由於氣候變暖，美國的白尾鹿開始向北遷徙，擴散到加拿大西部的北方森林——易危馴鹿的棲息地。牠們的天敵狼，於這些地區的數量也因此增加。隨著森林中狼的數量增多，對馴鹿等其他野生動物的壓力也隨之加重，進一步威脅到馴鹿。

Due to warming climate, white-tailed deer in America are moving and expending north into the boreal forest in western Canada, where the vulnerable caribou inhabit. when the deer moved north, their predators, wolves, also increased in those areas. with more wolves in the forest, the pressure on other wildlife like caribou has increased, further threatened caribous’ population.

https://news.ok.ubc.ca/2024/04/25/deer-are-expanding-north-and-thats-not-good-for-caribou/