Russian перепел ‘quail’ by origin is an onomatopoetic form through the reduplication step: *pelpel (see Russian dialect word пелепел). The problem is how this onomatopoeia appeared. We find in Yu. Pokorny: the Indo-European root *pel- ‘to fly, flutter, tremble, swim, etc.’ goes back to the Balto-Slavic words for quail – Lithuanian piepala, Latvian paipala, czech přepel, křepel and others. Čeněk Šercl, citing examples from different languages of the world, writes: "The names of quail are often expressed through an onomatopoetic representation of a quail’s scream [...]" /see Latvian putpe̹lava, puspe̹lē̹da, puspe̹lava, purpe̹lava, Lithuanian putpela ‘quail’/. Thus, by what attribute is the quail called: by its special cry or the sound produced by the wings of the bird? Historically, only the fact that the quail is вавакает ‘screams as a quail’, or, as the Germans say, schlägt, is recorded. Of course, it may appear that the meaning of ‘to hit, to hit with wings’ is simply not reflected in the ancient manuscripts. However, such an abstract semantic concept, which, for example, shows the dictionary of Yu. Pokorny is still alarming. The possibility of a later development of the meaning of ‘schlägt’ in перепел cannot be ruled out. This is probably because the *pelpel has two meanings: ‘butterfly’ and ‘quail’ (see Slovak prepelica ‘quail’ and ‘butterfly’). Perhaps бабочка goes back to the root *pelpel and is called "to hit with wings", and перепел through a step of early meaning (‘to hit with wings’), which is harder to prove, later gets a new motivation (‘schlägt’).