Researchers investigated reasons why different species of birds begin to sing at different times of the morning. They captured a
nd examined birds of 57 species at different sites around England. They reported that there is a strong relationship between the diameter of a bird's eye and the time it starts singing in the morning: birds with larger eyes tend to start singing earlier.This is an example of:__________.
Researchers investigated reasons why different species of birds begin to sing at different times of the morning. They captured and examined birds of 57 species at different sites around England. They reported that there is a strong relationship between the diameter of a bird's eye and the time it starts singing in the morning: birds with larger eyes tend to start singing earlier.This is an example of An observational study, not an experiment.
