This Week's Update Includes:

• News: First Leaving, First Arriving
• Graph: Population at Record Low
• Slideshow: Spring Migration
• The Migration: Maps and Journal

"The monarchs were traveling like passengers in a train, rushing to reach an appointment somewhere," Estela reports.

Population at Record Low
Mexican officials announced on Thursday that this winter's population hit a record-low, with butterflies covering only 1.19 hectares. There were more than twice as many monarchs last year. Although insect populations fluctuate naturally, scientists are concerned about the overall downward trend the graph shows.

For the classroom:
Slideshow: How Many Monarchs this Winter?
Population Graph: 1994/1995 to 2012/2013

First Sightings!
To the delight of observers in Texas, the first monarchs are beginning to appear. When monarchs were spotted in the Mexican state of Querétaro this week, the observer shared some local lore:

"These spring monarchs are called 'planters' because they pass as we prepare to plant corn. In November we call them 'harvesters' because they pass at the time of harvest."

Fewer Sightings
Only 5 sightings have been reported so far this spring, compared to over 100 last year at this time. (See map.) With the population so small, monarchs need high quality habitat to recover their numbers. The southern United States will be critical. The next generation will be produced there during the next 4-8 weeks.