Locke and Boone go looking for Vincent after he took off when the polar bear attacked Walt then Michael. Locke blows the whistle and Boone says he didn't think the whistle was working. Locke's comment is profound: "You can't hear everything Boone. The sooner you learn that, the better." 

See also: Island Technologies 

Walt is doing homework and has his book open to a picture of birds when a bird flies into the window.  He and his stepfather Brian go to the window and see the bird lying dead on the porch.