Monarchs are the only butterflies that migrate. The transcontinental migration was discovered in 1975 when Canadian-tagged monarchs were recovered in Mexico.
The 300 million North American monarchs east of the Rockies migrate in the fall to cool mountain slopes 200 miles west of Mexico City, except for a few that winter in Guatemala or Florida.
Hundreds of millions of monarchs blanket fir trees in 12 winter roosting sites covering 40 acres. Sites hold up to 50 million monarchs. Individual fir trees host 100,000 huddled in huge clusters for warmth.
Monarchs fly 3,000 miles in the fall from Canada to Mexico. Fifty-mile-wide flocks cross the Mexican border.
In the spring, females fly back just far enough to find host milkweeds, lay eggs, and die. Subsequent generations continue migrating north.
Summer generations live only a month as they migrate north. Only the fall generation migrates south and then back north, living about 8 months.
Autumn monarchs have never been to wintering grounds. They are three to five generations removed from previous migrators. Yet they navigate unerringly to the same isolated mountain slopes.
Monarchs west of the Rockies winter in California and Baja, Mexico. Cities like Santa Cruz hoist flags to celebrate butterfly arrivals.
Read the prequels in this series on Monarch Butterflies and their significance for the creation/evolution controversy:
1. Insect GPS
2. Monarch Butterflies
3. Caterpillar or Butterfly—Which Was First?
4. Monarch Caterpillars
5. Morphing Monarchs
6. Changing Chrysalis
7. Emerging Monarchs
8. Butterfly vs. Caterpillar
Read the sequel:
10. Navigating Monarchs
Soli Deo Gloria.
Subscribe – Don’t miss future blog posts!
Click the sidebar’s “SUBSCRIBE” button to follow the
Bible-Science Guy Blog. You’ll automatically receive
new posts free by email. Click SUBSCRIBE NOW!
©William T. Pelletier, Ph.D.
“contending earnestly for the faith”
“destroying speculations against the knowledge of God”
(Jude 1:3; 2 Cor 10:4)
Thursday January 28, 2010 A.D.
And Yahweh made the beasts of the earth after their kind, and the cattle after their kind, and everything that creeps on the ground after its kind; and Yahweh saw that it was good. (Genesis 1:25)