Not unless the bulk of corturnix were concentrated around the epicenters of those two bombs.
It was probably the constant conventional bombing and a general lack of food for them. Food production facilities were fair game for bombing runs and Japan was functionally blockaded with no trade by...
Apparently World War II caused a massive loss of coturnix, and our current population is based upon just a few surviving individuals.
Puts the OP’s question in a different light.
I’m guessing the concern comes from the fact that in their domesticated form they generally cannot go broody or otherwise take care of themselves in the wild?
Supposing a calamity dries up the worldwide supply of affordable, mass produced, feed, there are still wild Corturnix that will likely...