جستجوی مقالات مرتبط با کلیدواژه « خرس قهوه ای » در نشریات گروه « محیط زیست »

The Survey of attitudes of local communities towards carnivores in the natural habitats where these species interact with humans is essential for the management and conservation of these species. In this study, we designed a questionnaire form and 230 people were interviewed to find out the attitude of local communities towards the presence of the brown bear in the Mazandaran province. The independent variables of the analyses which were considered are age, education, bear attacks to humans and on human capital, bear fear, knowledge of local people about bear's role in nature, traditional beliefs of local people and acceptance (1) or non-acceptance (0) of the bear by locals in the habitat. Finally, by using binary logistic regression statistical methods, the attitude of local communities regarding acceptance or rejection of this species was analyzed. The results showed that among the studied variables, those people who are highly knowledgeable, those who are afraid of species and those who have a traditional belief about the species agree with the presence of bears in nature. The results study showed that the knowledge of the local communities about the bear has a positive effect on their attitude and interest in the presence of the bear, and fear of the bear did not cause a negative attitude and a lack of interest in the presence of the bear. But given the increasing conflict in recent years in the province of Mazandaran, economic losses may increase retaliation by local people and jeopardize the survival of the bear.

Protection of habitat connectivity is a major goal of the protection project, especially for large predators. Habitat patches are desirable zones with different distribution in landscape. These patches with various dimensions and sizes include high-performance segments for presence and establishment. Therefore, investigation of the identification process and changes in the patches for different species of wildlife will provide a correct and accurate picture of their distribution status. This study was conducted to investigate the distribution of habitat patches of brown bear on the landscape scale of Sefidkoh area in Lorestan province. In this regard, habitat suitability was first calculated by maximum entropy method using 10 replicates. After validation of the model using the AUC, different thresholds of logistic output were applied to continuous habitat suitability map. NP, PD, ED, LPI, LSI, SHDI and CONTAG metrics were used to evaluate the continuity. The trend of changes in different metrics showed that by decreasing and increasing the threshold value applied to the continuous map, the suitability of the values related to landscape metrics would be affected. High threshold values represent the key habitat and low threshold values give an optimistic view of the distribution of patches. The results showed that the identification of the appropriate threshold for hot spots analysis is prior to analysis of landscape metrics since this threshold depending on the purpose of the study, the number of presence points, model types, and species conditions will be of different utility.

In recent years, the interference of wildlife natural needs such as water, food, shelter and the place of reproduction supply and human needs in natural lands have lead to the serious conflicts between humans and wildlife. One of the most obvious examples of this conflict is the increase in incidents caused by losses incurred by bears to humans, livestock and gardens in Qazvin province. Drafting and implementing a consistent strategic management plan in agreement with areas socio-economic conditions, can be considered an effective solution to reduce conflicts in these areas. In this study, we looked for the strengths and weaknesses as well as opportunities and threats to which environmental management of this province is facing and/or will be faced in future. Then we categorized, weighted and analyzed them, using SWOT analysis. Finally, we applied a quantitative strategic planning matrix (QSPM) to prepare an appropriate strategic management plan to remove or reduce the conflicts. The results showed three principal strategies are as the most important strategies for providing a strategic management plan for reducing Brown Bear conflicts including; (i) Complete implementation of the action plan of brown bears protection with attracting the necessary credits by the Department of Environmental Protection of the Qazvin province, (ii) Education of local communities and promote of effective methods for protecting beehives and gardens from bears' attacks, and (iii) Increasing the number of rangers and equipping the Rangers station in order to better protect of the bears' habitats and Permanent presence of Rangers in hot spot areas.

Brown bear (Ursus Arctos) is classified as a Least Concern (LC) species of the International Union for Conservation of Nature (IUCN), but its population and distribution have decreased during last decades. This study was carried out to assess the habitat suitability for Brown bear and the effective factors affecting its distribution in Naposhteh-Chai watershed.

Maximum Entropy (MaxEnt) approach available in MaxEnt software was used for the habitat suitability modeling of this species from autumn 2015 to autumn 2016. Information layers determined as affecting variables on this species include the slope, aspect, elevation, land use, water resources, human development variables (villages and roads) and climate.

Results showed that 24.4 percent of Naposhteh-Chai watershed were suitable for Brown bear. Based on habitat suitability map, Brown bear preferred elevation range of 1000 to 2100 meters and slope of 10 to 60 percent. Furthermore, existing of densed forests, farmlands, water sources, villages and also aspect and climate, are important factors in the presence of this species.

Results of model evaluation using the area under the curve (ROC= 0.970) showed that prediction of this model are much more accurate than random conditions. Brown bear suitable integrated habitats, are located in Makidi, Oskolu, Naposhteh and Bala Sang areas. Prevention of tourism development in the suitable habitats of Brown bear, and, determination of corridors and movement routs of the species outside of the Naposhteh-Chai watershed in future studies were suggested in the route of this research.

Ecological niche is an area of one or more of the environmental factors in which the growth, reproduction and survival of a living organism is possible. In this study, Maximum entropy method was used to model the distribution and quantification of bear ecological niche in Ilam province. To select the background points, the network bias was used using the kernel density method. 70 percent of the points were used for training and 30 percent were used for the test. The results showed that the model was successful in its running (AUC = 0.97) and had a significant difference with randomized design in all thresholds (P<0.05). In order to determine the variation of the ecological niche of the species in the distribution range, a 50% threshold (0.5) was applied to the habitat suitability map and the output of this map was used to determine the grid range. Grid selection was made according to the home range. For each network, the suitability map was cut and entered the ENMtools software to determine the ecological niches breadth. Non-parametric Mann-Kendall test was used to determine the process of ecological nest width changes. The results showed that altitude, NDVI and distance from semi-dense forests had the most effect on species distribution and bears in Manesht and Qalarang areas have the highest ecological niche breadth. The trend of ecological niche showed that the breadth of ecological niche of species from the northwest of the province to the south east has a significant decreasing trend.

Ghalajeh Protected area as one of the most important Forest habitats in Zagros Mountains is located in Kermanshah province and is known for the Greatest Carnivorous. The aim of this study was modeling the Distribution of brown bear (Ursus arctos) using Maximum Entropy method. For this purpose, 168 Presence Points were collected in the annual period (2017-2018) for studying the habitat of species. 13 environmental variables including slope direction, Compound Topographic Index, elevation, distance from the points of presence of the tribes, distance from the stream, distance from the garden, distance from the river, distance from the road, distance from the village, ecotone, Heat Load Index, Normalized difference vegetation index and slope index were used as effective ecological variables on the species. The validity of the model was measured from the surface below the curve or AUC, which was calculated as 0.86, which indicates the high model's ability to distinguish between suitable and unsuitable habitats. Also, the results of the studying the importance of habitat variables were Jackknife analysis showed that the most important variables in the selection of brown bear habitat in Ghalajeh protected area are distance from the river, distance from the garden and Normalized difference vegetation index.

Understanding of food habits of animals is an important issue to perceive the ecology of species. Distribution, availability and quality of food sources affect the reproduction success of Brown bears. Habitat destruction and consequent biological constraints (including decrease of the prey population and reducing the security of habitats) has reduced the population of this species. The purpose of this study was to study the spring dietary habits of the Brown bear (Ursus arctos) in Golestan National Park. During field activities and finding the places of the brown bear scats, the samples were transferred to laboratory and were coded. Then, the scats were separated by soaking and the residues of the preys in the scats were separated and identified. In the next step, the percentage of any food was calculated within the whole scats. According to the results in spring, the highest dry weight of food item in brown bear scats was belonging to plants. Brown bears had also used insects in the beginning of spring and continued to use different vertebrates during the spring season. According to the results, herbaceous plants in this season had the highest frequency among consumed bears (60%).Among the vertebrates consumed by bears, the hair ibex, the hair wild goat and the hair rabbit had similar incidence rates (5.17).A striking feature of this season is the presence of hair donkey in the brown bear consumable food that was obtained through carcasses or hunting. The results of this study revealed that Brown bears in the Golestan National Park had a variety of food sources and so that could improve their population while human activities did not destroy the habitat of this animal.

Brown Bear is the country's largest species in carnivorous which is distributed in a wide range of Alborz and Zagros mountains. Its distribution range in the western part of the country reaches Lorestan province. Sephid-Koh protected area with its vegetation, its breadth and ecological condition has created a good habitat for this species. In order to identify the range of distribution and favorable habitat of this species in the mentioned area, the presence points of species were collected in spring and summer seasons of 1396. 14 effective variables in the distribution of the species were identified. After performing the multicollinearity analysis, 4 variables were omitted due to variance inflation index (VIF) more than 10 and modelling was performed by using 10 habitat variables, 10000 randomized background points and 500 iterations in MaxEnt software. The significance of variables in modeling was done using jackknife analysis. In order to obtain habitat binary map, threshold of the LPT (Lowest Presence Threshold) was used the results of the model validation showed that the model was successful in the average run (AUC = 0.85); and the habitat variables of distance from human settlements, sub roads and altitudes had the most effect on species distribution. Based on the findings, 65% of the Sephid-Koh area is suitable for the brown bear. Regarding the distribution of species in the region, this species can be considered as a health index and a key species of the Sephid-Koh region.

Brown bear has the highest distribution within all bear species and lives in Asia, North America and Europe. It is the biggest carnivore with wide distribution and aboundance in Iran, especially in mountainous area. The largest population of the species are inhabiting along the Alborz Mountains with the highest abundance in the Central Alborz Protected Area and the Golestan National Park in Mazandaran and Golestan provinces, respectively. To increase our knowledge instead of improve the conservation level of the species remained populations in protected areas and in order to be able to predict the effective factors on habitat suitability, we had a survey on this issue in Golestan, Guilan and Mazandaran Hyrcanian forests with the Maximum Entropy (MaxEnt) software. The results show that 59% of the study area is suitable for Brown bears. Moreover, Brown bears prefer the areas with high vegetation and high slope in northern aspect. According to the results, increase of annual temperature will reduce the suitability of habitats. Also, along with determining new protected areas, it should have an appropriate distance from human settlements and villages.

The brown bear populations, contrary to other mobile carnivores, exhibit a worldwide genetic structure in several mitochondrial lineages. Populations of the Middle Eastern brown bear, including Iran, are at risk of local extinction. Genetic relationships between the Iranian brown bear and others in the world are still unclear. We sequenced a 614 base pair fragment of the mtDNA control region for 50 brown bears from Iran. The Iranian brown bear presents considerable haplotype diversity (50 individuals, 22 new haplotypes). Mitochondrial sequence analyses revealed one new major mtDNA lineage within Iranian brown bears, comprising 2–3 subclades: (i) Alborz, which includes bears from the Alborz and the Arasbaran Mountains; (ii) Zagros, including individuals from south of East Azerbaijan province to the Southern Zagros Mountains (Kazeroun, Fars province); and (iii) Fars, which comprises bears living in the Southeastern Zagros Mountains (Marvdasht-Eqlid, Fars province). The results of fixation index (FST) and analysis of molecular variance (AMOVA) demonstrate significant genetic structure among the Iranian subclades. Overall, the Iranian brown bears show significant geographic structuring, in addition to the remarkable haplotype diversity.

Selection of habitat used by species that are on the edge of their distribution range is of particular importance in ecology. Fars province is Located in the southern range and distribution of brown bear in the Iran's and world. Khom Mountain area in the Arsanjan County is one of the important brown bear habitat in the Fars province. The purpose of this study was to investigate the factors affecting on habitat resources selection of local brown bear population in North margins of Bakhtegan National Park and compare the width of ecological niche with other populations in other Fars province habitats. Based on the concept of Grinnellian niche, we use 175 presence sign in 10 Arc GIS software was used to investigate the factors affecting the ecological spatial niche. Layers is used as the factors affecting the Species ecological niche that include slope, aspect, elevation and land use. Width of ecological niche space in the Khom mountain area using the Shannon-Wiener measure and benchmark Smith (FT) respectively 0.72 and 0.71 been achieved and for other habitat in Fars Province, respectively 0.79 and 0.8 Calculated. To determine significant differences between Khom Mountain area with other habitat resource selection in Fars province of t-test was used. Which showed that there was no significant difference between the two groups (P=0.487). Although significant differences in environmental factors percent slope habitats was shown but the brown bear use of environmental resources across Fars province is almost identical.