Just after the ice melts on northern lakes (called ice-out) and the water temperature is between 49° and 59°F, muskies begin to spawn. In lakes where both northern pike and muskies live, muskies spawn after the northerns. A female lays between 60,000 to 100,000 eggs. In lakes with northern pike and muskies, the muskie seems to have fewer numbers of surviving fry. Two reasons are suggested. Since northerns hatch about two weeks earlier than muskies, the young northerns feed on the smaller muskie fry. Another reason is that the young muskie fry swim just below the surface of the water. They are easily seen by fish below or birds flying over the water.