Unlike wild birds, domestic chickens lay and incubate many unfertilized eggs throughout the year. Because they are unfertilized, they will never hatch. If left under the hen, the egg will rot and despoil the nest and the hen may abandon the nest altogether. Wild birds lay only a few unfertilized eggs during mating season and incubate them along with their fertilized eggs. When the brood takes flight, the nest is often abandoned along with the unfertilized eggs, Sometimes, as in the case of Eagles and Ospreys, the couple return to the nest the following year and all traces of the eggs are gone, usually due to predators or weather.