There may be a direct correlation between the number of great horned owl eggs and the abundance of food.
The usual number of eggs for the great horned owl is two.
Along the Atlantic seaboard this number is most frequently recorded, with three eggs uncommonly found and sets of four very rare. In Florida one egg often constitutes a full set. In central and western North America the sets appear to be definitely larger, with three and four eggs not uncommon, and five and six occasionally reported. This may be due to the more abundant food supply. Pacific horned owls tend to lay larger sets of eggs during wet than dry seasons, potentially because the birds find food more plentiful at such times.