干旱区生态环境知识资源中心

The brown bear ( Ursus arctos L.) is the most widespread bear in the world. It can be found across Europe, Asia and North America in habitats ranging from forests to dry deserts and tundra. One of the best natural habitats of brown bears ( Ursus arctos L.) in Europe are located in Bulgaria. They are situated in the mountain massifs: The Rhodopes, Balkan Mountains, Rila, Pirin, and Vitosha. The species is a strictly protected and the Nature protection act declared areas for conservation of its habitats. That is why it is important to estimate the population size of brown bears and how this population is changed in the country during the years. In this work we study the population of brown bears in the Rhodope Mountains, using statistical data received from the National monitorings which were carried out in autumn 2011 and 2012. The observed data during the National monitorings are incomplete and contains some uncertainties. Here we suggest some approaches to resolve this problem and obtain a satisfactory estimate of the brown bear population in The Rhodopes. The suggested approaches can be applied to estimate the population of the species in the other mountain massifs. (C) 2017 The Authors. Published by Elsevier B.V.