Loosen Anne E, Morehouse Andrea T, Boyce Mark S
Department of Biological Sciences University of Alberta Edmonton Alberta Canada.
Ecol Evol. 2018 Dec 18;9(1):73-89. doi: 10.1002/ece3.4617. eCollection 2019 Jan.
Global biodiversity is decreasing rapidly. Parks and protected lands, while designed to conserve wildlife, often cannot provide the habitat protection needed for wide-ranging animals such as the American black bear (). Conversely, private lands are often working landscapes (e.g., farming) that have high human footprints relative to protected lands. In southwestern Alberta, road densities are highest on private lands and black bears can be hunted year-round. On protected lands, road densities are lowest, and hunting is prohibited. On public lands under the jurisdiction of the provincial government (Crown lands), seasonal hunting is permitted. Population estimates are needed to calculate sustainable harvest levels and to monitor population trends. In our study area, there has never been a robust estimate of black bear density and spatial drivers of black bear density are poorly understood. We used non-invasive genetic sampling and indices of habitat productivity and human disturbance to estimate density and abundance for male and female black bears in 2013 and 2014 using two methods: spatially explicit capture-recapture (SECR) and resource-selection functions (RSF). Land tenure best explained spatial variation in black bear density. Black bear densities for females and males were highest on parkland and lowest on Crown lands. Sex ratios were female-biased on private lands, likely a result of lower harvests and movement of females out of areas with high male density. : Both SECR and RSF methods clearly indicate spatial structuring of black bear density, with a strong influence based on how lands are managed. Land tenure influences the distribution of available foods and risk from humans. We emphasize the need for improved harvest reporting, particularly for non-licensed hunting on private land, to estimate the extent of black bear harvest mortality.
全球生物多样性正在迅速减少。公园和保护区虽然旨在保护野生动物，但往往无法为美洲黑熊等大范围活动的动物提供所需的栖息地保护。相反，私人土地通常是从事农业等活动的生产性土地，相对于保护区而言，人类活动足迹较大。在艾伯塔省西南部，私人土地上的道路密度最高，黑熊全年都可被猎杀。在保护区，道路密度最低，且禁止狩猎。在省政府管辖的公共土地（王室土地）上，允许季节性狩猎。需要进行种群估计，以计算可持续的捕猎水平并监测种群趋势。在我们的研究区域，从未对黑熊密度进行过可靠估计，对黑熊密度的空间驱动因素也知之甚少。我们使用非侵入性基因采样以及栖息地生产力和人类干扰指数，在2013年和2014年采用两种方法估计雄性和雌性黑熊的密度和数量：空间明确捕获再捕获法（SECR）和资源选择函数法（RSF）。土地所有制最能解释黑熊密度的空间变化。雌性和雄性黑熊的密度在草原地区最高，在王室土地上最低。私人土地上的性别比例偏向雌性，这可能是由于捕猎较少以及雌性从雄性密度高的地区迁出所致。SECR和RSF方法均清楚地表明了黑熊密度的空间结构，土地管理方式对此有很大影响。土地所有制影响着可获得食物的分布以及来自人类的风险。我们强调需要改进捕猎报告，特别是关于私人土地上非法捕猎的报告，以估计黑熊捕猎死亡率的程度。
