小兴安岭林区黑熊对冬眠仓的选择

Denning Habitat Selection by Asiatic Black Bears in the Lesser Khingan Mountains,Northeast China

2002年11月至2003年4月、2003年11月至2004年3月,在东北小兴安岭林区对黑熊冬眠仓的特征和仓址选择进行了研究。采用网状排查的方法,调查熊仓111个和未被利用的树洞(26)、岩洞(12),其中树仓72个,地仓36个,明仓3个。结果表明:72个利用树仓和26个未利用树洞的坡度和灌丛盖度差异显著;坡度、灌丛盖度、仓口到地面高度、海拔、树高等因子与利用状况关联紧密;黑熊对树仓周围植被偏好利用针叶林和杂木林,回避阔叶林,对针阔叶混交林生境随机利用;对树仓的洞口有选择性,选择利用只有一个上洞口或侧口的树洞,回避有多个洞口的树洞;而对坡向、坡位、树种、枯树/活树和洞口朝向的利用无选择性。36个利用地仓和12个未利用岩洞的树高和坡度差异极显著,人为干扰距离因子差异显著,其余各项数量型因子差异不显著;树高、坡度、人为干扰距离、灌丛盖度、仓口长和海拔等因子与利用状况关联紧密。黑熊对地仓偏好利用上坡位和中坡位,回避下坡位;对地仓的洞口朝向选择利用仓口朝向阳面的地仓,回避阴面,对洞口朝向半阴半阳面的地仓随机利用。对植被类型、坡向、树种、枯树/活树和树洞/岩洞的利用无选择性。在小兴安岭南坡的带岭林区研究中还发现,当树仓、地仓被火烧过以后,将不再被黑熊利用;但是黑熊并不离开冬眠巢域,而是就地自建巢穴,利用明仓过冬。

The selection of denning habitat and den characteristics of Asiatic black bear（Ursus thibetanus） was studied in the Lesser Khingan Mountains,Heilongjiang province from November,2002 to April,2003 and November,2003 to March,2004.One hundred and forty nine dens were located and measured,including 98 tree-dens（72 used dens and 26 unused dens）,48 ground-dens（36 used dens,12 unused dens） and 3 nest-dens（2 new nests,1 old nest） on the ground.F-test indicated that the slope degree and the coverage degree of shrub were significantly different between used and unused tree-dens.The statistical parameter η-value showed that the strongest correlative factors to the tree-dens use were slope degree and coverage degree of shrub,followed by height of entrance,altitude,height of tree,distance from human disturbance,wield of room,length of room,diameter at breast height,etc.And the length of entrance,wield of entrance,and arbor density almost had no correlation with den utilization.Bonferroni confidence intervals indicated that Asiatic black bear preferred tree-dens in coniferous forest and shaw forest,avoiding tree-dens in broad-leaved forest,and used tree-dens in mixed coniferous and broadleaf stands randomly.The tree-dens with only one entrance were preferred,multi-entrance were avoided.The height of tree,slope degree and the distance from human disturbance were significantly different between used and unused ground-dens.The η-value showed that the closest correlative factors to the ground-dens were height of tree,slope degree and distance from human disturbance,followed by coverage degree of shrub,length of entrance,slope site,altitude,arbor density,etc.Bonferroni confidence intervals indicated that Asiatic black bear preferred ground-dens at higher and/or middle slope location,avoiding ground-dens at lower slope location.Asiatic black bear showed a strong preference for the entrances of ground-dens to the sun,avoiding shady entrances,and used ground-dens with half sunny-shady entrances.It showed no selection to vegetation types,slope directions,species of tree,died/live trees and wood/rock dens.By the survey in Dailing forestry,southward slope of the Lesser Khingan Mountains,we found that the Asiatic black bear constructed the nest-dens on the ground itself for hibernating when the tree-dens and ground-dens were destroyed by fire.Asiatic black bear would not go to other areas,and the reason needs to be further investigated.