Population Pyramids and Gender [View all]

I was googling around demographics and populations when I discovered https://populationpyramid.net/

The graphics are excellent and the data source is United Nation's Population Division. So apparently accurate.
As background, I offer Wikipedia's definition: https://en.wikipedia.org/wiki/Population_pyramid
And the Economist has this great overview of changing demographics: http://tinyurl.com/lu3nddj

Fascinating comparing countries, etc., etc.

The reason I'm posting this: look at Saudi Arabia, Qatar, United Arab Emirates, and Kuwait. They are quite the anomalies.
Especially when gender imbalances in China or India grab all the headlines, but those don't really register in these charts.

Of course, the Arab Oil countries have smaller populations, but what egregious imbalances. And also not true of other Arab countries like Syria, Iraq, etc. What is going on?