University of Alberta grizzly bear research and mitigation project

在北美，标志性的灰熊的逐渐灭绝是大型食肉动物保护难题的缩影。它们曾经是一种草原物种，分布在美洲大陆西半部的大部分地区，现在它们的活动范围仅限于美国北部和加拿大一些偏远山区的一小块地方。在过去的200年里，几十个逐渐消失的亚种群在与邻近种群隔离后消失了。这种模式可能发生在班夫和尤霍国家公园，那里的灰熊表现出北美最低的人口密度、体重和繁殖率。尽管受到了狩猎和道路死亡的保护，但该地区的熊面临着栖息地生产力低下的挑战，最近，加拿大太平洋铁路（CPR）维护的火车轨道上的熊死亡率很高。2011年，研究地区有4只灰熊被杀，这是该地区铁路和公路撞死灰熊最多的一年，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，但不可避免地涉及许多相互作用的生物、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.