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1.
Proactive conservation planning for species requires the identification of important spatial attributes across ecologically relevant scales in a model-based framework. However, it is often difficult to develop predictive models, as the explanatory data required for model development across regional management scales is rarely available. Golden eagles are a large-ranging predator of conservation concern in the United States that may be negatively affected by wind energy development. Thus, identifying landscapes least likely to pose conflict between eagles and wind development via shared space prior to development will be critical for conserving populations in the face of imposing development. We used publically available data on golden eagle nests to generate predictive models of golden eagle nesting sites in Wyoming, USA, using a suite of environmental and anthropogenic variables. By overlaying predictive models of golden eagle nesting habitat with wind energy resource maps, we highlight areas of potential conflict among eagle nesting habitat and wind development. However, our results suggest that wind potential and the relative probability of golden eagle nesting are not necessarily spatially correlated. Indeed, the majority of our sample frame includes areas with disparate predictions between suitable nesting habitat and potential for developing wind energy resources. Map predictions cannot replace on-the-ground monitoring for potential risk of wind turbines on wildlife populations, though they provide industry and managers a useful framework to first assess potential development. 相似文献
2.
We evaluate the areas with potential negative impacts in a golden eagle population derived of the development of wind farms.
At present, the entire golden eagle Galician population (5–6 pairs) is located within an area of about 2,000 km2. Grid squares of 10 × 10 km UTM in the province were scored for current and future wind turbine density and probability of
occurrence of golden eagle. This probability was obtained using cartographic models of habitat selection for two different
historic periods. Potential risk index (PRI) was calculated for each grid square by multiplying the wind turbine density score
by the probability of occurrence score. With the PRIs obtained a cartographic model of potential impact of wind farms on the
golden eagle population was constructed. No significant correlation was observed between current wind turbine density and
the probability of occurrence of golden eagle. A significant positive correlation was observed between current and future
wind turbine density and the probability of occurrence of golden eagle. The areas with highest potential risk are eastern
and the central mountains of Ourense where the species breeds. The risk model presented could be applied to future wind farm
proposals and monitor potential interactions of golden eagles with wind farms in the Province of Ourense. 相似文献
3.
Demography and habitat availability in territorial occupancy of two competing species 总被引:3,自引:0,他引:3
Although metapopulation dynamics have become the focus of considerable theoretical research, little attention has been paid to its role when examining the coexistence of species. When two or more species live in the same patch network, interspecific interactions may affect their dispersal, colonization and extinction rates, and it may be possible to incorporate competition affecting these parameters in metapopulation models. Here, we extend the territorial occupancy model proposed by Lande to competing species. Our model estimates an equilibrium proportion of habitat occupancy as a function of life‐history parameters, dispersal behavior, habitat suitability and interspecific interactions. Moreover, it could prove to be useful as a tool in the assessment of potential management decisions. We apply the model to the golden Aquila chrysaetos and the Bonelli's eagle Hieraaetus fasciatus, two territorial raptors that coexist in the Mediterranean region, sharing food and nesting habitats. Over the last twenty years, while the golden eagle has maintained and, in some cases, increased its breeding numbers, Bonelli's eagle has suffered a marked decline, with many territories abandoned by the latter now occupied by the former. This suggests that the dynamics of these species could be influenced by interspecific competition. The model identified the relative importance of competition (stable equilibrium that allows long‐term coexistence) and predicted that, when habitat overlap is slight as in the study area, intraspecific dynamics are much more important for the persistence of each species than interspecific ones. Our results suggest that the improvement of territorial bird survival and productivity are the most urgently needed actions to be undertaken in the case of the golden eagle, while for Bonelli's eagle efforts should be focused on improving territorial and non‐territorial bird survival. As habitat conservation measures, the proportion of suitable exclusive habitat should be increased for both species. 相似文献
4.
Pascual López-López Clara García-Ripollés José Miguel Aguilar Francisco Garcia-López José Verdejo 《Journal of Ornithology》2006,147(1):97-106
Predictive models on breeding habitat preferences of Bonelli’s eagle (Hieraaetus fasciatus; Aves: Accipitridae) have been performed at four different spatial scales in Castellón province, East of Iberian Peninsula.
The scales considered were: (1) nest site scale (1×1 km2 Universal Transverse Mercator (UTM) square containing the nest); (2) near nest environment (3×3 km2 UTM square); (3) home range scale (5×5 km2 UTM square); and (4) landscape level scale (9×9 km2 UTM square containing the above mentioned ones). Topographic, disturbance, climatic and land use factors were measured on
a geographic information system (GIS) at occupied and unoccupied UTM squares. Logistic regression was performed by means of
a stepwise addition procedure. We tested whether inclusion of new subset of variables improved the models by increasing the
area under the receiver operator characteristic plot. At nest site scale, only topographic factors were considered as the
most parsimonious predictors. Probability of species occurrence increases with slope in craggy areas at lower altitudes. At
the 3×3 km2 scale, climate and disturbance variables were included. At home range and landscape level scales, models included climate,
disturbance, topographic and land use factors. Higher temperatures in January, template ones in July, higher rainfall in June,
lower altitudes and higher slope in the sample unit increase probability of occurrence of Bonelli’s eagle at broadest scales.
The species seems to prefer disperse forests, scrubland and agricultural areas. From our results, we consider that there is
a hierarchical framework on habitat selection procedure. We suggest that it is necessary to analyse what key factors are affecting
Bonelli’s eagle nest-site selection at every study area to take steps to ensure appropriate conservation measures. The combination
of regression modelling and GIS will become a powerful tool for biodiversity and conservation studies, taking into account
that application depends on sampling design and the model assumptions of the statistical methods employed. Finally, predictive
models obtained could be used for the efficient monitoring of this scarce species, to predict range expansions or identify
suitable locations for reintroductions, and also to design protected areas and to help on wildlife management. 相似文献
5.
Integrating individual habitat choices and regional distribution of a biodiversity indicator and top predator 总被引:7,自引:0,他引:7
Aim Habitat selection studies have mainly focused on behavioural choices of individuals or on the habitat‐related regional distribution of a population, with little integration of the two approaches. This is despite the fact that traditional biogeography theory sees the geographical distribution of a species as the collective outcome of the adaptive habitat choices of individuals. Here, we integrate individual habitat choices with regional distribution through a bottom‐up Geographical Information System (GIS)‐based approach, by using a 9‐year data set on a large avian predator, the eagle owl (Bubo bubo L.). We further examine the potential population level and biodiversity consequences of this approach. Location The study was conducted in the Trento Region (central‐eastern Italian Alps) and in six other areas of the nearby Lombardia Region in the central Alps. Methods We used stepwise logistic regression to build a habitat suitability model discriminating between eagle owl territories and an equal number of random locations. The model was applied to the whole Trento region by means of a GIS so as to predict suitable habitat patches. The predicted regional distribution (presence–absence in 10‐km grid quadrats) was then compared with the observed one. Furthermore, we compared estimates of biodiversity in quadrats with and without eagle owls, so as to test whether the presence of this top predator may signal macro‐areas of high biodiversity. Results The logistic habitat suitability model showed that, compared with a random distribution, eagle owls selected low‐elevation breeding sites with high availability of prey‐rich habitats in their surroundings. Breeding performance increased with the availability of prey‐rich habitats, confirming the adaptiveness of the detected habitat choices. We applied the habitat suitability model to the 6200 km2 study region by means of a GIS and found a close fit between the observed and predicted regional distribution. Furthermore, population abundance was positively related to the availability of habitat defined as suitable by the above analyses. Finally, high biodiversity levels were associated with owl presence and with the amount of suitable owl habitat, demonstrating that modelling habitat suitability of a properly chosen indicator species may provide key conservation information at the wider ecosystem level. Main conclusions Our bottom‐up modelling approach may increase the conservation‐value of habitat selection models, by (1) predicting local and regional distribution, (2) estimating regional population size, (3) stimulating further hypothesis testing, (4) forecasting the population effects of future habitat loss and degradation and (5) aiding in the identification and prioritization of high‐biodiversity areas. 相似文献
6.
Nonmotorized recreation and motorized recreation in shrub‐steppe habitats affects behavior and reproduction of golden eagles (Aquila chrysaetos)
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Different forms of outdoor recreation have different spatiotemporal activity patterns that may have interactive or cumulative effects on wildlife through human disturbance, physical habitat change, or both. In western North America, shrub‐steppe habitats near urban areas are popular sites for motorized recreation and nonmotorized recreation and can provide important habitat for protected species, including golden eagles. Our objective was to determine whether recreation use (i.e., number of recreationists) or recreation features (e.g., trails or campsites) predicted golden eagle territory occupancy, egg‐laying, or the probability a breeding attempt resulted in ≥1 offspring (nest survival). We monitored egg‐laying, hatching and fledging success, eagle behavior, and recreation activity within 23 eagle territories near Boise, Idaho, USA. Territories with more off‐road vehicle (ORV) use were less likely to be occupied than territories with less ORV use (β = ?1.6, 85% CI: ?2.8 to ?0.8). At occupied territories, early season pedestrian use (β = ?1.6, 85% CI: ?3.8 to ?0.2) and other nonmotorized use (β = ?3.6, 85% CI: ?10.7 to ?0.3) reduced the probability of egg‐laying. At territories where eagles laid eggs, short, interval‐specific peaks in ORV use were associated with decreased nest survival (β = ?0.5, 85% CI: ?0.8 to ?0.2). Pedestrians, who often arrived near eagle nests via motorized vehicles, were associated with reduced nest attendance (β = ?11.9, 85% CI: ?19.2 to ?4.5), an important predictor of nest survival. Multiple forms of recreation may have cumulative effects on local populations by reducing occupancy at otherwise suitable territories, decreasing breeding attempts, and causing nesting failure. Seasonal no‐stopping zones for motorized vehicles may be an alternative to trail closures for managing disturbance. This study demonstrates the importance of considering human disturbance across different parts of the annual cycle, particularly where multiple forms of recreation have varying spatiotemporal use patterns that create human–wildlife interactions. 相似文献
7.
基于MAXENT模型的丹顶鹤营巢生境适宜性分析——以扎龙保护区为例 总被引:4,自引:0,他引:4
明确物种繁殖栖息地的潜在分布对于受胁物种的保护与科学管理具有十分重要的意义。扎龙保护区是国际濒危物种丹顶鹤西部迁徙种群的主要繁殖地之一,近年来繁殖种群数量波动较大。通过GIS空间技术平台,利用MAXENT模型,结合2012—2013年丹顶鹤(Grus japonensis)营巢分布点和环境特征变量,对扎龙保护区丹顶鹤营巢生境的适宜性进行了分析。结果表明:模型的评价效果达到优秀水平(训练集AUC=0.901);绿度(34.9%)、距道路距离(17.1%)、土壤湿度(16.3%)、海拔(15.7%)是丹顶鹤营巢生境的主要环境特征变量;核心区中部和南部是丹顶鹤主要的适宜营巢分布区,缓冲区和实验区有少量的适宜营巢区分布,丹顶鹤适宜营巢生境面积为35857.35hm~2,占保护区总面积的17.07%。建议在重点管理核心区的同时,对缓冲区和实验区的小面积芦苇沼泽给予更多关注。 相似文献
8.
Variations in habitat quality impact on breeding success, leading to strong selection pressure for the best sites to be occupied
first during a population increase and last during a decline. Coupled with dispersal and metapopulation processes, the result
is that snapshot surveys of wildlife distributions may fail to reveal core areas that conservation seeks to protect. At a
local scale, territory occupancy is a good indicator of quality but data are not readily available to assess occupancy for
rarer species, in remote areas, and over large spatial extents. We introduce temporal suitability analysis as a way to generate
an analogue of occupancy from a single survey and illustrate it using data on the little bustard in Spain. We first used Generalised
Additive Modelling (GAM) to build a predictive distribution model using Geographic Information System (GIS) coverages and
satellite imagery, and then applied the model retrospectively to a time series of satellite images to produce one distribution
map for each year. These annual maps differed in the extent of Spain predicted as suitable for little bustards. By overlaying
the maps, we identified areas predicted as suitable in one to n years. We show that this temporal suitability map correlates with a conventional habitat suitability map based on a single
year but contains extra information on hierarchical use of habitats and the lag between suitability and use. The technique
may be applied at a variety of spatial scales to reveal changes in expected occupancy as land use or external factors determining
land cover types vary over time. 相似文献
9.
Capsule Nests of Cinereous Vultures were found to be located farther from roads, villages and the edge of large vegetation patches. They preferred large vegetation patches containing extensive Cork Oak cover on steeper slopes and with lower solar radiation. Less than 8% of the study area was predicted to be suitable for nesting.Aims To generate a predictive habitat suitability map for the Cinereous Vulture's nesting-habitat on a fine scale for conservation applications within its breeding range.Methods Habitat features of 43 nest-locations and random points were compared in order to identify nest-habitat selected in the region of the Hornachuelos Natural Park (Spain). A logistic regression approach was used to create habitat models.Results Compared with random points, nests were found to be located farther from roads, villages and patch edges, and in large vegetation patches containing extensive Cork Oak cover on steeper slopes with lower solar radiation. The predictive map revealed that less than 8% of the study area had a greater probability of occupancy than 0.8.Conclusions Most habitats in the study area are unsuitable for nesting suggesting that conservation of the best suitable areas is important. The fine-scale predictive map approach may be valuable in designating conservation priority areas. 相似文献
10.
Re‐establishing the pecking order: Niche models reliably predict suitable habitats for the reintroduction of red‐billed oxpeckers
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Riddhika Kalle Leigh Combrink Tharmalingam Ramesh Colleen T. Downs 《Ecology and evolution》2017,7(6):1974-1983
Distributions of avian mutualists are affected by changes in biotic interactions and environmental conditions driven directly/indirectly by human actions. The range contraction of red‐billed oxpeckers (Buphagus erythrorhynchus) in South Africa is partly a result of the widespread use of acaracides (i.e., mainly cattle dips), toxic to both ticks and oxpeckers. We predicted the habitat suitability of red‐billed oxpeckers in South Africa using ensemble models to assist the ongoing reintroduction efforts and to identify new reintroduction sites for population recovery. The distribution of red‐billed oxpeckers was influenced by moderate to high tree cover, woodland habitats, and starling density (a proxy for cavity‐nesting birds) with regard to nest‐site characteristics. Consumable resources (host and tick density), bioclimate, surface water body density, and proximity to protected areas were other influential predictors. Our models estimated 42,576.88–98,506.98 km2 of highly suitable habitat (0.5–1) covering the majority of Limpopo, Mpumalanga, North West, a substantial portion of northern KwaZulu‐Natal (KZN) and the Gauteng Province. Niche models reliably predicted suitable habitat in 40%–61% of the reintroduction sites where breeding is currently successful. Ensemble, boosted regression trees and generalized additive models predicted few suitable areas in the Eastern Cape and south of KZN that are part of the historic range. A few southern areas in the Northern Cape, outside the historic range, also had suitable sites predicted. Our models are a promising decision support tool for guiding reintroduction programs at macroscales. Apart from active reintroductions, conservation programs should encourage farmers and/or landowners to use oxpecker‐compatible agrochemicals and set up adequate nest boxes to facilitate the population recovery of the red‐billed oxpecker, particularly in human‐modified landscapes. To ensure long‐term conservation success, we suggest that the effect of anthropogenic threats on habitat distributions should be investigated prior to embarking on a reintroduction program, as the habitat in the historical range may no longer be viable for current bird populations. 相似文献
11.
The role of conservative versus innovative nesting behavior on the 25‐year population expansion of an avian predator
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Andreia Dias Luís Palma Filipe Carvalho Dora Neto Joan Real Pedro Beja 《Ecology and evolution》2017,7(12):4241-4253
Species ranges often change in relation to multiple environmental and demographic factors. Innovative behaviors may affect these changes by facilitating the use of novel habitats, although this idea has been little explored. Here, we investigate the importance of behavior during range change, using a 25‐year population expansion of Bonelli's eagle in southern Portugal. This unique population is almost exclusively tree nesting, while all other populations in western Europe are predominantly cliff nesting. During 1991–2014, we surveyed nest sites and estimated the year when each breeding territory was established. We approximated the boundaries of 84 territories using Dirichlet tessellation and mapped topography, land cover, and the density of human infrastructures in buffers (250, 500, and 1,000 m) around nest and random sites. We then compared environmental conditions at matching nest and random sites within territories using conditional logistic regression, and used quantile regression to estimate trends in nesting habitats in relation to the year of territory establishment. Most nests (>85%, n = 197) were in eucalypts, maritime pines, and cork oaks. Nest sites were farther from the nests of neighboring territories than random points, and they were in areas with higher terrain roughness, lower cover by agricultural and built‐up areas, and lower road and powerline densities. Nesting habitat selection varied little with year of territory establishment, although nesting in eucalypts increased, while cliff nesting and cork oak nesting, and terrain roughness declined. Our results suggest that the observed expansion of Bonelli's eagles was facilitated by the tree nesting behavior, which allowed the colonization of areas without cliffs. However, all but a very few breeding pairs settled in habitats comparable to those of the initial population nucleus, suggesting that after an initial trigger possibly facilitated by tree nesting, the habitat selection remained largely conservative. Overall, our study supports recent calls to incorporate information on behavior for understanding and predicting species range shifts. 相似文献
12.
The United States is rapidly expanding production of renewable energy to meet increased energy demands and reduce greenhouse gas emissions. Wind energy is at the forefront of this transition. A central challenge is understanding the nexus between wind energy development and its capacity for negative effects on wildlife causing population declines and habitat loss. Collaboration among conservationists and developers, early in the planning process, is crucial for minimizing wind-wildlife conflicts. Such collaborations require data showing where wind and wildlife impacts occur. To meet this challenge and inform decision-making, we provide natural resource agencies and stakeholders information regarding where future wind turbines may occur, and the potential affects on natural resource management, including the conservation of priority species and their habitats. We developed a machine learning model predicting suitability of wind turbine occurrence (hereafter, wind turbine suitability) across an eight-state region in the United States, representing some of the richest areas of wind potential. Our model incorporates predictor variables related to infrastructure, land ownership, meteorology, and topography. We additionally created a constraint layer indicating areas where wind would likely not be developed because of zoning, protected lands, and restricted federal agency proximity guidelines. We demonstrate how the predictive wind turbine suitability model informs conservation planning by incorporating animal movement models, relative abundance models coupled with spatial conservation planning software, and population density models for three exemplar, high priority species often affected by wind energy: whooping cranes (Grus americana), golden eagles (Aquila chrysaetos), and lesser prairie-chickens (Tympanuchus pallidicinctus). By merging the wind turbine and biological models, we identified conservation priority areas (i.e., places sharing high suitability for wind turbines and species use), and places where wind expansion could minimally affect these species. We use our “species-wind turbine occurrence relationships” to demonstrate applications, illustrating how forecasting areas of wind turbine suitability promotes wildlife conservation. These relationships inform wind energy siting to reduce negative ecological impacts while promoting environmental and economic viability. 相似文献
13.
Silke Hein Julia Voss Hans-Joachim Poethke Schröder Boris 《Journal of Insect Conservation》2007,11(3):221-240
One goal of conservation biology is the assessment of effects of land use change on species distribution. One approach for
identifying the factors, which determine habitat suitability for a species are statistical habitat distribution models. These
models are quantitative and can be used for predictions in management scenarios. However, they often have one major shortcoming,
which is their complexity. This means that they need several, often costly-to-determine parameters for predictions of species
occurrence. We first used habitat suitability models to investigate and determine habitat preferences of three different Orthoptera
species. Second, we compared the predictive powers of simple habitat suitability models considering only the ‘habitat type’
as predictor with more complex models taking different habitat factors into account. We found that the habitat type is the
most reliable and robust factor, which determines the occurrence of the species studied. Thus, analyses of habitat suitability
can easily be carried out on the basis of existing vegetation maps for the conservation of the three species under study.
Our results can serve as a basis for the estimation of spatio-temporal distribution and survival probabilities of the species
studied and might also be valuable for other species living in dry grasslands. 相似文献
14.
15.
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
16.
Luc Barbaro Laurent Couzi Vincent Bretagnolle Julien Nezan Fabrice Vetillard 《Biodiversity and Conservation》2008,17(5):1073-1087
Bird conservation can be challenging in landscapes with high habitat turnover such as planted forests, especially for species
that require large home ranges and juxtaposition of different habitats to complete their life cycle. The eurasian hoopoe (Upupa epops) has declined severely in western Europe but is still abundant in south-western France. We studied habitat selection of hoopoes
in pine plantation forests using a multi-scale survey, including point-counts at the landscape level and radio-tracking at
the home-range scale. We quantified habitat use by systematically observing bird behaviour and characterized foraging sites
according to micro-habitat variables and abundance of the main prey in the study area, the pine processionary moth (Thaumetopoea pityocampa). At the landscape scale, hoopoes selected habitat mosaics of high diversity, including deciduous woods and hedgerows as
main nesting sites. At the home-range scale, hoopoes showed strong selection for short grassland vegetation along sand tracks
as main foraging habitats. Vegetation was significantly shorter and sparser at foraging sites than random, and foraging intensity
appeared to be significantly correlated with moth winter nest abundance. Hoopoe nesting success decreased during the three
study years in line with processionary moth abundance. Thus, we suggest that hoopoes need complementation between foraging
and breeding habitats to establish successfully in pine plantations. Hoopoe conservation requires the maintenance of adjacent
breeding (deciduous woods) and foraging habitats (short swards adjacent to plantation edges), and consequently depends on
the maintenance of habitat diversity at the landscape scale. 相似文献
17.
18.
Dutta Sutirtha Rahmani Asad R. Jhala Yadvendradev V. 《European Journal of Wildlife Research》2011,57(3):615-625
The endemic great Indian bustard (GIB) is evolutionarily trapped between open nesting and k-selection that endangers its persistence under prevailing levels of habitat loss and hunting. A global population of about
300 birds is further fragmented into eight populations in the states of Rajasthan (shared with Pakistan), Maharashtra, Andhra
Pradesh, Gujarat, Karnataka, and Madhya Pradesh in India. The largest population of 100–125 birds exists in Jaisalmer, Barmer,
and Bikaner districts of Rajasthan. Remaining populations number less than 35 birds each. Prevalent GIB conservation strategies
use legislation to (a) secure traditional breeding areas by declaring small Protected Areas (PA) or (b) protect vast areas
with varied human land uses. The vagrant nature of GIB reduces the benevolent effect of small PAs, while large reserves alienate
people by curbing legitimate subsistence rights through strict legislation. These factors along with ill-informed habitat
management challenge the current PA approach, even causing local extinctions. Population viability analysis shows that GIB
populations of ≤35 birds can persist only under unrealistic conditions of first year mortality ≤40%, and no human caused mortality
of adult birds. Even the largest population (≥100 birds) is sensitive to additional loss of adult birds to human causes. With
current levels of hunting in Pakistan, extinction is a real threat. A landscape conservation strategy using conservation/community
reserve concept that includes controlled traditional land uses with GIB-friendly infrastructural development is needed. The
declining rate of GIB populations calls for immediate commencement of ex situ conservation breeding programs. 相似文献
19.
Predicting the distribution of four species of raptors (Aves: Accipitridae) in southern Spain: statistical models work better than existing maps 总被引:5,自引:0,他引:5
Aim To test the effectiveness of statistical models based on explanatory environmental variables vs. existing distribution information (maps and breeding atlas), for predicting the distribution of four species of raptors (family Accipitridae): common buzzard Buteo buteo (Linnaeus, 1758), short‐toed eagle Circaetus gallicus (Gmelin, 1788), booted eagle Hieraaetus pennatus (Gmelin, 1788) and black kite Milvus migrans (Boddaert, 1783). Location Andalusia, southern Spain. Methods Generalized linear models of 10 × 10 km squares surveyed for the presence/absence of the species by road census. Statistical models use as predictors variables derived from topography, vegetation and land‐use, and the geographical coordinates (to take account of possible spatial trends). Predictions from the models are compared with current distribution maps from the national breeding atlas and leading reference works. Results The maps derived from statistical models for all four species were more predictive than the previously published range maps and the recent national breeding atlas. The best models incorporated both topographic and vegetation and land‐use variables. Further, in three of the four species the inclusion of spatial coordinates to account for neighbourhood effects improved these models. Models for the common buzzard and black kite were highly predictive and easy to interpret from an ecological point of view, while models for short‐toed eagle and, particularly, booted eagle were not so easy to interpret, but still predicted better than previous distribution information. Main conclusions It is possible to build accurate predictive models for raptor distribution with a limited field survey using as predictors environmental variables derived from digital maps. These models integrated in a geographical information system produced distribution maps that were more accurate than previously published ones for the study species in the study area. Our study is an example of a methodology that could be used for many taxa and areas to improve unreliable distribution information. 相似文献
20.
Pascual López-López Clara García-Ripollés Álvaro Soutullo Luis Cadahía Vicente Urios 《Biodiversity and Conservation》2007,16(13):3755-3780
The Bonelli’s eagle (BE) is considered by the European Union as a high-priority species for conservation in the Valencian
Community (East of Spain). However, in 2006 the European Union opened a legal procedure against the Spanish Kingdom, accused
of lacking of an adequate network of special protected areas (SPAs) to preserve the BE in the region. Here we evaluate whether
important bird areas (IBAs) and SPAs network is enough to preserve this species, on the basis of a thorough analysis of habitat
preferences. A GAP analysis is performed to conduct a revision of current SPAs and BirdLife proposed IBAs. Our results suggest
that the current network of SPAs becomes insufficient to protect the BE. The IBAs network, although improves the current network
of SPAs, increasing the percentage of BE potential habitat included, also results inadequate. We propose a new SPAs network
according to the potential suitable habitat for the species. Given the trade-off between financial investment and the conservation
of biodiversity, we propose to maximize the surface of potential habitat included in the protected network minimizing the
surface of the region that would be necessary to protect, thus avoiding an unnecessary expense and otherwise unrealistic results. 相似文献