Nature published Jane Goodall's early findings on chimpanzee tool use. Her observations helped overturn the widespread belief that tool manufacture and use distinguished humans from all other animals.
At Gombe in 1960, Goodall watched a chimpanzee named David Greybeard push blades of grass into a termite mound and then bring them to his mouth. The termites clung to the grass, allowing him to “fish” for them. Goodall later saw chimpanzees strip leaves from twigs and use the stems in the same way.
Her findings were published in Nature in 1964 in a paper describing tool-using behavior in wild chimpanzees. The discovery was scientifically important because it demonstrated not only tool use but also tool modification. National Geographic later helped popularize Goodall's work, but it was Nature that carried the early scientific report. Animal Behaviour and Science are plausible-sounding alternatives, but they are not the canonical answer here.