence of the Endangered giant wall gecko Tarentola gigas on endemic populations of vertebrates, including one of the rarest bird species of the world, the Critically Endangered Raso lark Alauda razae. We found that the Raso lark (27%), Iago sparrow Passer iagoensis (12%), Bulwer's petrel Bulweria bulwerii (15%) and the Cabo Verde shearwater Calonectris edwardsii (10%) are the most frequent vertebrate signatures found in the faeces of the giant wall gecko. This work provides the first integrative assessment of their trophic links, an important issue to be considered for the long-term conservation of these small and isolated island ecosystems.
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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.