Dynamics of public attitudes toward bears and the role of bear hunting in Croatia

Successful carnivore conservation depends on public attitudes and acceptance levels of carnivores, and these are likely to change as circumstances change. Attitude studies repeated in time that can demonstrate such change are rare. Our study surveyed Croatian rural inhabitants in 2002 and in 2008 and analyzed their responses to detect a change in attitudes toward brown bears (Ursus arctos) over time. Important developments occurring in Croatia at the time of our research included a more centralized and more clearly defined bear management strategy, and an increase in the bear population. We constructed models to explain respondent’s value orientations, their level of perceived threat and their acceptance capacity for bears. Findings show that while value orientations and the overall level of perceived threat did not change over time, bear acceptance capacity was reduced. This suggests that the increase in the bear population and perhaps the more centralized bear management reduced respondents’ willingness to accept a larger bear population. We conclude that continuous public involvement in bear management is essential in order to maintain a feeling of control over the bear among the local population. Furthermore we argue that hunting is an important form of public involvement in the region, serving to reinforce existence and bequest values of the bear and increase its public acceptance.     

Black bear resource selection in the northeast Cascades, Washington

We examined resource selection of black bears in the northeast Cascades of Washington at two spatial scales. Specifically, we compared habitats selected for within home ranges to those available in the study area, and habitats selected for versus those available within home ranges. Compositional analysis showed selection of similar habitats at each spatial scale, with some differences. In the dry climate of the eastern Cascades, black bears appeared to locate home ranges within habitats that would provide abundant food resources, such as riparian and deciduous forests, meadows and shrubfields. Once established in a home range, black bears selected for a mosaic of habitat types that provided security cover in proximity to food resources, such as riparian and deciduous forests, other forest types and meadows.     

Grizzly bear response to human development and activities in the Bow River Watershed, Alberta, Canada

Few studies have reported the effects of multiple human activities on grizzly bears, Ursus arctos. We document the degree of grizzly bear response to various human developments as a function of multiple interacting variables based on observed median distances to roads, trails and development features in a landscape where human presence is widespread. Female grizzly bears remained further than males from paved roads regardless of habitat quality or time of day. Males were found closer to paved roads when within or adjacent to high quality habitat and during the period of least human activity. The combination of traffic volume and highway configuration, however, overrides a bear’s attraction to high quality habitats for high-speed, high-volume, highways. Avoidance of busy transportation corridors was strongest in the adult segment of the population. Bears were found closer to trails during the human inactive period when within high quality habitat and further from trails when distant to high quality habitat. Our data indicated an inverse relationship between the sexes in response to vehicles and traffic noise compared to the response to human settlement and encountering people. Female bears were found further away than males in relation to vehicles and traffic noise, yet found closer than males to human settlement and places where people may be encountered. Those males that were more willing to exploit high quality habitat near roads, did so at night and where hiding cover was present. Adult females were the most risk-averse cohort, choosing to avoid humans instead of seeking out high quality habitats. Adult female grizzly bears were influenced most by human activities and development. Management agencies must maintain access to high quality habitat, especially for adult females, and create new opportunities to support the reproductive potential of the population.     

High human density in the irreplaceable sites for African vertebrates conservation

The identification of priority sites that ensure the achievement of conservation goals is key to direct conservation efforts. An estimation of the level of vulnerability of each priority area allows the identification of sites that need urgent conservation action. We present a systematic reserve selection for 1654 African mammals and amphibians that uses habitat suitability models as estimates of the area occupied by each species. These are based on the geographic range and habitat preferences for each species, which we collected in the framework of the World Conservation Union (IUCN) Global Amphibian Assessment and IUCN Global Mammal Assessment. Our results showed that in addition to existing protected areas, approximately 2.8 million km² of land is irreplaceable to achieve the protection of 10% of the area occupied by all amphibians and mammals. This figure is higher than previous estimates from other studies. Most irreplaceable sites are located in the sub-Saharan region. More than half (55%) of the irreplaceable sites have high human population density; for only 17% the human population density is low. African amphibians and mammals have therefore to be conserved in densely populated areas where innovative management policies will be required to accommodate conservation successfully.     

An evaluation of field and non-invasive genetic methods to estimate brown bear (Ursus arctos) population size

Estimates of population size and density are essential for successful management and conservation of any species. Although there are a variety of methods available for estimating abundance and density of populations, most studies rely on only one estimator and very few studies have compared and critically evaluated the adequacy and the cost of these methods. We used the brown bear (Ursus arctos) in south-central Sweden to compare the performance of three different methods of estimating population size, including methods based on conventional field data as well as on non-invasive genetic data. The method based on observations of females with cubs underestimated the true population size, as the estimates were below the number of unique genotypes determined from faecal data inside the study area. The best traditional method was based on observations of bears from a helicopter. The genetic method using the closed population MARK estimator, as recommended in a previous study, seemed to perform the best. We conclude that approximately 223 (188-282) bears were present in our 7328 km² study area during 2001 and 2002 and suggest that this hunted brown bear population has been relatively stable for about ten years. The non-invasive genetic method was less expensive than the most reliable traditional field method (a CMR method based on observations of bears from a helicopter), and preferable from an ethical point of view. We recommend that future studies using non-invasive genetic methods based on collected faecal samples should aim at collecting 2.5-3 times the number of faecal samples as the “assumed” number of animals.     

A conservation framework for the golden eagle in Scotland: Refining condition targets and assessment of constraint influences

Conservation strategies have three elements: species protection, site protection and, the most challenging component, conservation in the wider environment. Watson and Whitfield [Watson, J., Whitfield, P., 2002. A conservation framework for the golden eagle Aquila chrysaetos in Scotland. Journal of Raptor Research 36(1 Suppl.), 41-49.] proposed a conservation framework for the golden eagle in Scotland whose main innovation, taking a lead from EU conservation Directives, was to incorporate the concept of favourable condition and its maintenance by implementing conservation policies that are regionally targeted at known constraints in the wider environment. Three criteria were suggested to judge favourable condition: a national abundance target of breeding pairs, national and regional targets for breeding productivity, and regional targets for the extent of suitable habitat which is occupied by breeding pairs. Here we refine these criteria, first to take the national abundance target and use it to set regional targets. Distribution targets were implicitly incorporated by this process because abundance targets were set regionally, with regard to the proportion of known territories which should be occupied. This allowed us to dispense with the distribution criterion as originally proposed. Our next refinement was to base regional demographic targets not only on breeding productivity, but also on indirect measures of survival (which are likely to have more influence on population dynamics). Despite apparent overall population stability over the last 20 years, the national golden eagle population failed to meet the abundance target and only 3 of 16 regions where eagles have occupied territories since 1982 were considered to be in favourable condition. The key constraint preventing favourable condition being met was persecution, predominantly in some areas managed for grouse shooting. The advantages of a conservation framework over similar approaches, such as species action plans, are highlighted.     

The performance of procedures for selecting conservation areas: waterbirds in the UK

In recent years, much attention has been directed to the ways in which the most important areas for inclusion in reserve networks can be identified, and the most effective ways in which existing networks can be expanded. In contrast, rather little attention has been paid to the present and likely future performance of the approaches that have actually been employed. Using Wetland Bird Survey data, the effectiveness of the current Special Protection Area (SPA) network in the UK was assessed by comparing annual counts for 17 species of migratory waterbird on SPAs with the numbers supported by hypothetical site networks selected by five alternative site-selection methods. These analyses suggest that focusing on complementarity between component sites rather than applying criteria to each site individually improved the level of representation for each species, conserved a greater percentage of the national total across the 17 species and was robust over time.     

Prioritizing avian conservation areas for the Yellowstone to Yukon Region of North America

Prioritizing new areas for conservation in the Rocky Mountains of North America is important because the current intensity and scale of human development poses an immediate threat to biodiversity. We identified priority areas for avian biodiversity within a 3200-km corridor from Yellowstone National Park in Wyoming, US to the Yukon in Canada (the Y2Y region). We applied the conservation planning tool, MARXAN, to summarize 21 avian values. MARXAN minimizes the area delineated, while simultaneously incorporating multiple criteria (species richness representation, spatial clustering) and biodiversity targets into a single mappable solution. We prioritized avian biodiversity ‘hotspots’ at continental and ecoprovincial scales based on: (1) avian species richness; and (2) habitat associations of 20 focal species. At the continental scale, the single best solution represented 19% of the Y2Y region; 29% of this solution overlapped with existing protected areas. In northern Y2Y, large contiguous areas with high avian value were concentrated on the western edge of the continental divide. In southern Y2Y, contiguous areas were smaller and more numerous than in the north. In contrast to the majority of studies prioritizing conservation areas, we explored the effect of varying the extent of the target region by analyzing data at the scale of the entire Y2Y region and for eight ecoprovinces separately. We found that (1) large contiguous patches characterized only three ecoprovinces, while for the remaining ecoprovinces, numerous single scattered habitat patches of varying sizes were required to meet conservation goals; and (2) generally, only a small percentage of sites was already protected within the existing protected areas network. Our results are important for conservation planners and resource managers in the Y2Y region for incorporating areas of high conservation value for birds at regional and ecoprovincial scales during conservation project design and adaptive planning.     

Landscape evaluation of female black bear habitat effectiveness and capability in the North Cascades, Washington

We used logistic regression to derive scaled resource selection functions (RSFs) for female black bears at two study areas in the North Cascades Mountains. We tested the hypothesis that the influence of roads would result in potential habitat effectiveness (RSFs without the influence of roads) being greater than realized habitat effectiveness (RSFs with roads). Roads consistently had a negative influence on black bear RSFs across seasons and study areas. Roads reduced habitat effectiveness during all seasons at both study areas and changes in the potential habitat values ranged from 1.7% to 16.9%. The greatest reduction in habitat values occurred during the early-season on the west-side study area due to high open road densities. These results support the hypothesis that roads reduce habitat effectiveness for black bears. The influence of roads could be reduced through road closures to reduce open road densities and limit traffic volumes. We then used the scaled RSFs in a habitat-based population model to assess the influences of timber harvest and roads on potential black bear population sizes. On the west-side study area the potential black bear population size was most influenced by moderate use roads and timber harvest during the early-season (41% reduction). On the east-side study area, low use roads had the greatest effect on potential black bear population during the early-season (10% reduction). During the late-season, in both study areas, roads had less influence on the potential population sizes as bears were able to access habitats away from roads. The habitat-population model provided reasonable estimates of bear densities compared to other study areas with similar habitats and could be extrapolated to estimate potential black bear populations in other areas with similar habitats. This approach may provide a useful link between the landscape ecology and population biology of black bears, and could eventually be useful in the development of habitat-based population viability analyses.     

Incorporating ontogenetic dispersal, ecological processes and conservation zoning into reserve design

Computational methods for marine reserve design are frequently used as decision-support tools for the identification of conservation areas. Most reserve-selection algorithms minimise the cost of the reserve system whilst aiming to meet specified biodiversity objectives. Here, we extend a widely-used selection algorithm, Marxan, to incorporate several important considerations related to biodiversity processes and management. First we relax the scorched earth assumption to allow conservation features in non-reserve zones to contribute explicitly to conservation objectives. To achieve this, we generate conservation targets at landscape scales rather than focusing purely on the representation of features within reserves. Second, we develop the notion of spatial dependencies further to incorporate spatial heterogeneity in the value of individual conservation features such as habitat types. We use the example of ontogenetic migrations of fish from mangroves to coral reefs because it nicely demonstrates how spatial ecological processes generate predictable heterogeneity in habitat value that should be considered in the reserve design process. Lastly, we show how habitat value can be disaggregated into ecosystem processes and services. Using a case study for the Belize Barrier Reef we compare reserve networks generated using our new approach with the results of traditional analyses. Consideration of the contribution of different protection zones, connectivity among habitats and more complex management goals resulted in up to a 52% increase in the mean biomass of commercially and ecologically-important fish species represented in the landscape. Our approach strengthens the ecological basis of reserve-design algorithms and might facilitate the uptake of ecosystem-based management into reserve design.     

The cost of postponing biodiversity conservation in Mexico

Though Neotropical countries are the most species rich in the world, their biodiversity is threatened by the loss of native vegetation. Land conversion in Mexico during the last 30 years has been extensive and is representative of that of other developing countries. However, the effects of land use change on the required size and configuration of an adequate biological conservation area network are largely unknown. It is shown here that endemic mammals in Mexico could have been protected considerably more economically if a conservation plan had been implemented in 1970 than is possible today due to extensive conversion of primary habitats. Analysis of the distributions of 86 endemic mammal species in 1970, 1976, 1993, and 2000 indicates that the distributions of 90% of the species shrank during this 30-year period. At each time step, optimal conservation area networks were selected to represent all species. 90% more land must be protected after 2000 to protect adequate mammal habitat than would have been required in 1970. In addition, under a realistic conservation budget, 79% fewer species can be represented adequately in a conservation area network after 2000 compared to 1970. This provides an incentive for rapid conservation action in Mexico and other biodiversity hotspots with comparable deforestation rates, including Burma, Ecuador, Indonesia, the Philippines, and Sri Lanka. Due to ongoing habitat degradation, the efficiency of a conservation plan decreases with delays in its implementation.     

棕壤和蛭石对外源钾的固定和释放特征

在外源钾施入量为2800mgkg-1条件下,供试耕地棕壤的固钾容量高达1450mgkg-1。在试验条件下,棕壤对钾素的固定量随外源钾施入量的增加而增加。蛭石对钾素的固定量具有随外源钾的施入量增加而呈线性增大的规律,其中0.3mm~0.1mm粒级蛭石对于钾素的固定量要高于1mm~0.3mm和<0.1mm两粒级蛭石对钾素的固定量。蛭石和棕壤对外源钾的固定率表现为随固钾量的增加而趋于降低的规律,但钾素释放量却随之提高。     

The emerging significance of bioacoustics in animal species conservation

This review reports on the effects of human activities on animal acoustic signals published in the literature from 1970 to 2009. Almost 5% of the studies on variation in animal communication tested or hypothesised on human impacts, and showed that habitat fragmentation, direct human disturbance, introduced diseases, urbanization, hunting, chemical and noise pollution may challenge animal acoustic behaviour. Although acoustic adaptations to anthropogenic habitats have been documented, human impacts have most often generated neutral variation or potential maladaptive responses. Negative impacts have been postulated in the sexual signals of fishes, amphibians, birds, and mammals; these are concerning as any maladaptive alteration of sexual behaviour may have direct bearings on breeding success and ultimately population growth rate. Acoustic communication also facilitates other vital behaviours influenced by human-driven perturbations. Bat and cetacean echolocation, for instance, is disrupted by noise pollution, whereas bird and mammal alarming is also affected by introduced diseases and hunting. Mammal social signals are sensitive to noise pollution and hunting, and birds selecting habitats by means of acoustic cues are especially vulnerable to habitat loss. Anthropogenic intervention in these cases may have a negative impact on individual survival, recruitment and group cohesion, limiting rescue-effects and triggering Allee effects. Published evidence shows that acoustic variation may be used as an early-warning indicator of perturbations even when not directly affecting individual fitness. Acoustic signalling can be studied in a broad range of ecosystems, can be recorded, analyzed, synthesised and played back with relative ease and limited economic budget, and is sensitive to many types of impacts, thus can have great conservation significance.     

不同施肥处理对棕壤腐殖酸组成和性质的影响

23年定位试验结果表明:施用有机肥可提高土壤腐殖酸含量, HA/FA升高,土壤胡敏酸的羧基/酚羟基比升高,E4 /E6 值较高。施化肥处理HA/FA下降,羧基/酚羟基比下降,E4 /E6 值下降。有机无机配施HA/FA下降较明显,其它指标介于有机肥和化肥之间。有机无机配施处理土壤活性胡敏酸平均含量高于有机肥和化肥。松结态腐殖酸占总腐殖酸的10% ~20%。胡敏酸占3% ~8%,富里酸占6% ~11%。施肥可显著降低松结态腐殖酸、胡敏酸和富里酸的比例。化肥的施用可促进紧结态的腐殖酸向松结态的转化,加速地力的消耗。有机无机配施处理可较大幅度地提高松结态胡敏酸的比例,而减低松结态富里酸的比例。     

Threat syndromes and conservation of the Australian flora

The status of the Australian flora was reviewed by compiling published information on all critically endangered and endangered species listed federally in 2004. Threatening processes were categorised and their contributions to past, present and future declines were assessed. The information was cross-referenced against State agency information and field knowledge. Land clearance for agriculture (grazing and cropping) and urbanization have been the primary causes of range contractions and habitat loss in the past, responsible for the current status of the majority of threatened Australian plants. In the future, land clearance will remain important but new issues are emerging. Many species are now at risk from demographic and environmental uncertainty alone. Threats growing in importance include disease, salinity, invasive species and changed disturbance regimes. Many species are subject to common, landscape-level threats. A key issue to emerge from our analysis is that most species are threatened by a number of interacting factors - threat syndromes. Several future risks may be mitigated effectively by simple, low-cost changes in policy, such as more stringent controls on land clearance, strategic fire management, and firmer control on the importation of plant species. Other factors will require greater effort and new strategies to mitigate, including social and legal initiatives in urban landscapes and broad strategies for pathogens, climate change and other landscape-level processes.     

Grouping and prioritization of vascular plant species for conservation: combining natural rarity and management need

National and International Red Lists and Legal Acts specify species with conservation needs, mainly on the basis of personal experiences. For effective conservation we need scientifically justified prioritization and grouping of these species. We propose a new combined approach where species are grouped according to the similar activities needed for their conservation. We used the national list of vascular plant species with conservation need for Estonia (301 species), and linked these species to eight qualitative conservation characteristics, four reflecting natural causes of rarity (restricted global distribution; restricted local distribution within a country; always small populations; very rare habitat type), and four connected with nature management (species needing the management of semi-natural grasslands; species needing local disturbances like forest fires; species needing traditional extensive agriculture; species which may be threatened by collecting). Only one positive association occurred among the characteristics - between restricted local distribution and small size of populations. Thus, natural causes of rarity and management aspects are not overlapping, and both should be used in conservation activities. Species grouping by different conservation characteristics allows one to focus on species groups with similar conservation needs instead of individual species. Prioritization of species with conservation needs can be based on the number of conservation characteristics that are associated with a particular species. Our prioritization did not correlate with the categories of the national Red Data Book, but a positive association was found with legal protection categories. The legislation, however, covers only the natural causes of rarity. We propose a new combined approach for plant species’ conservation planning that starts by considering human induced rarity and progresses through to natural rarity causes.     

长期轮作施肥对棕壤磷素形态及转化的影响

对沈阳地区棕壤定位试验地各施肥处理土壤按Hed ley等建议的分级方法进行测定。结果表明,棕壤磷中残留态含量最高,无机磷主要以NaOH-P i和HC l-P i形态存在,有机磷主要以NaOH-Po形态存在,NaHCO3-Po在各组分中所占比例最小。施用有机肥能明显增加潜在活性有机磷(NaOH-Po)的数量。1.0mol L-1HC l浸提的Ca-P i存在着缓慢的动态转化过程,是棕壤中的潜在磷源。     

Modelling the spatial distribution of human-caused grizzly bear mortalities in the Central Rockies ecosystem of Canada

We examined the spatial patterns of 297 human-caused grizzly bear mortalities from 1971 to 2002 within the Central Rockies ecosystem (CRE) of Canada to explore relationships between mortalities and variables reflecting human development, terrain, and vegetation. Using logistic regression, we modelled the distribution of grizzly bear mortalities based on local landscape attributes as well as examining variation among demographic status, seasons, and mortality type. Grizzly bear mortalities were concentrated in three main regions of the CRE: (1) Lake Louise; (2) Banff town site; and (3) Alberta Provincial lands near the Red Deer River. We found no evidence for environmental differences in mortality locations between sexes or seasons, while sub-adult male and legal harvest mortalities were more dispersed than other mortalities. Models describing the relative risk of mortality were positively associated with human access, water, and edge features, while negatively associated with terrain ruggedness and greenness indices. Model predictions fit well with independent data. Overall, relatively little of the landscape was secure from human-caused mortality for grizzly bears. This would be most directly remedied by controlling human access.     

Genetic tracking of the brown bear in northern Pakistan and implications for conservation

Asian bears face major threats due to the impact of human activities as well as a critical lack of knowledge about their status, distribution and needs for survival. Once abundant in northern Pakistan, the Himalayan brown bear (Ursus arctos isabellinus) has been exterminated in most of its former distribution range. It presently occurs sparsely, in small populations, the Deosai National Park supporting the largest isolate. This decline might imply a reduction in genetic diversity, compromising the survival of the population. Using a combination of fecal DNA analysis and field data, our study aimed at assessing the size and genetic status of the Deosai population and give guidelines for its conservation and management. Using fecal genetic analysis, we estimated the population to be 40-50 bears, which compares well with the field census of 38 bears. The northern Pakistani brown bear population may have undergone an approximate 200-300-fold decrease during the last thousand years, probably due to glaciations and the influence of growing human population. However, in spite of the presence of a bottleneck genetic signature, the Deosai population has a moderate level of genetic diversity and is not at immediate risk of inbreeding depression. Gene flow might exist with adjacent populations. We recommend careful monitoring of this population in the future both with field observations and genetic analyses, including sampling of adjacent populations to assess incoming gene flow. The connectivity with adjacent populations in Pakistan and India will be of prime importance for the long-term survival of Deosai bears.     

Trends in the use of conservation tillage in US agriculture

Abstract. In 1996 conservation tillage was used on nearly 36% of the cropped area of the USA. This level has remained relatively unchanged over the past few years. The use of conservation tillage varied by crop and was dependent on site-specific factors including soil type, topsoil depth, and local climatic conditions. A number of economic, demographic, geographic, and policy factors have affected the adoption of conservation tillage. While it was not possible to quantify exactly the impact of these factors, it was clear that management complexities and profitability are key factors impeding an increase.