Comparing Maps
Be Careful About What They "Tell" You!

From these maps, can we assume that there are more robins in areas with lots of people? Hmmm. Good scientists always question their data and how it was collected. And they're careful about interpreting what they see.

The first map shows where Journey North observers have reported seeing robins. >>
The second map shows what parts of the country have more people than others. >>

Possible explanation
Maybe the map shows more triangles where a lot of people are located because there are more people there to notice and report robins. (There may not be more robins, just more people reporting them!)

Journaling Question

• What other factors do you think could affect where spring robins are sighted?