I was under impression that data about quite a lot different species using different tools is a fairly modern phenomenon, i.e., all of the research is fairly recent.
Around 50 years ago it was widely believed, by scientists too, that it was only apes that are able to use tools. I was recently told that it's basically nonsense and scientists have been studying different tool-using animals since the beginning of the 20th century or earlier.
Where could I get more info on research done in this area? I'd be especially thankful for those done in USSR, since it used to be my country and my knowledge on everything was basically limited by the Iron Curtain. However, I am also interested in research done worldwide as well.