Etymology of “bonobo”

The year 1954 is given in the entry bonobo, does this concern the English word or the German one? There is an English use from 1955, though it actually was the proposed scientific genus name Bonobo, not bonobo as an English word. The German Bonobo was used in 1954 (Tratz and Heck) and already in 1939 (Heck).

Furthermore, while this is a native name of Pan paniscus according to a publication by Tratz and Heck (1954), there apparently was no such word; they may have been led astray by the town Bolobo (from which bonobos were shipped).