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Species richness, species range size and ecological specialisation among African primates: geographical patterns and conservation implications 总被引:5,自引:0,他引:5
The geographical distribution of species richness and species range size of African anthropoid primates (catarrhines) is investigated and related to patterns of habitat and dietary niche breadth. Catarrhine species richness is concentrated in the equatorial regions of central and west Africa; areas that are also characterised by low average species range sizes and increased ecological specificity. Species richness declines with increasing latitude north and south of the equator, while average species range size, habitat and dietary breadth increase. Relationships between species richness, species range size and niche breadth remain once latitudinal and longitudinal effects have been removed. Among areas of lowest species richness, however, there is increased variation in terms of average species range size and niche breadth, and two trends are identified. While most such areas are occupied by a few wide-ranging generalists, others are occupied by range-restricted specialist species. That conservation efforts increasingly focus on regions of high species richness may be appropriate if these regions are also characterised by species that are more restricted in both their range size and their ecological versatility, although special consideration may be required for some areas of low species richness. 相似文献
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We have isolated and characterized 18 microsatellite loci in the Peking duck (Anas platyrhynchos). The average number of alleles per locus was 3.5, ranging from one to six in domestic Peking ducks (n = 40). All of the markers were polymorphic in a sample of five mallards (A. platyrhynchos; two to eight alleles). Seventeen of the 18 markers amplified in Muscovy ducks (Cairina moschata) with 11 being polymorphic in our sample (n = 14). Amplification of the markers in different species comprising the subfamilies Anatinae and Anserinae indicates their potential value for population genetic applications in a wide range of waterfowl species. 相似文献
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Hybridisation is the interbreeding of genetically distinct groups that can lead to introgression – an exchange of genetic material between species. Hybridisation is of conservation concern when an alien invasive species is involved, as it can lead to a loss of local genetic adaptations and genetic diversity. Hybridisation is a significant threat for many dabbling ducks where interbreeding with the closely related invasive Mallard Anas platyrhynchos is extremely common. Phenotypic evidence suggests that Mallard populations in South Africa hybridise with the indigenous Yellow-billed Duck Anas undulata. The aim of this study was to determine the incidence of hybridisation between Yellow-billed Ducks, occurring in central and northwestern South Africa, and introduced Mallards. Genetic variation between Mallards, Yellow-billed Ducks, and their inferred hybrids was assessed using mitochondrial and microsatellite DNA markers. All samples inferred to be hybrids based on the phenotype were found to have Yellowbilled Duck mitochondrial DNA and showed minimal evidence of admixture across the microsatellite markers. Thus, these results do not support the notion that hybridisation between Mallards and Yellow-billed Ducks is prevalent in central and northwestern South Africa. However, hybridisation could be occurring where Mallards are found in higher abundance, such as in the Western Cape Province. Therefore, continued monitoring of this potential hybridisation should be performed frequently and throughout South Africa. 相似文献
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Beth Mackay Rob M. Little Arjun Amar Phil A. R. Hockey 《The Journal of wildlife management》2014,78(4):671-678
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Johannes Hausharter Sonia Rashid Johannes Wessely Patrick Strutzenberger Dietmar Moser Andreas Gattringer Konrad Fiedler Karl Hülber Stefan Dullinger 《Global Ecology and Biogeography》2023,32(9):1535-1548
Aim
The breadth of ecological niches and dispersal abilities have long been discussed as important determinants of species' range sizes. However, studies directly comparing the relative effects of both factors are rare, taxonomically biased and revealed inconsistent results.Location
Europe.Time Period
Cenozoic.Major Taxa
Butterflies, Lepidoptera.Methods
We relate climate, diet and habitat niche breadth and two indicators of dispersal ability, wingspan and a dispersal tendency index, to the global range size of 369 European-centred butterfly species. The relative effects of these five predictors and their variation across the butterfly phylogeny were assessed by means of phylogenetic generalized least squares models and phylogenetically weighted regressions respectively.Results
Climate niche breadth was the most important single predictor, followed by habitat and diet niche breadth, while dispersal tendency and wingspan showed no relation to species' range size. All predictors together explained 59% of the variation in butterfly range size. However, the effects of each predictor varied considerably across families and genera.Main Conclusions
Range sizes of European-centred butterflies are strongly correlated with ecological niche breadth but apparently independent of dispersal ability. The magnitude of range size–niche breadth relationships is not stationary across the phylogeny and is often negatively correlated across the different dimensions of the ecological niche. This variation limits the generalizability of range size–trait relationships across broad taxonomic groups. 相似文献8.
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Robert M. Inman Mark L. Packila Kristine H. Inman Anthony J. Mccue Gary C. White Jens Persson Bryan C. Aber Mark L. Orme Kurt L. Alt Steven L. Cain Jay A. Fredrick Bob J. Oakleaf Shawn S. Sartorius 《The Journal of wildlife management》2012,76(4):778-792
Wolverines (Gulo gulo) in the conterminous United States have experienced range contraction, are uncommon, and have been designated as warranted for protection under the United States Endangered Species Act. Data from the southern edge of the wolverine's circumpolar distribution is sparse, and development of effective conservation strategies would benefit from a more complete understanding of the species' ecology. We captured and radio-monitored 30 wolverines in the Greater Yellowstone Ecosystem (GYE), tested for seasonal habitat selection by elevation band, and examined a suite of spatial characteristics to clarify our understanding of the wolverine's niche. Wolverines in GYE selected for areas >2,600 m latitude-adjusted elevation (LAE; n = 2,257 wolverine locations [12 F, 6 M]). Wolverines avoided areas <2,150 m LAE, including during winter when the vast majority of ungulates are pushed to these elevations by deep snow. Wolverine home ranges were large relative to body size, averaging 303 km2 for adult females and 797 km2 for adult males (n = 13 [8 F, 5 M] and 33 wolverine-years). Resident adults fit with Global Positioning System (GPS) collars used an area >75% the size of their multi-year home range in an average of 32 days (n = 7 [5 F, 2 M]). Average movement rates of 1.3 km/2-hr indicated that both sexes move distances equivalent to the diameter of their home range every 2 days or the circumference of their home range in <1 week (n = 1,329 2-hr movements, n = 12 individuals [7 F, 5 M]). This capability for movement, the short time-frame over which home ranges were developed, and a lack of home range overlap by same sex adults ( , 90% CI = 0.0–4.8%, n = 22 pairs) suggested territoriality. We estimated wolverine density to be 3.5/1,000 km2 of area >2,150 m LAE (95% CI = 2.8–9.6). Dispersal movements extended to at least 170 km for both sexes (n = 5 F, 2 M). At the southern edge of distribution, where suitable and unsuitable conditions exist in close proximity, wolverines selected high-elevation areas near alpine tree-line where a mix of forest, meadow, and boulder fields were present, deep snow-cover existed during winter, and low temperatures near freezing can occur throughout the year. Persistence in these areas where the growing season is brief requires large home ranges that are regularly patrolled, a social system that provides exclusive access to resources, and low densities. These characteristics, along with low reproductive rates, are prevalent throughout the species range, indicating that wolverines are specialists at exploiting a cold, unproductive niche where interspecific competition is limited. The vulnerability inherent in occupying this unproductive niche was likely influential in previous declines within the conterminous United States and will remain a factor as wolverines encounter modern human influences. Conserving wolverines in the conterminous United States will require collaborative management over a large geographic scale. © 2011 The Wildlife Society. 相似文献
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Juliane Struve Kai Lorenzen Julia Blanchard Luca B?rger Nils Bunnefeld Charles Edwards Joaquín Hortal Alec MacCall Jason Matthiopoulos Bram Van Moorter Arpat Ozgul Fran?ois Royer Navinder Singh Chris Yesson Rodolphe Bernard 《Biology letters》2010,6(5):575-578
The workshop ‘Spatial models in animal ecology, management and conservation’ held at Silwood Park (UK), 9–11 March 2010, aimed to synthesize recent progress in modelling the spatial dynamics of individuals, populations and species ranges and to provide directions for research. It brought together marine and terrestrial researchers working on spatial models at different levels of organization, using empirical as well as theory-driven approaches. Different approaches, temporal and spatial scales, and practical constraints predominate at different levels of organization and in different environments. However, there are theoretical concepts and specific methods that can fruitfully be transferred across levels and systems, including: habitat suitability characterization, movement rules, and ways of estimating uncertainty. 相似文献
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Alex Atkins Stephen M. Redpath Rob M. Little Arjun Amar 《The Journal of wildlife management》2017,81(4):610-616
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The abundant centre hypothesis (ACH) assumes that population abundance, population size, density and per‐capita reproductive output should peak at the centre of a species' geographic range and decline towards the periphery. Increased isolation among and decreased reproductive output within edge populations should reduce within‐population genetic diversity and increase genetic differentiation among edge relative to central populations. The ACH also predicts asymmetrical gene flow, with net movement of migrants from the centre to edges. We evaluated these ecological assumptions and population‐genetic predictions in the endemic flowering plant Leavenworthia stylosa. Although populations were more spatially isolated near range edges, the geographic centre was surrounded by and not coincident with areas of peak population abundance, and plant density increased towards range edges. Per‐capita seed number was not associated with distance to the range centre, but seed number/m2 increased near range edges. In support of ACH predictions, allelic diversity at 12 microsatellite loci declined with distance from the range centre, and pairwise FST values were higher between edge populations than between central populations. Coalescent analyses confirmed that gene flow was most infrequent between edge populations, but there was not an asymmetric pattern of gene flow predicted by the ACH. This study shows that among‐population demographic variability largely did not support the ACH, while patterns of genetic diversity, differentiation and gene flow were generally consistent with its predictions. Such mixed support has frequently been observed in tests of the ACH and raises concerns regarding the generality of this hypothesis for species range limits. 相似文献
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《Ostrich》2013,84(1):85-87
The number of Egyptian Geese Alopochen aegyptiaca has increased in the Western Cape province, South Africa, during the past few decades and they are allegedly perceived as a problem on golf courses. However, attitudes towards the geese on golf courses in the province have not been empirically assessed. We surveyed the residents and members of the Steenberg Golf Estate, Cape Town, during April 2012 to evaluate perceptions towards Egyptian Geese on the estate. A standardised, anonymous questionnaire was sent to 548 estate residents and non-resident golfing members. Of the 112 respondents, the majority (92, or 84%) considered that geese are a problem on the estate. The ranking of the perceived problem was: 16 (15%) minimal problem, 34 (33%) moderate problem and 54 (52%) severe problem. The majority also considered that the goose population should be reduced by 50% or more (90, or 86% of all respondents). Dealing with Egyptian Geese numbers and activities on golf courses is complex. The option of designing golf courses and adjacent vegetation so that they are attractive to local bird species, while simultaneously being less attractive to Egyptian Geese, is available. 相似文献
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Craig R. McClain Sarah Mincks Hardy 《Proceedings. Biological sciences / The Royal Society》2010,277(1700):3533-3546
Anthropogenic disturbances such as fishing, mining, oil drilling, bioprospecting, warming, and acidification in the deep sea are increasing, yet generalities about deep-sea biogeography remain elusive. Owing to the lack of perceived environmental variability and geographical barriers, ranges of deep-sea species were traditionally assumed to be exceedingly large. In contrast, seamount and chemosynthetic habitats with reported high endemicity challenge the broad applicability of a single biogeographic paradigm for the deep sea. New research benefiting from higher resolution sampling, molecular methods and public databases can now more rigorously examine dispersal distances and species ranges on the vast ocean floor. Here, we explore the major outstanding questions in deep-sea biogeography. Based on current evidence, many taxa appear broadly distributed across the deep sea, a pattern replicated in both the abyssal plains and specialized environments such as hydrothermal vents. Cold waters may slow larval metabolism and development augmenting the great intrinsic ability for dispersal among many deep-sea species. Currents, environmental shifts, and topography can prove to be dispersal barriers but are often semipermeable. Evidence of historical events such as points of faunal origin and climatic fluctuations are also evident in contemporary biogeographic ranges. Continued synthetic analysis, database construction, theoretical advancement and field sampling will be required to further refine hypotheses regarding deep-sea biogeography. 相似文献
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Sarah J. Ivory James Russell Regan Early Dov F. Sax 《Global Ecology and Biogeography》2019,28(7):992-1003
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Abstract.
- 1 Species rarity is a common phenomenon in the biological world. Although rare species have always interested biologists, the meaning of ‘rare’ has not always been clear with the definition of rarity often arbitrary.
- 2 In the current study, we investigate rarity in stream ecosystems using black flies (Diptera: Simuliidae). We defined rare species a priori as those species found ≤ 10% of stream sites examined (n = 111 streams for ‘summer collections’; n = 88 collection for ‘spring’ collections). Hence, we are exploring only one axis of rarity, restricted range.
- 3 We first consider the distribution of each rare species separately to determine if the mean (euclidian) distance among streams (habitats) for each rare species differs from a random model. We next took a collective approach by pooling all rare species to determine the influence of stream conditions, niche breadth, and distance among habitats on rarity.
- 4 Even within this biologically uniform group of flies, dispersal, range limits, and stream conditions all might play a role in rarity, and the importance of each of these factors appear to vary among species. Rather than looking for broad causes of rarity, future studies might be more fruitful if they looked at species‐specific causes.
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Tarek Hattab Carol X. Garzón‐López Michael Ewald Sandra Skowronek Raf Aerts Hélène Horen Boris Brasseur Emilie Gallet‐Moron Fabien Spicher Guillaume Decocq Hannes Feilhauer Olivier Honnay Pieter Kempeneers Sebastian Schmidtlein Ben Somers Ruben Van De Kerchove Duccio Rocchini Jonathan Lenoir 《Diversity & distributions》2017,23(7):806-819
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Patrick T. Rohner Gerhard Bchli Lucia Pollini Paltrinieri Peter Duelli Martin K. Obrist Ralf Jochmann Wolf U. Blanckenhorn 《Insect Conservation and Diversity》2015,8(4):367-376
- Elevational gradients influence the distribution and abundance of species drastically and can lead to variation in community composition. Although coprophagous flies are of ecological and economic importance, their biodiversity and distribution are largely neglected. We studied the impact of steep elevational gradients and geography on the distribution of sepsid flies in the Swiss Alps.
- Sepsidae are a family of acalyptrate flies strongly associated with decaying organic matter and vertebrate dung, and characterised by a high extent of sympatry in their breeding substrates. Historical, haphazardly sampled specimens from 116 locations covering an elevational range from 200 to 2000 m were available in ethanol collections of various Swiss museums.
- Nineteen species encompassing all native genera (Meroplius, Nemopoda, Saltella, Sepsis and Themira) were recorded. Local species richness increased linearly with elevation, while area‐corrected regional species richness of elevational belts increased asymptotically. Species occurring at higher altitudes had lower wing loadings and greater elevational ranges than lowland species, supporting Rapoport's elevational rule.
- Despite compositional similarities, the sepsid communities of the northern lowlands differed significantly from the alpine sepsid fauna. The southern lowlands were particularly differentiated in community composition due to a number of presumably thermophilic species that predominantly occur south of the Alps.
- Relative abundances of several species were thus strongly affected by elevation and climatic variables. We illustrate the impact of elevational gradients and geography on a community of closely related, often sympatric species, and discuss potential mechanisms of niche partitioning via temporal succession, thermal adaptation and differential resource use.