especially when it comes to finding a mate. 尤其是在寻找配偶时

104. Mammals were now big enough
     哺乳动物此时已非常庞大
105. to rival the long-lost dinosaurs.
     能够与消失已久的恐龙相媲美
106. But being big has other implications...
     但庞大也有别的影响
107. especially when it comes to finding a mate.
     尤其是在寻找配偶时
108. This female is already closely guarded by a male,
     这只雌巨角犀 已经被一只雄巨角犀严密地守护着
109. much larger than the first.
     比之前那只雄巨角犀大很多
110. If challenged,
     如果受到挑战

来自《我们星球上的生命 第一季 第七集 Life on Our Planet S01E07 地球继承者》第 107 行