http://blogs.smithsonianmag.com/science/2013/02/salmon-swim-home-using-earths-magnetic-field-as-a-gps/ Ideas, innovations and discoveries from the world of science Tue, 21 May 2013 10:08:14 +0000 hourly 1 http://wordpress.org/?v=3.4 http://blogs.smithsonianmag.com/science/2013/02/salmon-swim-home-using-earths-magnetic-field-as-a-gps/comment-page-1/#comment-9565 James DeWitt Sun, 03 Mar 2013 20:05:49 +0000 http://blogs.smithsonianmag.com/science/?p=14823#comment-9565 How do we know that the salmon spawn in the same stream where they were hatched? Do the salmon in each stream have identifying characteristics? If the breeding populations in each stream do not mix, then I would expect to see that each stream would be home to distinct races and species. How do we know that the salmon spawn in the same stream where they were hatched? Do the salmon in each stream have identifying characteristics? If the breeding populations in each stream do not mix, then I would expect to see that each stream would be home to distinct races and species.

]]> http://blogs.smithsonianmag.com/science/2013/02/salmon-swim-home-using-earths-magnetic-field-as-a-gps/comment-page-1/#comment-8995 Lynda Berlin Tue, 12 Feb 2013 01:17:40 +0000 http://blogs.smithsonianmag.com/science/?p=14823#comment-8995 Salmon and other animals such as pigeons navigate by magnetic fields. I'm sure many other birds and insects do too. Approximately every 10,000 years, the earth switches magnetic poles (we know this because scientists can analyze magnetic particles in cooled volcanic rock). As of right now, the earth is several thousand years overdue for this event. Some observers suspect that early signs of this shift might be currently appearing in regions of the southern hemisphere. How suddenly this shift happens or what the results are is anyone's guess. Should this shift happen over a short period, even hundreds of years rather than thousands, much of our wildlife may be doomed. Salmon and other animals such as pigeons navigate by magnetic fields. I’m sure many other birds and insects do too. Approximately every 10,000 years, the earth switches magnetic poles (we know this because scientists can analyze magnetic particles in cooled volcanic rock). As of right now, the earth is several thousand years overdue for this event. Some observers suspect that early signs of this shift might be currently appearing in regions of the southern hemisphere. How suddenly this shift happens or what the results are is anyone’s guess. Should this shift happen over a short period, even hundreds of years rather than thousands, much of our wildlife may be doomed.

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