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1.
Rebecca Mcguire Christopher Latty Stephen Brown Shiloh Schulte Sarah Hoepfner Samuel Vassallo Paul Smith 《Ibis》2022,164(1):329-335
Cameras are important tools used to determine nest fate, identify predators and evaluate behaviour; however, they may impact the parameters they are used to measure, thereby biasing results. We evaluated the impact of cameras ? 10 m from the nest on shorebird nest survival at the Canning River Delta, Alaska, 2017–2018 (ncontrol = 122, ncamera = 109) using a much larger sample size than in previous studies conducted in the Arctic and random assignments at nest discovery. We found no effect of camera presence at the nest on daily nest survival (model-averaged daily survival rate (DSR) 85% confidence interval (CI); control: 0.971–0.983, camera: 0.969–0.982). We suggest that nest survival studies of tundra-nesting birds should consider the use of cameras to minimize researcher disturbance, increase the accuracy of fate assignments, and broaden the ecological data collected (e.g. incubation behaviour, predator identification and non-anthropogenic non-predation disruption such as by caribou). 相似文献
2.
Species conservation requires an understanding of the factors and interactions affecting species distribution and behavior, habitat availability and use, and corresponding vital rates at multiple temporal and spatial scales. Opportunities to investigate these relationships across broad geographic regions are rare. We combined long-term waterfowl population surveys, and studies of habitat use and breeding success, to develop models that identify and incorporate these interactions for upland-nesting waterfowl in the Prairie Pothole Region (PPR) of Canada. Specifically, we used data from the annual Waterfowl Breeding Population and Habitat Survey (1961–2009) at the survey segment level and associated habitat covariates to model and map the long-term average duck density across the Canadian PPR. We analyzed nest location and fate data from approximately 25,000 duck nests found during 3 multi-year nesting studies (1994–2011) to model factors associated with nest survival and habitat selection through the nesting season for the 5 most common upland nesting duck species: mallard (Anas platyrhynchos), gadwall (Mareca strepera), blue-winged teal (Spatula discors), northern shoveler (Spatula clypeata), and northern pintail (Anas acuta). Duck density was highly variable across the Canadian PPR, reflecting positive responses to local wetland area and count, and amounts of cropland and grassland, a regional positive response to latitude, and a negative response to local amounts of tree cover. Nest survival was affected by temporal and spatial variables at multiple scales. Specifically, nest survival demonstrated interactive effects among species, nest initiation date, and nesting cover type and was influenced by relative annual wetness, population density, and surrounding landscape composition at landscape scales, and broad geographic gradients (east-west and north-south). Likewise, species-specific probability of nest habitat selection was influenced by timing of nest initiation, population density, relative annual wetness, herbaceous cover, and tree cover in the surrounding landscape, and location within the Canadian PPR. We combined these models, with estimates of breeding effort (nesting, renesting, and nest attempts) from existing literature, in a stochastic conservation planning model that estimates nest distribution and success given spatiotemporal variation in duck density, habitat availability, and influential covariates. We demonstrate the use of this model by examining various conservation planning scenarios. These models allow estimation of local, landscape, and regional influence of conservation investments and other landscape changes on the productivity of breeding duck populations across the PPR of Canada. These models lay the groundwork for the incorporation of conservation delivery costs for full return-on-investment analyses and scenario analyses of climate, habitat, and land use change in regional and continental population models. 相似文献
3.
Determinants of successful establishment and post‐translocation dispersal of a new population of the critically endangered St. Croix ground lizard (Ameiva polops)
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Lee A. Fitzgerald Michael L. Treglia Nicole Angeli Toby J. Hibbitts Daniel J. Leavitt Amanda L. Subalusky Ian Lundgren Zandy Hillis‐Starr 《Restoration Ecology》2015,23(6):776-786
Translocation to areas free of exotic predators, habitat degradation, or disease may be the most viable restoration option for many endangered species. We report on a successful translocation of the critically endangered St. Croix ground lizard, Ameiva polops, extirpated from St. Croix, U.S. Virgin Islands, Caribbean, by predation from introduced mongooses (Herpestes auropunctatus). We translocated 57 adult A. polops from Green Cay to Buck Island in May 2008. We placed 4 females and 3 males each in eight, 100 m2, enclosures on Buck Island for 71 days, then the enclosures were opened. During the enclosure period, 20 individuals were identified and 32 others were seen. The average number sighted per survey was only 5.28 (range = 2–10). One hatchling was sighted in an enclosure, indicating a translocated female successfully nested. Body condition of the translocated individuals increased significantly by the end of the enclosure period. Population monitoring surveys at 61 sites across Buck Island showed that 5 years after the initial translocation in June 2013, the new population had grown to an estimated 1,473 individuals and occupied 58.9% of the island. We attribute eradication of mongoose, life history of the species, large propagule size, condition of habitat, soft‐release, use of adults, interagency collaboration, and systematic assessment as primary factors that facilitated this successful translocation. Our findings provide meaningful insights on factors that enhance the potential for successful translocations, and point to new strategies aimed at restoring populations of endangered reptiles in their native ranges. 相似文献
4.
Rosa rugosa Thunb. is one of the dominant and important shrub species in estuary dunes and shingle beaches of northern China. However, its area of distribution, the number of populations, and the size of each population have decreased rapidly in the past two decades because of habitat degradation and loss. Random amplified polymorphic DNA markers were used to determine the genetic diversity of four remaining large natural populations of R. rugosa and to discuss an effective conservation strategy for this endangered species in China. High genetic variations were detected in R. rugosa populations in China. The mean percentage of polymorphic loci (P%) within four local populations was 57.99%, with the P% of the total population being 75.30%. Mean Shannon's information index (H0) was 0.2826, whereas total Ho was 0.3513. The genetic differentiation among populations was 0.1878, which indicates that most genetic diversity occurs within populations. Population Tumenjiang (TMJ) showed the highest genetic diversity (P% = 66.27%; H0 = 0.3117) and contained two exclusive bands. Population Changshandao (CSD) showed higher genetic diversity (P% =59.04%; H0 = 0.3065). Populations TMJ and CSD contained 95.33% and 99.33%, respectively, of loci with moderate to high frequency (P〉0.05) of the total population. These results indicate that populations TMJ and CSD should be given priority for in situ conservation and regarded as seed or propagule sources for ex situ conservation. The results of the present study also suggest that R. rugosa in China has become endangered as a result of human actions rather than genetic depression of populations; thus, human interference should be absolutely forbidden in R. rugosa habitats. 相似文献
5.
A previous study with amplified fragment length polymorphism (AFLP) fingerprints found no evidence of genetic impoverishment in the endangered Centaurea borjae and recommended that four management units (MUs) should be designated. Nevertheless, the high ploidy (6x) of this narrow endemic plant suggested that these conclusions should be validated by independent evidence derived from non-nuclear markers. Here, the variable trnT-F region of the plastid genome was sequenced to obtain this new evidence and to provide an historical background for the current genetic structure. Plastid sequences revealed little genetic variation; calling into question the previous conclusion that C. borjae does not undergo genetic impoverishment. By contrast, the conclusion that gene flow must be low was reinforced by the strong genetic differentiation detected among populations using plastid sequences (global FST = 0.419). The spatial arrangement of haplotypes and diversity indicate that the populations currently located at the center of the species range are probable sites of long-persistence whereas the remaining sites may have derived from a latter colonization. From a conservation perspective, four populations contributed most to the allelic richness of the plastid genome of the species and should be given priority. Combined with previous AFLP results, these new data recommended that five, instead of four, MUs should be established. Altogether, our study highlights the benefits of combining markers with different modes of inheritance to design accurate conservation guidelines and to obtain clues on the evolutionary processes behind the present-day genetic structures. 相似文献
6.
Ania Pinares Jorge Gonzlez-Astorga Andrew P. Vovides Julio Lazcano Wagner A. Vendrame 《Biochemical Systematics and Ecology》2009,37(4):385-394
The diversity and genetic structure of seven populations of Microcycas calocoma (Miq.) A. DC, were analyzed by gel electrophoresis using 19 allozymes. The mean number of alleles per locus (A) was 1.49 and the percentage of polymorphic loci was relatively high (P = 48.09). The mean observed (Ho) and expected heterozygosity (He) were 0.20 and 0.17, respectively. The F-statistics revealed a high population structure (Fst = 0.34). Mean gene flow between population pairs was Nm = 0.96. Results were compared with those of other cycad species, and indicate that M. calocoma populations have become fragmented due to increasing pressures of habitat conversion and disturbance. Also, geographical isolation among populations has generated allele loss in relation to altitude. The establishment and maintenance of protected areas for in situ conservation is critical to preserve the high genetic diversity of M. calocoma. Conservation strategy guidelines have been specified. 相似文献
7.
Murtaugh PA 《Ecology letters》2008,11(9):E6-E8
Douglass et al. ( Ecol. Lett. , 11 , 2008, 1) concluded that grazer diversity and predator diversity have an interactive effect on herbivore abundance in experimental marine mesocosms. Re-analysis of their data fails to support this conclusion, which was apparently based on a statistical miscalculation. 相似文献
8.
This EFOMP Policy Statement is an amalgamation and an update of the EFOMP Policy Statements No. 2, 4 and 7. It presents guidelines for the roles, responsibilities and status of the medical physicist together with recommended minimum staffing levels. These recommendations take into account the ever-increasing demands for competence, patient safety, specialisation and cost effectiveness of modern healthcare services, the requirements of the European Union Council Directive 2013/59/Euratom laying down the basic safety standards for protection against the dangers arising from exposure to ionising radiation, the European Commission’s Radiation Protection Report No. 174: “Guidelines on medical physics expert”, as well as the relevant publications of the International Atomic Energy Agency. The provided recommendations on minimum staffing levels are in very good agreement with those provided by both the European Commission and the International Atomic Energy Agency. 相似文献
9.
Managing for naturalness alone is not an effective way to preserve all the valuable natural features of the Białowieża Forest – a reply to Jaroszewicz et al.
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Bogdan Brzeziecki Stanisław Drozdowski Henryk Żybura Leszek Bolibok Kamil Bielak Jacek Zajączkowski 《植被学杂志》2017,28(1):223-231
Currently, Brzeziecki et al. 2016 (Journal of Vegetation Science 27: 460–467.) are using data from permanent study plots established in 1936 in Bia?owie?a National Park (NE Poland) to develop theoretical equilibrium tree size distributions and to then compare modelled and actual distributions with a view to assessing the population dynamics of the species involved. As part of their discussion, the authors address the question of possible consequences for the overall diversity of forest ecosystems under strict protection if long‐term trends relating to tree population densities and size structures are maintained. In the overall context of the above, the goal of the present paper is to respond to Jaroszewicz et al. (Journal of Vegetation Science 28: 218–222.) who suggest that the paper of Brzeziecki et al. (2016) is not representative for the whole Bia?owie?a National Park, and that – in this connection – strict protection should not be seen as a cause for concern. In this paper, we show that the data analysed by Brzeziecki et al. (2016) adequately characterize conditions in the wider Park. We also point out that the thorough scientific understanding of the long‐term dynamics of woodland communities under strict protection should indeed be taken into account as efforts are made to arrive at an effective conservation strategy capable of ensuring that the uniquely valuable features of the Bia?owie?a Forest are retained. 相似文献