Which of the Following Could Be an Ultimate Explanation for the Behavior

question 60

Multiple Choice

Which of the following could be an ultimate explanation for the behavior of migration in birds?

• A) Decreasing day length in the fall influences a bird's circadian rhythm, which triggers flight behavior.
• B) Birds use a sun compass to orient as they fly south in the fall.
• C) Birds fly south in the fall because food resources are more plentiful there in the winter.
• D) none of the above