University of Alberta grizzly bear research and mitigation project

在北美，大型食肉动物的保护难题的缩影是标志性的灰熊逐渐灭绝。它曾经是一种草原物种，分布在美洲大陆西半部分的大部分地区，现在它的活动范围仅限于美国和加拿大北部几个偏远山区的几个小块。在过去的200年里，数十个后退的亚种群在与邻近种群隔绝后消失了。这种模式可能发生在班夫和约霍国家公园，那里的灰熊在北美的种群密度、身体质量和繁殖率都是最低的。尽管受到保护，免受狩猎和道路死亡的影响，但这一地区的熊面临着栖息地生产力低以及最近加拿大太平洋铁路(CPR)维护的火车轨道上高死亡率的挑战。2011年，四只灰熊在研究区域被杀，这是该地区经历过的铁路和公路死亡人数最多的一年，2012年又有两只灰熊被杀。熊的急剧上升和持续死亡的原因尚不清楚，但不可避免地涉及众多和相互作用的生物、地理和社会因素。

In North America, the conservation conundrum of large carnivores is epitomized by the gradual extirpation of the iconic grizzly bear. Once a prairie species that spread over much of the western half of the continent, its range is now restricted to a few small pockets in remote, mountainous areas of a few northern US and Canada. In the past 200 years, dozens of receding sub-populations have winked out of existence after being isolated from adjacent populations. This pattern could occur in Banff and Yoho National Parks where grizzly bears exhibit some of the lowest population densities, body masses, and reproductive rates in North America. Despite protection from hunting and road mortality, bears in this area are challenged by low habitat productivity and, recently, high mortality on the train tracks maintained by the Canadian Pacific Railway (CPR). Four grizzly bears were killed in the study area in 2011, the highest single rail and road-kill year the area has experienced, and two more were killed in 2012. The reasons for the sharp rise and continuing mortality of bears are not yet understood, but inevitably involve numerous and interacting biological, geographical, and societal factors.