Analyzing Loon Migration in Wisconsin
Spring, 2000

With the arrival of over 100 loon sightings from Wisconsin in one short month, you are probably as exhausted as the loons! If their migration seems like a blur, it would help to focus in on this single state, and see what can be learned from the large volume of data.

Try This!
When do you think loon migration into Wisconsin peaked this spring?

1) We've compiled all Wisconsin loon data for you (at link below). Print out the data, and count the number of sightings per day. Then make a graph to show the peak arrival. On which day did the most loons arrive?

2) Sometimes it's helpful to group data into larger categories. Try grouping the sightings on the data page into weeks. Count the number of loons that arrived each week. Then calculate the percentage that returned each week, and make a graph. (The chart below may be helpful.) During which week did the most loons arrive?

Loon Migration by Week

# Returned

% of Total

Before Mar. 19    
Mar. 19-26    
Mar. 27-Apr.2    
Apr. 3-9    
Apr. 10-16    
Apr. 17-23    
Apr. 24-30    
After Apr. 30    

3) What relationship does this spring's migration seem to have with weather? (Look for days with the most loon sightings. Then visit the weather archives and investigate the weather conditions on--and immediately before--those days. Note wind direction and speed, the location of fronts, high and low pressure areas. Also note the sky conditions, whether clear or cloudy.)

4) Why might so many loons have appeared on April 1st & 2nd? (Did you notice that 25% of the loons were reported in just two days?)

5) When did the ice go out this year in Wisconsin lakes? Was it early or late? Do you think an early or late ice-out would affect the loons' arrival dates?

6) Overall, what conclusions can you draw about loon migration based on this spring's data?