The migration of the Monarch butterflies is underway!
As you know from reading the January and February report, the number of Monarch butterflies that made it to Mexico last fall was the lowest since data has been recorded in the 1970s. Then, with the storms that came through Angangueo, at least half of that tiny population was killed.
CBS News put together a nice story and set of videos on Monarch Butterflies this year: http://www.cbsnews.com/stories/2010/03/30/eveningnews/main6348230.shtml
USA Today also did a story on the Monarchs that was well done: http://www.usatoday.com/tech/science/environment/2010-03-30-Monarchs30_ST_N.htm
Now here we are as their cycle of life continues and the adults that survived are coming back north. This migrating generation, the same butterflies that left our yards seven months ago and flew 2,000 miles to the mountains outside of Mexico City, has mated and started their return flight north.
The females will lay eggs on milkweed plants as they fly north for as far as they can (generally no further than the latitude of 40N) until their little bodies finally expire by the end of April. As their young hatches, gobbles up milkweed and transforms from caterpillar to butterfly, they will continue the relay by flying further northward.
So where are they now? Well here’s a quick listing of reports I saw through March on the Monarch Watch listserv. You can also see the reports on the map to the left from Journey North (current as of this week).
The circles are sightings of migrating butterflies. The triangles represent locations where monarchs were seen over the winter, with the most significant being that one little triangle in Mexico:
March 6: sightings in the Lower Rio Grande
March 10: San Antonio, TX
March 12: Port Lavaca, TX (where milkweed plants were already healthy sprouts with some about 8″ high)
March 17: Eagles Pass, TX
March 22: Deridder, LA
March 24: Corpus Christie, TX
Planting milkweed now here in Virginia will provide the Monarchs with what they need when they get here by late May. Ask your local nursery to stock Swamp Milkweed and Butterfly Weed.