"In the evening just before sundown, hundreds of monarchs were spotted flying between tree tops before settling down for the night." Monarchs rest during migration at overnight roosts, and people are delighted to discover them. Mapping the locations of these roosts can reveal the monarch's main migration pathways to Mexico. This week, find out what we know about this intriguing migration behavior, and the important role citizen scientists play in gathering information.

This Week's Update Includes:

• News: People Reporting from Canada to Mexico
• The Migration: Maps and Journal Page
• Slideshow: Why do monarchs form roosts during fall migration?
• Research Question: The best monarch books for kids?

News: People Reporting Monarchs from Canada to Mexico

Maps help us visualize data. We can see things we might not otherwise notice. Take a look!

The Map of All Monarch Sightings
The purpose of the map of all monarch sightings is to show monarch distribution. During the month of August, 641 people reported monarch sightings from three countries. Their sightings help answer this question: Where were monarchs present in August 2010? According to the data reported, monarchs were present in ___ Canadian provinces, ___ U.S. states, and even ___ Mexican states. How do you think this map will change in September?

See any surprises?
Most surprising was the presence of monarchs in Mexico in August. Nobody knows whether those monarchs were early migrants from the north or monarchs that had been breeding locally. What do you think?

The Map of Overnight Roosts
The map of overnight roosts reveals information about the distribution and abundance of migrating monarchs. Roosts are places with large numbers of monarchs, so they show us where migrating monarchs are abundant. In the weeks ahead, the roost map will reveal the main migration pathway to Mexico. What does the map show right now? According to the data reported:

• Where are migrating monarchs most abundant?
• What geographic features seem to be funneling the migration? Here's a clue (spelled backwards): Eht Taerg Sekal
• What other factors could help explain why reports of monarch roosts are concentrated where they are? Clue: Eht noitacol fo elpoep.