I just read an except of a new study in Current Biology on chinook salmon that demonstrated that juveniles without any prior migration experience can change their orientations in response to changes in magnetic fields. Their orientations are appropriate to establishing the normal limits of their marine migrations in the Pacific. You can find an abstract of the study here: http://www.cell.com/current-biology/retrieve/pii/S0960982214000189. A friend of mine at UNC Chapel Hill, Ken Lohman, has done similar research with newly hatched sea turtles; he and his lab have demonstrated that the young turtle's movements are designed first to move them into the Gulf Stream and then keep them toward the center of the Atlantic gyre. Cool stuff.