Evidence suggests that some of these birds might be victims of pesticides. Most of the pesticides implicated in songbird mortality have not been used in the U.S. since the 1970's. Suggest a hypothesis to explain the current decline in songbird numbers. Design an experiment that could test the hypothesis.
A few potential hypotheses to think about:
1) A large number of the pesticides banned in the U.S. in the 1970s are still used in other countries. Therefore, you could hypothesize that birds are exposed to these pesticides during the winter months, when they migrate to Central or South America.
2) A majority of the produce consumed in the U.S. is imported; many from countries that do not ban pesticides as we do in the U.S. Perhaps imported produce is acting as a source of pesticides for song birds (if they had access to this produce during shipping or ...
In this solution I suggest a number of hypotheses and related experiments/observation to explain the current decline in songbird populations as it may relate to pesticide use in the U.S. I describe how pesticides currently banned in the U.S. are still present in the U.S. environment and U.S. produce.