Are discoveries in science always made by scientists?

By no means. Many scientific discoveries, particularly in fields of zoology and botany rely on the discoveries and observations of local natives. Case in point; Chimpanzee activists in Tanzania tried to educate local children about the chimps in the area by showing them pictures. The kids responded in terror, saying they steal and eat babies. The kids were right, but this flew in the face of what scientists believed at the time.