Charadridae lay two to four eggs into the nest, which is usually a shallow scrape in the open ground, and incubate the clutch for 21–30 days. In species where both parents incubate the eggs, females and males vary in the way they share their incubation duties, both within and between species. In some pairs, parents exchange on the nest in the morning and in the evening so that their incubation rhythm follows 24-hour day, in others females and males exchange up to 20 times a day.