Fact: There have now been 76 roosts reported so far this fall. Last year there had been 159 roosts reported by October 2nd.

Predict: Do you think there will be a smaller number of monarchs in Mexico this winter than last winter? Give reasons for your prediction.

Look at More Data: This chart shows how many roosts were reported to the Journey North database in past years as of October 2nd. Record the size of the winter population each year from the graph.

Year	Number of Roosts (as of October 2nd)	Size of Winter Population	Click here to see a larger graph
2008	76	(We'll find out in December!)
2007	159	4.61
2006	105	6.67
2005	129	5.92

Predict again!
Now what is your hypothesis? Based on data from the last four years, do you think there will be a smaller number of monarchs this winter in Mexico compared to last year? Give reasons to explain your thinking

Challenge: What questions will scientists be asking as they watch this season's migration? Work with a partner to write possible questions on the back of this sheet. What questions do you have? Add them to the list!