When an Osprey ( a fishing-eating hawk ) returns from fishing to its nesting area with a fish like an alewife, a pollack, or a smelt, other Osprey's will retrace its flight path in hopes of good fishing. There is seldom such a response if the first bird brings back a winter flounder. Yet ospreys feed on winter flounder just as readily as on any other fish.
Which of the following, if true, contributes most to an explanation of the fishing behavior of ospreys as it is described above ?
1.Ospreys are seldom able to catch alewives, pollack or smelt.
2.Alewives, pollack, and smelt move in schools, but winter flounder do not.
3.Winter flounder prefer shallower waters than do alewives, pollack or smelt.
4.Winter flounder and pollack exhibit protective coloration, but alewives and smelt do not.
5.Ospreys that live in nesting areas are especially successful fishers.