How does "migrating birds have lost the south" fit into this song? Some time ago, I bumped into this song called 有一种爱叫做放手. Full lyrics with translation below. Any comments are welcome. What I was wondering is: at a certain point near the start, after an if-clause and a question, we have the line:


  候鸟失去了南方 | Migrating birds have lost the south.


All I can tell about this sentence is that it means these migrating birds can no longer find their way on their migrations. How is this linked to the rest of the song? I mean, it starts off talking about how the girl has grown tired of the affair with the singer, then it goes on talking about that, and saying they should split up, and in the middle, this bird line. Sounds totally disconnected from the rest of the song to me… is it really? Also, should I interpret it as a question despite the absence of the interrogative particle 吗?

如果两个人的天堂 | If the heaven of us two
像是温馨的墙 | Like a warm wall
囚禁你的梦想 | Is imprisoning your dreams,
幸福是否像是一扇铁窗 | Has happiness become like a barred window (i.e. a prison)?
候鸟失去了南方 | The migrating birds have lost the south.

如果你对天空向往 | If you long for the sky,
渴望一双翅膀 | Crave for a pair of wings
放手让你飞翔 | And splitting up would make you fly,
你的羽翼不该伴随玫瑰 | Your wings should not, like roses
听从凋谢的时光 | Follow a time of withering.

浪漫如果变成了牵绊 | If [our] romance has become a yoke,
我愿为你选择回到孤单 | I will choose to go back to solitude for you.
缠绵如果变成了锁链 | If your bond has become a chain,
抛开诺言 | [I will choose to] break my promise.

有一种爱叫做放手 | A kind of love is called splitting up,
为爱放弃天长地久 | Leaving eternity for love.
我们相守若让你付出所有 | If our protecting each other makes you lose everything,
让真爱带我走 | Let true love take me away.
有一种爱叫做放手 | A kind of love is called splitting up,
为爱结束天长地久 | Ending eternity for love.
我的离去若让你拥有所有 | If my leaving makes you have everything,
让真爱带我走 说分手 | Let true love take me away    [and make me] say we split up.

如果两个人的天堂 | If the heaven of us two
像是温馨的墙 | Like a warm wall
囚禁你的梦想 | Is imprisoning your dreams,
幸福是否像是一扇铁窗 | Has happiness become like a barred window (i.e. a prison)?
候鸟失去了南方 | The migrating birds have lost the south.

如果你对天空向往 | If you long for the sky,
渴望一双翅膀 | Crave for a pair of wings
放手让你飞翔 | And splitting up would make you fly,
你的羽翼不该伴随玫瑰 | Your wings should not, like roses
听从凋谢的时光 | Follow a time of withering.

浪漫如果变成了牵绊 | If [our] romance has become a yoke,
我愿为你选择回到孤单 | I will choose to go back to solitude for you.
缠绵如果变成了锁链 | If your bond has become a chain,
抛开诺言 | [I will choose to] break my promise.

有一种爱叫做放手 | A kind of love is called splitting up,
为爱放弃天长地久 | Leaving eternity for love.
我们相守若让你付出所有 | If our protecting each other makes you lose everything,
让真爱带我走 | Let true love take me away.
有一种爱叫做放手 | A kind of love is called splitting up,
为爱结束天长地久 | Ending eternity for love.
我的离去若让你拥有所有 | If my leaving makes you have everything,
让真爱带我走 | Let true love take me away.

为了你失去你 | Losing you for you,
狠心扮演伤害你 | Heartlessly pretending to hurt you.
为了你离开你 | Leaving you for you,
永远不分的离去 | A breakup that we will never undo.

有一种爱叫做放手 | A kind of love is called splitting up,
为爱放弃天长地久 | Leaving eternity for love.
我们相守若让你付出所有 | If our protecting each other makes you lose everything,
让真爱带我走 | Let true love take me away.
有一种爱叫做放手 | A kind of love is called splitting up,
为爱结束天长地久 | Ending eternity for love.
我的离去若让你拥有所有 | If my leaving makes you have everything,
让真爱带我走 说分手 | Let true love take me away    [and make me] say we split up.


Note: the title is 有一种爱叫做放手 | Yôu yī zhông ài jiàozuò fàngshôu | A kind of love is called splitting up.
well as you can see at 如果两个人的天堂, the lyric tell us that there are a couple, 像是温馨的墙  tell us that the man/girl feel that their love like just like a wall, 囚禁你的梦想 imprison the his girlfriend / her boyfriend dream, 幸福是否像是一扇铁窗 then he begin to think, is this happiness has become a barred window that imprison the dream, 候鸟失去了南方 just like group of bird need/want to migrate to south, but they can't.

It's a very interesting metaphore, bird are usually migrate to the south when north become cold, it is something they need to do. In this song the writer illustrate that dream is something that as important as bird need to migrate. But when we has somebody that we love, somehow that love is stronger than the dream that we need to pursue. So the writer say this love just like prison that imprison us from pursue our dream.

Hope that explain your question, this is a very good song, I heard it once years ago, and what a surprise i can hear it again when i open your question.