As the southern weather turns hot and stuffy, the ducks, missing the spring breezes which they need for their breeding season, grow bored and their hormones subside. At the same time, spring is gradually spreading across the north, melting the Earth's icy veil. With natural enemies there few in number but food plentiful, one after the other the ducks and geese start to return home.
當南方逐日燠熱，少了繁殖期需要的春風煦煦，情調不足，野鴨荷爾蒙起不了作用；同時，北方卻逐日春回大地，冰消溶解，天敵少、食草豐富，雁鴨陸續返家了！