In the northeastern region of China, winter is characterized by a snow-covered period that can last up to half a year, with frigid temperatures and scarce food resources. To cope with these harsh environments, Asiatic black bears (Ursus thibetanus) hibernate during most of the winter, a period that also coincides with their breeding and early cub-rearing phase. Therefore, hibernation is crucial for the stability of populations in this region, and suitable dens are essential for successful hibernation. This study, conducted between 2015 and 2019 in the Wangqing National Nature Reserve in Jilin Province, identified 24 dens sites through field surveys. Using descriptive statistics, principal component analysis (PCA), and random forest modeling, we examined den structure, microhabitat, and denning habitat to explore the factors influencing den selection and the environmental factors affecting den site choice, thereby revealing the relationship between the microhabitat, denning environment, and den selection. We found that the trees selected for denning were primarily Populus cathayana, indicating a relatively narrow range of tree species compared to other studies. The denning trees had a diameter at breast height (DBH) of approximately (122. 89 ± 13. 60) cm, with den entrances measuring about (39. 26 ± 6. 62) cm in diameter. The orientation of the den entrances fell within the range of solar altitude and was sheltered from the wind, suggesting that temperature plays a significant role in den entrance selection. Entrance orientation accounted for most of the first principal component, and the DBH and entrance size constituted the second principal component. Together, these two components accounted for 0. 85 of the total variance, indicating that entrance orientation, DBH, and entrance size are the primary factors considered in den selection. The main factors influencing den site habitat selection included the distance to rivers, distance to major roads, gross primary productivity (GPP) in October, and distance to human settlements. The ecological significance of these factors suggests that the primary considerations in den site selection are safety, insulation, and access to food resources. This study provides scientific support for the conservation and restoration of denning habitats for Asiatic black bears in northeastern China.
Alt G L. 1989. Reproductive biology of female black bears and early growth and development of cubs in northeastern Pennsylvania[D]. Virginia:West Virginia University, 10-31.
Boulanger J, Stenhouse G B. 2014. The impact of roads on the demography of grizzly bears in Alberta[J]. PLoS ONE, 9:e0115535. DOI:10. 1371/journal. pone. 0115535.
Chen W C. 2017. Effects of wind speed and wind direction on net solar heat gain of south building walls in winter[D]. Master thesis.Shanghai:Donghua University, 13-30. (in Chinese)
Ciarniello L M, Boyce M S, Heard D C, Seip D R. 2005. Denning behavior and den site selection of grizzly bears along the Parsnip River, British Columbia, Canada[J]. Ursus, 16 (1):47-58.
Cui D Y, Zhang M H, Wang X M, Zhang J G, Maita K. 2011. Denning habitat selection by Asiatic black bears in the Lesser Khingan Mountains, Northeast China[J]. Sichuan Journal of Zoology, 30 (5):669-676. (in Chinese)
Cutler D R, Edwards Jr T C, Beard K H, Cutler A, Hess K T, Gibson J, Lawler J J. 2007. Random forests for classification in ecology[J]. Ecology, 88 (11):2783-2792.
Du H R. 2018. The denning habitat of Asiatic black bear (Ursus thibetanus) during winter in the Wangqing Region, Jilin Province, China[D]. Master thesis. Harbin:Northeast Forestry University, 6-9. (in Chinese)
Elfström M, Swenson J E, Ball J P. 2008. Selection of denning habitats by Scandinavian brown bears Ursus arctos[J]. Wildlife Biology, 14 (2):176-187.
Evans J S, Murphy M A, Holden Z A, Cushman S A. 2011. Modeling Species Distribution and Change Using Random Forest[M]. Berlin:Springer, 139-159.
Faure U, Domokos C, Leriche A, Cristescu B. 2020. Brown bear den characteristics and selection in eastern Transylvania, Romania[J]. Journal of Mammalogy, 101 (4):1177-1188.
Goldstein M I, Poe A J, Suring L H, Nielson R M, McDonald T L. 2010. Brown bear den habitat and winter recreation in South Central Alaska[J]. The Journal of Wildlife Management, 74 (1):35-42.
Goodrich J M, Berger J. 1994. Winter recreation and hibernating black bears Ursus americanus[J]. Biological Conservation, 67(2):105-110.
Hastie T, Tibshirani R, Friedman J H. 2009. The Elements of Statistical Learning:Data Mining, Inference, and Prediction[M]. Berlin:Springer, 587-601.
Hu Y Y, Kang X G, Zhao J H. 2009. Variable relationship between tree age and diameter at breast height for natural forests in Changbai Mountains[J]. Journal of Northeast Forestry University, 37 (11):38-42. (in Chinese)
Huygens O, Goto M, Izumiyama S, Hayashi H, Yoshida T. 2001. Denning ecology of two populations of Asiatic black bears in Nagano Prefecture, Japan[J]. Mammalia, 65 (4):417-428.
Immell D, Jackson D H, Boulay M C. 2014. Home-range size and subadult dispersal of black bears in the cascade range of western Oregon[J]. Western North American Naturalist, 74 (3):343-348.
Jansen H T, Leise T, Stenhouse G, Pigeon K, Kasworm W, Teisberg J, Radandt T, Dallmann R, Brown S, Robbins C T. 2016. The bear circadian clock doesn't'sleep'during winter dormancy[J]. Frontiers in Zoology, 13 (42):1-16.
Johnson K G, Pelton M R. 1981. Selection and availability of dens for black bears in Tennessee[J]. The Journal of Wildlife Management, 45 (1):111-119.
Judd S L, Knight R R, Blanchard B M. 1986. Denning of grizzly bears in the Yellowstone National Park area[J]. Bears:Their Biology and Management, 6:111-117.
Klenzendorf S A, Vaughan M R, Martin D D. 2002. Den-type use and fidelity of American black bears in western Virginia[J]. Ursus, 13:39-44.
Kozakai C, Yamazaki K, Nemoto Y, Nakajima A, Koike S, Kaji K. 2009. Behavioral study of free-ranging Japanese black bears II:How do bears manage in a food shortage year[C]. Kyoto:FFPRI Scientific Meeting Report, 64-66.
Kusak J, Huber D. 1998. Brown bear habitat quality in Gorski Kotar, Croatia[J]. Ursus, 10:281-291.
LeCount A L. 1983. Denning ecology of black bears in central Arizona[J]. Bears:Their Biology and Management, 5:71-78.
Li X, Yiqing M, Zhongxin G, Fuyuan L. 1994. Characteristics of dens and selection of denning habitat for bears in the South Xiaoxinganling Mountains, China[J]. Bears:Their Biology and Management, 9:357-362.
Lindzey F G, Meslow E C. 1976. Winter dormancy in black bears in southwestern Washington[J]. The Journal of Wildlife Management, 40 (3):408-415.
Lunn N J, Stirling I, Andriashek D, Richardson E. 2004. Selection of maternity dens by female polar bears in western Hudson Bay, Canada and the effects of human disturbance[J]. Polar Biology, 27:350-356.
Mitchell T M, Mitchell T M. 1997. Machine Learning[M]. New York:MIT Press.
Nielsen S E, McDermid G, Stenhouse G B, Boyce M S. 2010. Dynamic wildlife habitat models:seasonal foods and mortality risk predict occupancy-abundance and habitat selection in grizzly bears[J]. Biological Conservation, 143 (7):1623-1634.
Oli M K, Jacobson H A, Leopold B D. 1997. Denning ecology of black bears in the White River National Wildlife refuge, Arkansas[J]. The Journal of Wildlife Management, 61 (3):700-706.
Peng X X, Wu W Y, Zheng Y Y, Sun J Y, Hu T G, Wang P. 2020. Correlation analysis of land surface temperature and topographic elements in Hangzhou, China[J]. Scientific Reports, 10 (1):1-16.
Pigeon K E, Nielsen S E, Stenhouse G B, Côté S D. 2014. Den selection by grizzly bears on a managed landscape[J]. Journal of Mammalogy, 95 (3):559-571.
Pigeon K E, Côté S D, Stenhouse G B. 2016a. Assessing den selection and den characteristics of grizzly bears[J]. The Journal of Wildlife Management, 80 (5):884-893.
Pigeon K E, Stenhouse G, Côté S D. 2016b. Drivers of hibernation:linking food and weather to denning behaviour of grizzly bears[J]. Behavioral Ecology and Sociobiology, 70:1745-1754.
Rosenzweig M L. 1968. The strategy of body size in mammalian carnivores[J]. American Midland Naturalist, 80 (2):299-315.
Schoen J W, Beier L R, Lentfer J W, Johnson L J. 1987. Denning ecology of brown bears on Admiralty and Chichagof Islands[J]. Bears:Their Biology and Management, 7:293-304.
Servheen C, Klaver R. 1983. Grizzly bear dens and denning activity in the Mission and Rattlesnake Mountains, Montana[J]. Bears:Their Biology and Management, 5:201-207.
Smereka C A, Edwards M A, Pongracz J, Branigan M, Pilfold N W, Derocher A E. 2017. Den selection by barren-ground grizzly bears, Mackenzie Delta, Northwest Territories[J]. Polar Biology, 40:503-516.
Sorum M S, Joly K, Wells A G, Cameron M D, Hilderbrand G V, Gustine D D. 2019. Den-site characteristics and selection by brown bears (Ursus arctos) in the central brooks range of Alaska[J]. Ecosphere, 10 (8):e02822. DOI:10. 1002/ecs2. 2822.
Valavi R, Elith J, Lahoz-Monfort J J, Guillera-Arroita G. 2021. Modelling species presence-only data with random forests[J]. Ecography, 44 (12):1731-1742.
Vroom G W, Herrero S, Ogilvie R T. 1980. The ecology of winter den sites of grizzly bears in Banff National Park, Alberta[J]. Bears:Their Biology and Management, 4:321-330.
Wang W. 2007. Food habit, home range and habitat of Asiatic black bear (Ursus thibetanus) in the Lesser Khingan Mountains[D]. Ph. D thesis. Harbin:Northeast Forestry University, 30-34. (in Chinese)
Yamamoto T, Tamatani H, Tanaka J, Oshima G, Mura S, Koyama M. 2016. Abiotic and biotic factors affecting the denning behaviors in Asiatic black bears Ursus thibetanus[J]. Journal of Mammalogy, 97 (1):128-134.
Waller B, Belant J, Leopold B, Evans D, Young B, Simek S. 2013. Scale-dependent den-site selection by American black bears in Mississippi[J]. Mammal Study, 38 (3):211-216.
Xu L, Jiang Z W, Ma Y Q, Gao Z X. 1992. A preliminary study on the characteristics of den in the South Xiaoxinganling Mountains, China[J]. Chinese Journal of Wildlife, 67:26-29. (in Chinese)
王文. 2007. 小兴安岭林区黑熊食性、家域和生境生态学研究[D]. 哈尔滨:东北林业大学博士学位论文, 30-34.
杜海荣. 2018. 吉林汪清地区越冬熊仓生境研究[D]. 哈尔滨:东北林业大学硕士学位论文, 6-9.
陈文超. 2017. 风速风向对建筑物南墙冬季太阳辐射净得热量的影响[D]. 上海:东华大学硕士学位论文, 13-30.
胡云云, 亢新刚, 赵俊卉. 2009. 长白山地区天然林林木年龄与胸径的变动关系[J]. 东北林业大学学报, 37 (11):38-42.
徐利, 姜兆文, 马逸清, 高中信. 1992. 小兴安岭南部熊仓特征的初步研究[J]. 野生动物, 67:26-29.
崔多英, 张明海, 王小明, 张金国, 米田一彦. 2011. 小兴安岭林区黑熊对冬眠仓的选择[J]. 四川动物, 30 (5):669-676.
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