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1.
Arinaitwe, J., Byaruhanga, A. & Mafabi, P. 2000. Key sites for the conservation of waterbirds in Uganda. Ostrich 71 (1 &2): 102–105.

Uganda has a rich bird diversity with 1 008 species including 28 listed species (Collar et al. 1994) and 207 species of regional conservation concern (Bennun & Njoroge 1996). Over 240 species are waterfowl, of which nine are globally threatened, 45 are regionally threatened and five are considered to be of national conservation interest. This high waterbird diversity corresponds to a large wetland area covering about 10% of the land area of Uganda. However, only 6% of the wetlands fall under gazetted protected areas and only one site is recognised as of global importance under the terms of the Ramsar Convention. Three recent activities of JA, the National Wetlands Programme and East Africa Natural History Society (Uganda), have produced new information on distribution and abundance of waterbirds in Uganda. Concurrent with these activities, criteria for the identification of globally threatened species (Collar et al. 1994), species of regional conservation concern (Bennun & Njoroge 1996) and nationally important species (National Wetlands Programme, in press) have been developed. Also, criteria for selection of sites at the global (Ramsar and IBA), regional (IBA) and national (National Wetlands Programme) levels have become available. This paper reviews the advances in the knowledge of waterbirds in Uganda and applies the above criteria to highlight sites that are crucial for conservation at global, regional and national levels.  相似文献   

2.
Paul Mafabi 《Ostrich》2013,84(1-2):96-98
Mafabi, P. 2000. The role of wetland policies in the conservation of waterbirds: the case of Uganda. Ostrich 71 (1 & 2): 96–98.

Wetlands in Uganda provide important habitats for birds including several endemic species. With the ever increasing pressure to convert wetlands to agricultural lands, several species have lost their habitats, while others have become pests due to their opportunistic behaviour in modified habitats. The causes of wetland drainage and conversion in Uganda include population growth, economic reforms and a severe lack of information, legislation and inter-sectoral co-ordination. Community uses of wetlands have clear impacts on waterbirds. At Busolwe (case study 1) there is competition for land-use between Crowned Crane Balearica regulorum and man. Priority community uses of wetlands include fish-farming, agro-forestry and bee-keeping. There is a need for integrating bird conservation into overall wetland conservation objectives, especially with the aim of maintaining conditions suitable for waterbird survival during critical stages of the life-cycle. National wetland policies can play an important role in the conservation of waterbirds, as learned from Uganda's experiences. Recommendations for integrating bird conservation into the national wetland policy framework (as well as into national, district and local level planning processes) are made, which point to close co-operation between stakeholders for better management and on improved appreciation of wetlands values.  相似文献   

3.
Baltzer, M., Matthews, R., Howard, P., Kigenyi F. & Viskanic, P. 2000. Birds as biodiversity indicators in the planning of Forest Nature Reserves in Uganda. Ostrich 71 (1 & 2): 291.

In Uganda a policy decision has been taken to set aside 20% of the nation's 1.4 million hectare forest estate as Forest Nature Reserves, for the protection of biodiversity. The estate comprises 713 Forest Reserves, ranging in size from just a few hectares to well over 100 000 hectares, scattered all over the country. In order to select appropriate areas for designation as Nature Reserves, the Forest Department (with assistance from the European Community and Global Environmental Facility) has evaluated all the larger reserves for biodiversity, focusing on birds and four other biological indicator groups (woody plants, mammals, butterflies and moths). Building on earlier work, teams of departmental staff carried out detailed systematic biodiversity surveys of 65 major forests between May 1992 and March 1995. The work on birds involved 1 442 person-days of field observation and 1.2 million metre net-hours of mist-netting effort. Altogether 5 744 species-site records were made, involving 604 of Uganda's 1011 species: this brings the total number of species known from Uganda's forest reserves to 841 (83% of the country's birds). Several species not previously known from Uganda were recorded, especially in the north and east of the country where birds of the northern (Sudan/Guinea) savannas and Somali-Masai regions reach the extreme limits of their ranges. The bird data have been analysed alongside comparable data for the other four indicator taxa. Fortunately, areas of high species richness and levels of endemism for the five groups tend to coincide. Priority conservation sites have been identified and a national network of Forest Nature Reserves has been designed as part of a representative and efficient protected areas system for Uganda.  相似文献   

4.
Habitat loss and fragmentation caused by urbanization often have negative impacts on wildlife in cities. There are considerable studies investigating the relationship between species traits and fragmentation vulnerability. However, so far, very few studies have examined the influence of species traits combined with landscape factors on vulnerability to urbanization in urbanized landscapes. In this study, we investigated how species traits and park characteristics influenced bird sensitivity to urbanization in the highly urbanized city of Nanjing, China. We used the line-transect method to survey birds in 37 urban parks. For each bird species, we collected data on nine life-history and ecological traits that are commonly assumed to influence urbanization vulnerability. For each park, we selected six landscape variables that are commonly considered to influence bird response to urbanization. After phylogenetic correction, the nine species traits were used separately and in combination to evaluate their associations with species abundance, an indicator of urbanization vulnerability. We then used the RLQ and fourth-corner analyses to test relationships between species traits and environmental variables. We found that the 75 species analyzed demonstrated considerable variation in vulnerability to urbanization. Using PGLS analyses and model averaging, we found that habitat specificity was the single best ecological predictor of urbanization vulnerability in birds in Nanjing city parks. The RLQ analysis showed that body size and habitat specificity were correlated with distance to city center and connectivity of the parks, reflecting strong effects of trait-mediated environmental filters that selectively benefit species with smaller body mass and lower habitat specificity in urbanized landscape. Therefore, conservation efforts giving priority to species with high habitat specificity and to parks with high connectivity and far away from the city center may prove effective for the preservation of bird diversity in our highly urbanized system. Meanwhile, preventing future habitat loss and destruction in existing city parks may also effectively conserve these vulnerable species.  相似文献   

5.
Wildlife conservation in urban habitats is increasingly important due to current urbanization trends. We review the different approaches to studying birds in urban landscapes, and point out the importance of the habitat island ecological theory as a research framework for the management and conservation of urban birds. Based on two comprehensive research projects conducted at urban parks in Spain (Madrid) and Finland (Oulu and Rovaniemi), several different issues related to bird conservation in cities are discussed, main findings of these projects are presented, and future research needs are suggested. Urban parks are important biodiversity hotspots in cities. Fragmentation conditions have the same deleterious effects to urban birds as in other fragmented landscapes. Park size accounts for species accumulation in urban parks; this pattern being highly nested. Urban parks of 10–35 ha would contain most of the species recorded in cities, but other indicators related to the probabilities of persistence of the target species should be obtained. Wooded streets can increase urban landscape connectivity by providing alternative habitat for feeding and nesting during the breeding season. Because increasing the size of parks is difficult in cities, enhancement of habitat diversity and resource availability for birds within parks (e.g. nest boxes, winter feeding tables, etc.) appears to be a straightforward way of increasing urban bird diversity. However, human disturbance (pedestrians) should be controlled since it can negatively influence many urban birds. We present a conceptual model for urban bird conservation, which includes three aspects (management, environmental education and research) and new alternatives to promote the involvement of different sectors of the society.  相似文献   

6.
Biogeographical patterns of endemic terrestrial Afrotropical birds   总被引:3,自引:0,他引:3  
Biogeographical zones are described for terrestrial bird species endemic to the Afrotropics using up‐to‐date distributional data and multivariate statistical techniques. This provides an objective basis for a hierarchy of subregions, provinces and districts, based on a set of rules. Results are compared to previous studies at continental and regional scales. Biogeographical zones for passerines and non‐passerines are compared and found to be similar. Peaks of species richness and narrow endemism are described for the six major subdivisions (subregions) identified by the cluster analysis. Coincidence of peaks of species richness and narrow endemism is found to be low, such that areas selected to represent high species richness tallies will often fail to represent narrow endemics. Strong regionalization of Afrotropical birds indicates the need to use a biogeographical framework in conservation priority setting exercises to ensure that unique, but species‐poor, avifaunas are not neglected.  相似文献   

7.
Aim Existing climate envelope models give an indication of broad scale shifts in distribution, but do not specifically provide information on likely future population changes useful for conservation prioritization and planning. We demonstrate how these techniques can be developed to model likely future changes in absolute density and population size as a result of climate change. Location Great Britain. Methods Generalized linear models were used to model breeding densities of two northerly‐ and two southerly‐distributed bird species as a function of climate and land use. Models were built using count data from extensive national bird monitoring data and incorporated detectability to estimate absolute abundance. Projections of likely future changes in the distribution and abundance of these species were made by applying these models to projections of future climate change under two emissions scenarios. Results Models described current spatial variation in abundance for three of the four species and produced modelled current estimates of national populations that were similar to previously published estimates for all species. Climate change was projected to result in national population declines in the two northerly‐distributed species, with declines for Eurasian curlew Numenius arquata projected to be particularly severe. Conversely, the abundances of the two southerly distributed species were projected to increase nationally. Projected maps of future abundance may be used to identify priority areas for the future conservation of each species. Main conclusions The analytical methods provide a framework to make projections of impacts of climate change on species abundance, rather than simply projected range changes. Outputs may be summarized at any spatial scale, providing information to inform future conservation planning at national, regional and local scales. Results suggest that as a consequence of climate change, northerly distributed bird species in Great Britain are likely to become an increasingly high conservation priority within the UK.  相似文献   

8.
Synopsis We conducted an analysis of species associations using fish diversity and abundance surveys conducted in Bonaire Marine Park by recreational divers. We used data from the REEF (Reef Environmental Education Foundation) Fish Survey Project to compute Bray–Curtis similarity coefficients for all species pairs for the 100 most abundant species. We quantified relationships between species using hierarchical agglomerative clustering and non-metric multidimensional scaling (MDS) of the matrix of Bray–Curtis similarity coefficients. We identified three clusters of species from the analysis. MDS results showed species clusters occupied distinct regions across a continuous gradient of species in two-dimensional space, rather than form distinct clusters. While differences in habitat requirements can explain some of the pattern in pairwise species interactions, these results suggest that there are significant direct and indirect behavioral interactions mediating the distribution and abundance of species. Studies conducted to elucidate patterns of species-habitat relationships have been central to conservation planning for marine protected areas (MPAs). However, the role of behavioral interactions between species driving the dynamics of species composition within MPA networks, designed for representation of biological diversity, should be considered when selecting sites in order to be effective.  相似文献   

9.
Rapid urbanization in major cities has adversely affected avian biodiversity in both developed and developing countries. Due to over-urbanization and little regard for nature conservation, such cities are usually characterized by poor biodiversity. In contrast to central business district areas, suburbs may support greater levels of biodiversity through an increase in green areas. We examined urban bird species richness, abundance, and composition in Klang Valley, Peninsular Malaysia. We surveyed 141 points for passerines across 80 parks grouped into two different urban zones, namely central business districts and suburbs. Our results revealed that bird richness did not differ significantly (p = 0.994) between central business districts and the suburbs. We found that the abundances of birds were significantly greater in the suburbs than in central business districts. However, species composition was similar between the central business districts and suburbs. We also found that bird richness increased significantly with an increase in size of green areas and park areas, as well as the number of woody trees in both zones. Evidence from this study suggests that creating urban parks and gardens, coupled with tree planting in central business districts, is able to support greater biodiversity, at least for birds in cities similar to those found in the suburbs.  相似文献   

10.
Aim Chorological relationships describe the patterns of distributional overlap among species. In addition to revealing biogeographical structure, the resulting clusters of species with similar geographical distributions can serve as natural units in conservation planning. Here, we assess the extent to which temporal, methodological and taxonomical differences in the source of species’ distribution data can affect the relationships that are found. Location Western Europe. Methods We used two data sets – the Atlas of European mammals and polygon range maps from the IUCN Global Mammal Assessment – both as presence–absence data for UTM 50 km × 50 km squares. We performed pairwise comparisons among 156 species for each data set to build matrices of the similarity in distribution across species, using both Jaccard’s and Baroni‐Urbani & Buser’s indices. We then compared these similarity matrices (chorological relationships), as well as the species richness and occurrence patterns from the two data sets. Results As expected, range maps increased both the mean prevalence per species and mean species richness per grid cell in comparison to atlas data, reflecting the general view that these data types respectively over‐ and underestimate species occurrence. However, species richness and occurrence patterns in atlas and range map data were positively associated and, most importantly, the chorological relationships underlying the two data sets were highly similar. Main conclusions Despite many methodological, temporal and taxonomical differences between atlas data and range maps, the chorological relationships encountered between species were similar for both data sets. Chorological analyses can thus be robust to the data source used and provide a solid basis for analytical biogeographical studies, even over broad spatial scales.  相似文献   

11.
Anthropogenic noise is becoming more prevalent in the world and has been shown to affect many animal species, including birds. The impact of such noise was measured in Neotropical urban parks to assess how the noise affects avifauna diversity and species richness. We sampled bird species, and concurrently measured sound pressure (noise) levels (Leq, equivalent noise levels) in eight urban green areas or parks located in a large city (Belo Horizonte) in south‐eastern Brazil over a 1‐year period. The diversity of sampled points was measured by means of total species richness, Fisher's alpha and Shannon–Wiener diversity indices. Noise levels within all parks were greater than those in natural areas. We found that an increase in noise levels and the area of open habitats surrounding sampling points were negatively related to species richness. Social factors reflecting increased urbanization, such as higher incomes, were also negatively correlated with bird species richness. However, noise was the factor that explained most of the variance. These results suggest that anthropogenic noise can have a significant negative impact on the conservation value of urban parks for bird species.  相似文献   

12.
The role of land cover in bioclimatic models depends on spatial resolution   总被引:2,自引:0,他引:2  
Aim We explored the importance of climate and land cover in bird species distribution models on multiple spatial scales. In particular, we tested whether the integration of land cover data improves the performance of pure bioclimatic models. Location Finland, northern Europe. Methods The data of the bird atlas survey carried out in 1986–89 using a 10 × 10 km uniform grid system in Finland were employed in the analyses. Land cover and climatic variables were compiled using the same grid system. The dependent and explanatory variables were resampled to 20‐km, 40‐km and 80‐km resolutions. Generalized additive models (GAM) were constructed for each of the 88 land bird species studied in order to estimate the probability of occurrence as a function of (1) climate and (2) climate and land cover variables. Model accuracy was measured by a cross‐validation approach using the area under the curve (AUC) of a receiver operating characteristic (ROC) plot. Results In general, the accuracies of the 88 bird–climate models were good at all studied resolutions. However, the inclusion of land cover increased the performance of 79 and 78 of the 88 bioclimatic models at 10‐km and 20‐km resolutions, respectively. There was no significant improvement at the 40‐km resolution. In contrast to the finer resolutions, the inclusion of land cover variables decreased the modelling accuracy at 80km resolution. Main conclusions Our results suggest that the determinants of bird species distributions are hierarchically structured: climatic variables are large‐scale determinants, followed by land cover at finer resolutions. The majority of the land bird species in Finland are rather clearly correlated with climate, and bioclimate envelope models can provide useful tools for identifying the relationships between these species and the environment at resolutions ranging from 10 km to 80 km. However, the notable contribution of land cover to the accuracy of bioclimatic models at 10–20‐km resolutions indicates that the integration of climate and land cover information can improve our understanding and model predictions of biogeographical patterns under global change.  相似文献   

13.
The department of Antioquia, Colombia, lies in the northwestern corner of South America and provides a biogeographical link among divergent faunas, including Caribbean, Andean, Pacific and Amazonian. Information about the distribution of biodiversity in this area is of relevance for academic, practical and social purposes. This data paper describes the dataset containing all bird specimens deposited in the Colección de Ciencias Naturales del Museo Universitario de la Universidad de Antioquia (MUA). We curated all the information associated with the bird specimens, including the georeferences and taxonomy, and published the database through the Global Biodiversity Information Facility network. During this process we checked the species identification and existing georeferences and completed the information when possible. The collection holds 663 bird specimens collected between 1940 and 2011. Even though most specimens are from Antioquia (70%), the collection includes material from several other departments and one specimen from the United States. The collection holds specimens from three endemic and endangered species (Coeligena orina, Diglossa gloriossisima, and Hypopirrhus pyrohipogaster), and includes localities poorly represented in other collections. The information contained in the collection has been used for biodiversity modeling, conservation planning and management, and we expect to further facilitate these activities by making it publicly available.  相似文献   

14.
Evolutionary and genetic knowledge is increasingly being valued in conservation theory, but is rarely considered in conservation planning and policy. Here, we integrate phylogenetic diversity (PD) with spatial reserve prioritization to evaluate how well the existing reserve system in Victoria, Australia captures the evolutionary lineages of eucalypts, which dominate forest canopies across the state. Forty-three per cent of remaining native woody vegetation in Victoria is located in protected areas (mostly national parks) representing 48% of the extant PD found in the state. A modest expansion in protected areas of 5% (less than 1% of the state area) would increase protected PD by 33% over current levels. In a recent policy change, portions of the national parks were opened for development. These tourism development zones hold over half the PD found in national parks with some species and clades falling entirely outside of protected zones within the national parks. This approach of using PD in spatial prioritization could be extended to any clade or area that has spatial and phylogenetic data. Our results demonstrate the relevance of PD to regional conservation policy by highlighting that small but strategically located areas disproportionally impact the preservation of evolutionary lineages.  相似文献   

15.
Temporal and spatial environmental variability are predicted to have reddened spectra that reveal increases in variance with the period or length sampled. However, spectral analyses have seldom been performed on ecological data to determine whether these predictions hold true in the case of spatial environmental variability. For a 50 km long continuous transect of 128 point samples across a heterogeneous cultural landscape in the Czech Republic, both habitat composition and bird species composition decomposed by standard ordination techniques did indeed exhibit reddened spectra. The values of main ordination axes have relationships between log spectral density and log frequency with slopes close to -1, indicating 1/f, or 'pink' noise type of variability that is characterized by scale invariance. However, when habitat composition was controlled for and only residuals for bird species composition were analysed, the spectra revealed a peak at intermediate frequencies, indicating that population processes that structure bird communities but are not directly related to the structure of the environment might have some typical correlation length. Spatial variability of abundances of individual species was mostly reddened as well, but the degree was positively correlated to their total abundance and niche position (strength of species-habitat association). If 'pink' noise type of variability is as generally typical for spatial environmental variability as for temporal variability, the consequences may be profound for patterns of species diversity on different spatial scales, the form of species-area relationships and the distribution of abundances within species ranges.  相似文献   

16.
Aim To examine whether at a sub‐continental scale range‐limited species tend to occur close to areas of transition between vegetation boundaries more often than expected by chance. Location South Africa and Lesotho. Methods We examined the relationship between the distance of a grid square to ecological transition areas between vegetation types and both avian and frog range‐limited species richness in the quadrat. We used quadrats at a spatial resolution of quarter degree (15′ × 15′≈ 676 km2). Spatial congruence between areas representing range‐restricted species and those representing ecological transition zones was assessed using a random draw technique. Results Species richness and range size rarity are generally negatively correlated with distance to transition areas between vegetation communities when analysed for the whole region for both groups. Although this relationship becomes weaker after controlling for environmental energy and topographical heterogeneity, the explanatory power of distance to transition areas remains significant, and compared to the different biomes examined, accounts for most of the variation in bird richness (20%), frog richness (18%), range‐restricted bird species (17%) and range‐restricted frog species (16%) in the savanna biome. The random draw technique indicated that areas representing range‐restricted species were situated significantly closer in space to those areas representing transition areas between vegetation communities than expected by chance. Main conclusions We find that at the sub‐continental scale, when examined for South Africa, areas of transition between vegetation communities hold concentrations of range‐limited species in both birds and frogs. We find that South African endemic/range‐limited birds and frogs are located closer to ecological transition zones than endemics and non‐endemics combined. This has important implications for ongoing conservation planning in a biogeographical context.  相似文献   

17.
In Australian urban environments, revegetation and vegetation restoration are increasingly utilized conservation actions. Simple methods that help assess the utility of urban vegetation for bird species will help direct this effort for bird conservation purposes. We therefore examine whether ecological principles can be used to predict, a priori, the relative abundance of different bird species in urban vegetation. Our model proposes that a bird species will be in greater abundance where vegetation structure better reflects its foraging height requirements, and this relationship will be moderated by the landscape context of the patch. To quantify and test this model, we created an index to rank existing and revegetated urban vegetation sites in order of greatest expected abundance for each of 30 bird species. We tested this model, alongside two simpler models which consider landscape context and foraging height preferences alone, using bird abundance data from 20 woodland remnants and 20 revegetated sites in Brisbane, Australia. From these bird abundance data, we calculated the relative abundance of each species between the top‐ranking sites and lowest‐ranking sites. The model which incorporated both foraging height requirements and landscape context made predictions that were positively correlated with the data for 77% of species in remnant vegetation and 67% in revegetation. The results varied across species groups; for example, we achieved lower predictive success for canopy foraging species in the less mature revegetation sites. Overall, this model provided a reasonable level of predictive accuracy despite the diversity of factors which can influence species occurrence in urban landscapes. The model is generic and, subject to further testing, can be used to examine the effect of manipulating vegetation structure and landscape context on the abundance of different bird species in urban vegetation. This could provide a cost‐effective tool for directing urban restoration and revegetation efforts.  相似文献   

18.
随着城市化发展,许多公园鸟类栖息环境遭受破坏,导致当前的鸟类多样性与历史上的和周边的都存在较大差异,为此,我们从项目区域的当前-周边-历史三者间在鸟类物种及其栖息地上的落差分析入手,以此确定目标物种及其栖息地,并加以归类,从而有针对性地进行相关设计。2016年5月至2017年3月在湖南常德柳叶湖螺湾湿地公园开展的鸟类多样性提升设计中,通过实地调查并结合文献查阅,记录到项目区域16种,周边79种,历史上146种鸟类,运用三者间的物种落差分析法确定主要的21种可恢复目标物种和4种栖息地类型,结合项目区域及周边空间特点,将项目区域划分为4个区域,在各区域内设计并营建相应的栖息地,再配套采用多种鸟类招引措施。至2017年3月,项目区鸟类已可实地观察到39种,并于2017年12月吸引到超过2000只的野鸭群来此越冬。以上实际效果表明,设计有效地提升了湿地公园鸟类多样性且增加了景观要素,可充分发挥生物保护功能。  相似文献   

19.
Aim To describe species–area relationships in human settlements and compare them with those from a non‐urban habitat. Location West‐central Mexico. Methods We surveyed breeding birds in 13 human settlements and five shrubland patches. We estimated bird species richness using an abundance‐based coverage estimator with equal sample sizes to eliminate biases related to sampling effort differences. To assess species–area relationships, we performed log–log linear regressions between the size of the studied patches and their estimated bird richness. We also used a logarithmic approach to determine how the species–area relationship asymptoted and made use of the Michaelis–Menten model to identify the size at which the studied patches reached their maximum species richness. We also investigated (1) possible relationships among the estimated bird richness and other variables known to affect urban‐dwelling birds (built cover, plant species richness, tree cover or human population density) and (2) changes in bird community composition related to the size of the studied human settlements. Results Species–area relationships exhibited different patterns among the studied habitats. The log–log regression slope was steeper in human settlements, while the intercept was higher in shrublands. The maximum number of species was more than twofold higher in shrublands. Human settlement patch size was the only variable significantly related to bird richness. Our community composition results show that two main bird groups are related to human settlement size, and that as the size of human settlements increases, bird community similarity in relation to the largest city increases. Main conclusions Human settlements act as ecological islands, with pronounced species–area relationships. Our results suggest that an important threshold for bird species richness and community composition is reached in human settlements > 10.2 km2. This threshold is unlikely to be generalizable among bio‐regions, and thus should be quantified and considered when studying, managing and/or planning urban systems.  相似文献   

20.
Insular biogeography of mammals in Canadian parks: a re-analysis   总被引:1,自引:0,他引:1  
Aim Glenn & Nudds (1989) compared mammal species richness in Canadian parks to estimated species-area relationships prior to European settlement to test if parks presently contain their historical compliment of species. However, the data they used to estimate the presettlement species-area relationships were not commensurate with the scale of the parks and were not independent. This uncertainty reduces the utility of Glenn and Nudds analysis to detect which, if any, parks are experiencing mammal extirpations and ultimately to direct conservation efforts to enhance mammal conservation in Canada. We improved Glenn and Nudds methods and re-assesed the conservation status of mammals in Canadian parks. Location Canada. Methods We constructed species-area curves for disturbance tolerant and intolerant species in five mammal regions of Canada by sampling historical range maps using plots of 10– 10,000 km2. We compared these estimates of expected species richness to current species richness in thirty-six parks and contrast our results with those of Glenn and Nudds. Results All ten re-estimated species-area regressions had higher intercepts than those reported by Glenn and Nudds; four had lower slopes. Of seventy-two cases analysed, we found twenty in which parks had fewer species than expected and four in which parks had more species than expected, compared to fourteen and thirty-three, respectively, reported by Glenn and Nudds. Changes in both the regression parameters and increases in the prediction intervals accounted for the disparity between these results. Park residuals were not significantly different from zero in eight of ten analyses. Residuals for parks in the Alleghenian-Illinoian mammal province were negative and decreased with increasing park size. Main conclusions Improvement of Glenn and Nudds methods had an effect on both the parameter estimates and precison of the presettlement species-area curves. As a result, mammal conservation in some Canadian parks is worse than Glenn and Nudds reported. Six additional parks contained fewer disturbance intolerant species than predicted. However, Glenn and Nudds finding of systematic differences between expected and observed species richness in parks in the densely populated region of southern Ontario, southern Quebec and the maritime provinces was not an artefact of their methods. In this region, seven of ten parks appear to have lost disturbance-sensitive species of mammals. The pattern of species loss in this region was consistent with the idea that these parks have become isolated from mammal dispersal by surrounding habitat change and have experienced local species extirpations.  相似文献   

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