Monarch Butterfly Migration Smallest Ever Recorded

Slate:

Feeding on a weed seems like a good evolutionary bet. And for a long time, it worked well for the monarch butterfly.

The butterfly’s life cycle is exquisitely synchronized to the seasonal growth of milkweed, the only plant its larvae will eat. In a game of hopscotch, successive generations of monarchs follow the springtime emergence of milkweed from Mexico as far north as Canada. The hardy plant once flourished in grasslands, roadsides, abandoned lots, and cornfields across much of the continent. It fueled a mass migration that ended each winter with more than 60 million butterflies converging on pine forests in the Sierra Madres.

Then came Roundup.

The number of monarchs reaching Mexico has been falling for years, and it has now reached the lowest level on record. The World Wildlife Fund announced Wednesday that butterflies this winter were found in 1.7 acres across 11 sanctuaries, down from a high of 45 acres in 1996. If you want to know a main reason why, look no further than your corn chips and ethanol-spiked gasoline.

It's pretty ironic that 1996 was the largest migration recorded.  I'm pretty sure that 1997 was the first year that Roundup Ready beans were publicly available.  Or at least the first year we grew them.  As I've said before, I remember seeing milkweed everywhere as a kid, but I haven't seen any in a long time.