and the grass here can support herds all year round. 能够全年维系所有的动物群落的食物需要

141. And a century ago, the bison were reduced to barely 1,000.
     一百年前 野牛的数量曾锐减至不到一千
142. Now, thanks to rigorous protection, the species is recovering.
     如今 幸亏制定了严厉的保护 这一物种的数量才得以逐步恢复
143. The growing season is long,
     这里的草儿生长期很长
144. and the grass here can support herds all year round.
     能够全年维系所有的动物群落的食物需要
145. Male bison weigh in at one ton.
     公野牛重达一吨
146. In high summer, the bulls are fat from the rich grazing
     在盛夏 公野牛个个吃得胖乎乎的
147. and in prime condition, but only a few will mate.
     精神焕发.然而只有为数不多的公牛会和母牛交配

来自《行星地球 第一季 第七集 Planet Earth S01E07 伟大草原》第 144 行