2 sentences

1. 这只雌鸟正在巢里孵蛋。

   zhè zhī cí niǎo zhèng​zài cháo lǐ fū​dàn.

   The female bird is brooding eggs in the nest.

   Source: Dong Chinese Dictionary

2. 雌雄配合后，便会开始筑巢。

   cí xióng pèi​hé hòu, biàn huì kāi​shǐ zhù​cháo.

   After mating, the pair will begin to build a nest.

   Source: Dong Chinese Dictionary