Complex sentence: The nest is a neat cup built in a tree by both adults, and the clutch is normally 4--6 eggs, which are incubated by the female for 14--16 days until hatching.
Split into simpler sentences: The nest is a neat cup built in a tree by both adults. There are normally 4--6 eggs, which are incubated by the female for 14--16 days until hatching.