مقالات انگلیسی

در حوزه خرس قهوه ای و خرسی سیاه آسیایی

Habitat suitability and connectivity for the brown bear (Ursus arctos) along the Iran-Iraq border

Kamran Almasieh authorHaydar RouhiShahram Kaboodvandpour

Abstract: Habitat loss leads to habitat fragmentation. Habitat connectivity, however, could mitigate effects of habitat fragmentation on wildlife populations. This study was carried out to assess habitat suitability and connectivity of a brown bear population located along the Iran-Iraq border in the Zagros Mountains, at the southernmost extreme of the species range. A total of 34 presences of brown bear and seven environmental variables were used for habitat modeling using MaxEnt, and connectivity among habitat patches was assessed by electrical-circuit methods using Circuitscape. Distance from villages, elevation, slope, and distance from roads were respectively the most important variables in habitat modeling of the brown bear in the study area. In total, 33 habitat patches were identified for the brown bear, which covered about 12% of the study area. Results of connectivity revealed high connectivity among habitat patches in the Iran section, whereas in the Iraq section, only low connectivity was observed in areas close to the Iran-Iraq border. Systematic monitoring is recommended to assess potential habitat patches and habitat connectivity of the brown bear in future research as a first step towards cooperative management efforts between wildlife managers of Iran and Iraq. Moreover, establishing a transboundary protected area is highly recommended along the Iran-Iraq border to provide safety and connectivity for the brown bear in this region and reduce the effect of the country border as a separating factor.

1.Environmental Sciences, Department of Nature EngineeringAgricultural Sciences and Natural Resources University of KhuzestanMollasaniIran

2.Department of Environmental SciencesGorgan University of Agricultural Sciences and Natural ResourcesGorganIran

3.Department of Environmental Sciences, Faculty of Natural ResourcesUniversity of KurdistanSanandajIran

Water availability limits brown bear distribution at the southern edge of its global range

Mehdi Ansari H., Arash Ghoddousi

Abstract: Large carnivores are among the most threatened species in the world because of their natural low densities and need for expansive habitats. The brown bear (Ursus arctos) is the largest carnivore in the southwestern Asia, and faces threats in much of its range from conflict with humans over shared resources and shrinkage of habitat. In this study, we surveyed for brown bear sign and scat during spring–autumn from April 2013 to November 2015 in 24 randomly selected, 25-km2 grid cells, and developed a model of potential brown bear occurrence in one of its globally southernmost distribution ranges in Iran. To better understand its conservation needs and management priorities at the landscape scale, we used a combination of field surveys to develop a Maximum Entropy (Maxent) model. The model was developed using 10 environmental and anthropogenic predictors. Potential brown bear occurrence was strongly influenced by availability of water resources (54.1%) as the most important variable; and distance to roads (16.1%), aspect (7.6%), and vegetation types (5.9%) were the other important factors. The model showed an area of 581 km2 (35%) within the study area has high to good bear-occurrence probability values; 86% of this area is located in 2 patches, each larger than the average bear home range. Identification of these patches may support establishment of a reserve in the area, which would ensure long-term survival of the brown bear and sustainable water use and resource extraction from Pistacia atlantica forests by resident and nomadic communities in the region.

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