TIL that the Paraguayan war 1864-1870 led to the death of up to 69% of Paraguay's population. After the war there were only 28,746 adult men left in the country.

I live in Brazil, close to the area where the war was fought. I heard stories that, as most of the adult men died, they would paint beards on young boys faces and send them to battle, so the enemy wouldn't notice that they were fighting kids.

Does that still influence the gender distribution of the population or has it stabilised by now?

Edit: grammar