They all lay eggs, with some species laying very large clutches.
Incubation takes around 16 days but may be closer to three weeks for large clutches; it is generally done only by the female.
The clutch is six to eight eggs but larger clutches have been noted.
However, if food resources were abundant during the breeding season, and everything else stayed constant, raising a larger clutch would be possible.
However, because of their large clutches, they can recover quickly.
They typically produce large clutches consisting of many small eggs.
The hole-nesting species tend to lay larger clutches, with an average of eight eggs, rather than just two to five.
The secondary female birds in their study raised larger clutches than primary females.
However, with such a large clutch it is difficult for her to maintain all her eggs at exactly the same temperature.
Typical clutch size for the species is 150-300 eggs, though larger clutches up to 500 have been reported.