The hawks laid their first egg sometime between March 3rd and March 4th. This is right on target. Last year they dropped their first egg on March 5th. It appears that she is incubating the egg right from the start. Red tails can lay up to 4 eggs. The eggs are laid 24-48 hours apart. This means if additional eggs are laid they will hatch in hte order that they are laid with a day or two inbetween. If she waited to start incubation until all the eggs were layed, then they would all develop and hatch at the same time.