Discussion: Monarch butterfly navigation

An experimental displacement and over 50 years of tag-recoveries show that monarch butterflies are not true navigators.

TheLocal.de says, "The butterflies used natural landmarks such as the Rocky Mountains or the Gulf of Mexico to find their way. So for example if they started to the east of the Rockies, they would fly south west until sooner or later they hit the mountain barrier. Then they just fly along the Rocky Mountains or the Gulf coast in such a way that they keep as close as possible to the direction of their inner compass.

The two landmarks act like great roads leading the butterflies in the right direction, which then converge on each other in Mexico. The swarms of insects are then funnelled towards a range of volcanoes, where they are stopped in their tracks - and spend winter months, cool, but without frost."

So, to paraphrase: the butterflies aim off to a linear feature, follow the handrail to a collecting feature, and go until they hit a catching feature. Seems like a pretty good navigation strategy. Simple, and doesn't take a lot of brain power.

Interesting!

Thanks for the interesting article. But I really don't buy this glib explanation. Let's just say that Mother Nature still has many undiscovered secrets, that may forever remain beyond the ability of human brain power to understand.

Global warming is another undiscovered secret: do we really understand what we're doing to our environment, when most Americans spend every day furiously injecting carbon from deep in the ground, into the atmosphere where it will remain for many years to come?

If you are stuck on the ground like dung beetles, use the Milky Way!
"Humans, birds and seals are all known to navigate by the stars. But this could be the first example of an insect doing so."
http://www.bbc.co.uk/news/science-environment-2115...

Meanwhile on Thursday, the Hawaiian monitoring station atop Moana Loa recorded CO2 levels above 400ppm for the first time. You can't look at this graph and not feel a twinge of guilt the next time you press that accelerator.

I wonder if the monarch butterflies and dung beetles, and their mysteries, will survive to see us top 800ppm...

The level of the most important heat-trapping gas in the atmosphere, carbon dioxide, has passed a long-feared milestone, scientists reported Friday, reaching a concentration not seen on the earth for millions of years...a continuing rise could be catastrophic. It means we are quickly losing the possibility of keeping climate perturbations below what people thought were tolerable....

I feel guilty when I press on the accelerator and then hit a monarch butterfly. But I only feel that way for a moment. It's hell cleaning them off of my car's grill.

If the butterflies and beetles don't survive at 800ppm, then they didn't deserve to live anyway since they couldn't adapt to their environment. Isn't that how it works in your world?

Since I haven't bred, I'll reserve the accelerator pedal guilt.