In the forests of northern Finland, nocturnal animals have to cope with the 24-hour day shift.
在芬兰北部的森林里，夜行动物不得不应付24小时的白班。
The flying squirrel is a rare sight.
鼯鼠并不常见。
It only breeds in this time of year.
它们只在这个季节繁殖。
In spring, this female signals she's ready to mate by marking a branch.
春天，这只雌鼠在树枝上留痕迹暗示它可以交配了。
She rubs into the bark a mixture of her own droppings chewed up with saliva.
它咀嚼自己的粪便使其和唾液混合并涂抹进树皮。
All she has to do is wait.
剩下的只要等待就可以了。
Within minutes, a male homes in on her scent by air.
几分钟之后一只雄性追踪到它的气味从空中飞来。
Flying squirrels stretch the skin between their front and back legs to create a maneuverable wing.
鼯鼠将前后肢之间的皮肤伸展开来就成了易操作的翅膀。
But another male sneaks in from below.
然而有另外一只雄性从下面溜过来。

She's worth fighting for.
它值得一博。
Falling with style, the first male lands right to the female's door.
降落颇有风格，第一只雄性正好落在雌性的门口。
Now it's up to her to make a choice.
现在，就看它选谁了。
And finally, she does.
终于，它决定了。
But love should not be entirely blind.
但是不能因为爱就无视危险。
They need to watch out for the normally nocturnal Great Grey Owl.
应该当心通常夜间行动的乌林鸮。
Hunting almost entirely by sound, owls eavesdrop on the scurrying in the undergrowth.
猫头鹰几乎全靠声音捕猎，它们留心倾听灌木丛下的动静。
Luckily for the squirrels, the owl's main prey is voles.
松鼠们很幸运，因为猫头鹰的主要猎物是田鼠。