Question: One possible explanation for why some birds migrate and others maintain year round residency in a single location is intelligence. Specifically, birds with small brains, relative to their body size, are simply not smart enough to find food during the winter and must migrate to warmer climate where food is easily available (Sol, Lefebvre, & Rodriguez-Teijeiro, 2005).

Birds with bigger brains, on the other hand, are more creative and can find food even when the weather turns harsh. Following are hypothetical data similar to the actual research results. The numbers represent relative brain size for the individual birds in each sample.

________________________________________________________________________________Non-Migrating Short-Distance Migrants Long-Distance Migrants 18 6 4 N=18

19 7 5 EX2=2150

SS=48 SS=34 SS=16