bison became the focus of another group of survivors. 野牛成为另一群幸存者的重点目标

221. ...roaming in huge numbers.
     四处游荡 数量庞大
222. But they weren't alone.
     但它们并不孤单
223. With fewer big prey to choose from,
     由于大型猎物减少
224. bison became the focus of another group of survivors.
     野牛成为另一群幸存者的重点目标
225. Age-old enemies.
     宿敌
226. Their best defense is to keep an eye on the danger,
     它们最好的防御是警惕危险
227. stick together, and calmly move on.
     聚在一起 冷静前行

来自《我们星球上的生命 第一季 第八集 Life on Our Planet S01E08 冰与火的世纪》第 224 行