By early September, like all reindeer across the arctic tundra, Alaska's porcupine herd are entering the mating season.
到了九月初，与北极苔原上所有的驯鹿一样，格兰特驯鹿也进入了交配期。
Known as the rut, the actual mating will take place over just a few days to ensure all the calves are bornat the same time next spring.
在整个发情期中，交配活动仅仅会在几天中出现，以此保证所有的幼鹿都能在第二年舂天的同一时间出生。
At first, the herd must establish the hierarchy.
首先，鹿群必须建立它的等级制度。
Reindeer grow fresh antlers each year, under a layer of fur called velvet.
驯鹿每年都会长出新的鹿角，它被一层叫做鹿茸的绒毛所覆盖。
When fully grown, the blood supply cuts off and the male shed their velvet in preparation for battle.
当鹿角发肓完全之后，血液的供应就会停止，而公鹿就会褪去它们的鹿茸为战斗做准备。
They have the largest antlers relative to their body size of any deer species. And size matters.
它们的鹿角与体型相比是所有鹿类中最大的，而这一点很重要。
These battles may turn into a fight to the death.
这种打斗可能会变为一种生死之争。
This male's antler size and body weight give him a clear advantage.
这头公鹿的鹿角大小与体重使它具备了明显的优势。
The prize, control of up to twenty of the best breeding females and status as the dominant male of the entire herd.
而奖品则是最适于生肓的二十头母鹿的控制权以及作为整个鹿群中雄性统治者的地位。
By September, the snowy owl chicks are beginning to fledge and they're now left unattended for long periods of time.
到了九月，雪鸮幼鸟的羽翼开始逐渐丰满，父母也会留下它们很长时间不去照看。
Although armed with talons they've over two centimeters long, until they can fly, they're still vulnerable.
尽管己经具备两厘米长的爪子，它们在会飞之前还是很脆弱。
Any predators that may have wittingly wander into their nesting territory will have to deal with the adult owls who are watching from on high.
任何可能企图进入它们的巢穴所在区域的掠食者都不得不面对在高处守望的成年雪鸮。
During nesting season, the snowy owls must defend their nest against predators and are fast and powerful enough to scare off a large gray wolf.
在筑巢季节，雪鸮必须保护它们的巢穴不受掠食者侵犯，它们迅疾有力，足以吓退壮大的灰狼。
The arctic fox is no match for the owl and the young are safe for now. But in just a few days the owlets will be left entirely alone.
北极狐不是雪鸮的对手，所以幼鸟现在是安全的。不过再过几天这窝雏鸟就会被彻底地单独留下。
Before they can fly, the adult owls will abandon the nest completely.
它们还没到会飞的时候，成年雪鸮就会彻底抛弃鸟巢。
If they're to survive, the young owls will need to learn to fly before winter comes.
若想生存下来，年幼的雪鸮就得在冬季来临前学会飞行。