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Luca Santini Nick J. B. Isaac Gentile Francesco Ficetola 《Global Ecology and Biogeography》2018,27(7):787-791
Motivation
Population density is a key demographic parameter influencing many ecological processes, and macroecology has described both intra‐ and interspecific patterns of variation. Population density data are expensive to collect and contain many forms of noise and potential bias; these factors have impeded investigation of macroecological patterns, and many hypotheses remain largely unexplored. Population density also represents fundamental information for conservation, because it underlies population dynamics and, ultimately, extinction risk. Here we present TetraDENSITY, an extensive dataset with > 18,000 records of density estimates for terrestrial vertebrates, in order to facilitate new research on this topic.Main types of variable contained
The dataset includes taxonomic information on species, population density estimate, year of data collection, season, coordinates of the locality, locality name, habitat, sampling method and sampling area.Spatial location and grain
Global. Spatial accuracy varies across studies; conservatively, it can be considered at 1°, but for many data it is much finer.Time period and grain
From 1926 to 2017. Temporal accuracy is yearly in most cases, but studies with higher temporal resolution (season, month) are also present.Major taxa and level of measurement
Amphibians in terrestrial phase, reptiles, birds and mammals. Estimates derive from multiple methods, reflecting the study taxon, location and techniques available at the time of density estimation. 相似文献3.
The first step towards the preservation of endangered species is to establish an appropriate ranking system, which assigns different nature conservation priority scores to different taxa. The system developed by Millsap et al. (Wildlife Monograph 1990, 111: 1–57) has been modified and applied to the mammal, bird, reptile, and amphibian species of Hungary. Three variable groups have been compiled, including eight (measuring biological characteristics), three (features of the Hungarian population) and five (evaluation of research and conservation actions) variables, respectively. In cooperation with several experts, we gave scores to all 379 taxa considered. The most endangered taxon proved to be the Hungarian Meadow Viper (Vipera ursinii rakosiensis), which occurs only in Hungary with just a few hundred individuals. The species rank depends on the availability and quality of data, so it is urgent to devote more effort to survey and monitoring projects. We present a possible application of the species list, where the taxa are grouped according to their legal status in Hungary (strictly protected, protected, partly protected and not protected), and the validity of this categorisation was tested by applying multivariate discriminant analysis. Only 58.36% of the species were correctly classified. The reasons for stronger than expected protection include popularity, attractiveness, and local rarity, while reasons for lower protection include preference for hunting and control of predators and pests. 相似文献
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Luca Santini Nick J. B. Isaac Luigi Maiorano Gentile Francesco Ficetola Mark A. J. Huijbregts Chris Carbone Wilfried Thuiller 《Global Ecology and Biogeography》2018,27(8):968-979
Aim
Although the effects of life history traits on population density have been investigated widely, how spatial environmental variation influences population density for a large range of organisms and at a broad spatial scale is poorly known. Filling this knowledge gap is crucial for global species management and conservation planning and to understand the potential impact of environmental changes on multiple species.Location
Global.Time period
Present.Major taxa studied
Terrestrial amphibians, reptiles, birds and mammals.Methods
We collected population density estimates for a range of terrestrial vertebrates, including 364 estimates for amphibians, 850 for reptiles, 5,667 for birds and 7,651 for mammals. We contrasted the importance of life history traits and environmental predictors using mixed models and tested different hypotheses to explain the variation in population density for the four groups. We assessed the predictive accuracy of models through cross‐validation and mapped the partial response of vertebrate population density to environmental variables globally.Results
Amphibians were more abundant in wet areas with high productivity levels, whereas reptiles showed relatively higher densities in arid areas with low productivity and stable temperatures. The density of birds and mammals was typically high in temperate wet areas with intermediate levels of productivity. The models showed good predictive abilities, with pseudo‐R2 ranging between 0.68 (birds) and 0.83 (reptiles).Main conclusions
Traits determine most of the variation in population density across species, whereas environmental conditions explain the intraspecific variation across populations. Species traits, resource availability and climatic stability have a different influence on the population density of the four groups. These models can be used to predict the average species population density over large areas and be used to explore macroecological patterns and inform conservation analyses. 相似文献5.
Emanuel H. Martin Vedasto G. Ndibalema Francesco Rovero 《African Journal of Ecology》2017,55(1):37-46
The increasing use of camera trapping coupled to occupancy analysis to study terrestrial mammals has opened the way to inferential studies that besides estimating the probability of presence explicitly consider detectability. This in turn allows considering factors that can potentially confound the estimation of occupancy and detection probability, including seasonal variations in rainfall. To address this, we conducted a systematic camera trapping survey in the Udzungwa Mountains of Tanzania by deploying twenty camera traps for 30 days in dry and wet seasons and used dynamic occupancy modelling to determine the effect of season on estimated occupancy and detection probability for species with >10 capture events. The sampling yielded 7657 and 6015 images in dry and wet seasons, respectively, belonging to 21 mammal species. Models with no season dependency and with season‐dependent detectability were best supported, indicating that neither colonization nor extinction varied with seasons and hence occupancy did not vary. Only bush pig (Potamochoerus larvatus) showed a significant decrease in detectability from dry to wet seasons. Our study indicates that seasonal variation in rainfall may have limited effect on occupancy and detectability of resident mammals in Udzungwa rainforests; however, it remains a factor to consider when designing future studies. 相似文献
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《Science activities》2013,50(4):123-128
Reptiles and amphibians are a diverse and interesting group of organisms. The four activities described in this article take students' curiosity into the realm of scientific understanding. The activities involve the concepts of species identification; animal adaptations, communication, and habitat; and conservation. 相似文献
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山西历山地区的两栖爬行动物 总被引:2,自引:1,他引:2
1993- 1997 年在山西历山地区对两栖和爬行动物进行了调查。此区共有两栖动物11 种, 隶2 目5 科8属, 其中, 古北界种3 种、东洋界种3 种、广布种5 种; 爬行动物24 种, 隶3 目7 科14 属, 其中, 古北界种7种、东洋界种12 种、广布种4 种、特有种1 种。 相似文献
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Projected Effects of Climate Change on Patterns of Vertebrate and Tree Species Richness in the Conterminous United States 总被引:5,自引:0,他引:5
David J. Currie 《Ecosystems》2001,4(3):216-225
General circulation models (GCM) predict that increasing levels of atmospheric carbon dioxide (CO2) and other greenhouse gases will lead to dramatic changes in climate. It is known that the spatial variability of species richness over continental spatial scales is strongly correlated with contemporary climate. Assuming that this relationship between species richness and climate persists under conditions of increased CO2, what changes could we expect to occur in terms of species richness? To address this question, I used observed relationships between contemporary richness and climate, coupled with climate projections from five GCM, to project these future changes. These models predict that the richness of vertebrate ectotherms will increase over most of the conterminous United States. Mammal and bird richness are predicted to decrease in much of the southern US and to increase in cool, mountainous areas. Woody plant richness is likely to increase throughout the North and West and to decrease in the southwestern deserts. These projections represent changes that are likely to occur over long time scales (millennia); short-term changes are expected to be mainly negative. 相似文献
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A taxonomic analysis of data reveals that there are more reptilian than amphibian species in Botswana and that the number of reptilian species generally decreases from the mesic north to the arid southern part of the country. Squamates (lizards and snakes) compose the majority of the reptilian fauna. An analysis of community reveals that the area of Botswana north of the 22° parallel is the most important in terms of faunal diversity, and thus special consideration in terms of fauna conservation and management is warranted. Results show that climatic conditions in Botswana have profound affects on the distribution of herpetofaunal species.
Une analyse taxonomique des données révèle qu'il y a plus d'espèces de reptiles que d'amphibiens au Botswana et que le nombre d'espèces de reptiles diminue généralement du nord vers le sud aride du pays. Les squamates (lézards et serpents) composent la majeure partie de la faune reptilienne. Une analyse des communautés révèle que la partie du Botswana au nord du 22e parallèle est la plus importante en terme de diversité faunistique et que ceci justifie une considération spéciale pour la conservation et la gestion de la faune. Les résultats montrent que les conditions climatiques au Botswana affectent profondément la distribution des espèces de reptiles. 相似文献
Résumé
Une analyse taxonomique des données révèle qu'il y a plus d'espèces de reptiles que d'amphibiens au Botswana et que le nombre d'espèces de reptiles diminue généralement du nord vers le sud aride du pays. Les squamates (lézards et serpents) composent la majeure partie de la faune reptilienne. Une analyse des communautés révèle que la partie du Botswana au nord du 22
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Juliane Pereira-Ribeiro Thais Linause Átilla C. Ferreguetti Jonathan Cozer Helena G. Bergallo Carlos Frederico D. Rocha 《Austral ecology》2023,48(7):1405-1412
Stream-dwelling amphibians' occurrence, behaviour and reproductive success are strongly influenced by dynamic abiotic factors, for example, water flow and spray. These factors can disproportionately affect these frogs due to their dependency on specific favourable conditions for development and incapacity to disperse from unfavourable environments. We analysed the influence of environmental covariates on the detectability of Crossodactylus gaudichaudii, an amphibian species endemic to streams in the Brazilian Atlantic Forest. We conducted sampling in the streams of the Duas Bocas Biological Reserve, Brazil, and we measured air and water temperature, air humidity and pH of water on each sampling occasion. We estimated the effects of variables on the detectability of the species using single-season occupancy models. Our results indicated that the detectability of the species increases on occasions with higher water temperatures (24–26°C) and lower pH (5.0–5.5). We investigated the influence of these covariates only on the detectability of adult frogs, but it is likely that the physiochemical properties of stream water are more important to aquatic larvae, and hence, the probability of their detection. Given this, further studies should examine the relevance of covariates on the detectability of adult frogs as well as larvae. 相似文献
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香港的两栖和爬行动物 总被引:1,自引:2,他引:1
香港及其附近水域已有纪录的两栖和爬行动物共4目23科70属107种。本文着重分析陆地与淡水产种类,计有4目21科63属98种,其中目前仅见于香港的特有种4种,物种密度高达897.4/104km2,东洋界种类占绝对优势,其中主要为南中国成分,其次为印度支那成分和印度马来成分,香港与我国东南沿海各省(区)具有很高的生物相似值(>0.4),在动物地理区划上属于东洋界华南区东南沿海亚区。香港地处北半球亚热带季风区,气候温暖湿润,雨量充沛,适合两栖爬行动物的生存和繁衍;但由于面积不大、地貌较不复杂,随着经济的发展和人口的增加,它们生存的地域越来越缩小,再加以人为的干扰,物种和数量有减少的趋势。 相似文献
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Road mortality of animals (roadkill) threatens public safety and wildlife populations. As mitigation tools, predictive models of roadkill are becoming more common in the published literature; however, few models generalize across multiple taxa, and thus are less useful for management scenarios that account for multiple target species. Using a dataset of 653 vertebrate roadkills collected from 2 parks in southern Ontario, we constructed generalized linear mixed models to determine the simultaneous risk factors for bird, frog, mammal, five-lined skink (Eumeces fasciatus), snake, toad, and turtle hatchling roadkills from among a set of 8 potential predictor variables. Posted road speed limit was the dominant roadkill predictor (positive coefficient), followed by maximum daily temperature (positive), habitat diversity (positive), and distance from wetlands (negative). All else being equal, as road speed limits increase from 20 km/hr to 50 km/hr, the model predicted the season's mean roadkill probability for a given location to increase from less than 0.1 to 0.75. Conversely, roadkill probability declined from 0.55 to 0.29 as distance from wetland edges increases from 0 km to 1 km. Model diagnostics calculated from randomly resampled cross-validation datasets indicated that the best model formulation had an averaged predictive accuracy of 67.5% and an area under the curve (AUC) of 0.867. The best model also reflected seasonal patterns of animal behavior, including late-summer frog movements and fall turtle hatching events. The best model also compared favorably to single-taxon equivalent models. To reduce the incidence of vertebrate roadkill, we recommend that managers lower road speed limits, especially on roads near diverse habitats and near wetlands, and on warmer days if temporary signage is used. © 2012 The Wildlife Society. 相似文献
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In Africa, no other nonhuman animal fulfils the role of ecosystem engineers to the extent of the elephant. However, little is known about the relationship between elephant modified habitats and species composition of other animals. Our objective was to sample the herpetofauna within an Acacia habitat that varied in the degree of elephant impact. If elephant foraging was only modifying but not degrading or enriching the habitat, then herpetofauna species abundance and richness were predicted to be similar in elephant damaged and elephant excluded areas. We conducted this study at Endarakwai Ranch in northeastern Tanzania for 6 months in 2007 and 2008. We sampled herpetofaunal species richness and abundance within high, medium and low elephant damaged areas and in a plot that excluded elephants. Areas of heavy damage yielded higher species richness than the exclusion plot. Species diversity did not differ between the damaged areas and the exclusion plot. Frogs were more abundant in areas of high damage; in contrast, toads were found the least in high damage areas. The results support the notion that free ranging elephants influence herpetofaunal species distribution by creating habitat complexity through modifying the woodland area. 相似文献
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Anthony R. Rendall John G. White Raylene Cooke Desley A. Whisson Thomas Schneider Lisa Beilharz Eleanor Poelsma Julia Ryeland Michael A. Weston 《Ecological Management & Restoration》2021,22(1):72-79
Autonomously triggered cameras are a common wildlife survey technique. The use of attractants and surrounding microhabitats is likely to influence detection probabilities and survey outcomes; however, few studies consider these factors. We compared three attractants (peanut butter‐based, tuna‐based and a control) in a Latin square design through a coastal shrubland with high microhabitat variability at Cape Otway, Victoria, Australia (38º50?S, 143º30?E). Deployments involved 36 cameras for four days in each of five years. The percentage cover of each vegetation structural type (low [no or sparse cover], moderate [grass] or high [shrubs]) within 20 m of each camera was calculated and reduced to a single variable using PCA. Dynamic occupancy modelling, with lure type and vegetation structure as covariates of detection probability, found that peanut butter attracted the greatest diversity of species (24 of 35 species, 69%) and yielded the greatest number of detections (50% of 319) when compared with tuna oil (66% and 24%, respectively) and the control (43% and 26%, respectively). Peanut butter attracted more Macropodidae (wallabies) and Muridae (rats and mice); however, vegetation structural variables were the greatest influence on Corvidae/Artamidae (raven/currawong) detections with higher detectability in more open areas. Vegetation structure also influenced Muridae detections. This study reinforces the critical choice of appropriate attractants and camera placement when investigating vertebrate groups and highlights the role of microhabitat in the detection of small mammals and birds. We suggest future large‐scale camera surveys consider different bait types and microhabitats in their designs, to control for any biases and enable future advice on ‘optimal’ methods. 相似文献
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2006年8月对高黎贡山自然保护区赧亢片区开展了鱼类、两栖和爬行动物的资源调查。调查结果,赧亢片区共有鱼类4种,隶属2目4科4属;两栖动物10种,隶属2目4科8属,其中云南特有种4种;爬行动物9种.隶属2目3科8属。赧亢片区的物种全为东洋界种,区系成分为西南、华南区,或者两区所共有的成分组成。将赧亢片区与邻近的高黎贡山自然保护区和小黑山省级自然保护区(小黑山片区)的多样性对比,赧亢片区不仅具有较高的物种多样性,亦是连接两个保护区物种交流和基因流动的重要通道。 相似文献