Use the timeline below to select up to 20 seconds to watch or share.
3.75s
2s
1.09s
4.1sNARRATOR: Having reached maturity, it is time for the salmon to spawn.
5.45sThus begins their 1000-mile journey back to the exact stream in which they were born.
1.8sSo how do we find our way home?
1.57sNobody knows!
3.67sExperts are unsure whether salmon navigate by memory,
5ssense of smell, or by detecting variations in Earth's magnetic field.
2.52sOkay, everybody do one of those three things.
1.25s
2.59s
5.71s
2.57sWell, this is it. Home, stream home.
3.77sNo, it isn't! I was born in the next stream up.
0.93s
1.41s
2.32sYou're from Next Stream Up? So am I!
2.87sI can tell by the magnets in my head, or whatever.
1.83sLet's go!