In winter, dove populations are at their lowest point. The birds use tall trees for roosting at night. By day, doves fly out to fields and open areas to feed. The reproductive season starts with courtship on the earliest warm days of January in the coastal plain and a little later further north. The male sits on a perch near the female and coos. The reproductive organs begin to enlarge. As spring advances, the birds linger around a suitable nesting habitat of pines, shrubs or vine tangles. Nesting begins in February in the coastal plain and is delayed about a week for each 50 to 100 miles north. The percentage of the population nesting increases rapidly as the days lengthen. Mourning doves nest in rural and suburban areas, but nests tend to be near open areas and are uncommon in the interior of dense woods. Nests may be located a few feet off the ground or near the tops of the tallest trees; most are found within 10 to 25 feet of the ground. Doves carry little sticks, pine needles, rootless and weed stems to a suitable place on a branch. They take about a week to make a flimsy nest, which is sometimes so sparse that one can see the eggs through the nest from below.