system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can communities where polygamy is common, have a large enough quantity of females when the the boy to girl ratio is around 1:1 ?

I have mostly Fundamentalist Church of Latter Day Saints and Muslim communities in my head but i know that there are plenty more that have polygamy as a part of their culture/tradition.
gpt
These communities typically fall into one of two categories:

1) Males tend to have higher death rates than females, likely due to active armed conflict with another group

2) Most males, for one reason or another, are socially ostracized and kicked out at a young age, leaving more women than men remaining in the community.