This is the result of both female-biased birth ratios and male migration behavior.

The birth ratio in her community is the lowest in the world due to the air pollution.

That skewed male-female birth ratio about the time we were being born is catching up with us.

Still birth ratios also increase with birth order in each birth interval category.

The same logic will hold in reverse, if we planners try to simply program-in a birth ratio sparse in males.

Meanwhile, fertility rates for married women of both races declined rapidly, making the out-of-wedlock birth ratio even larger.

The remaining possibility was that it was the infection among fathers that could lead to a skewed birth ratio.

Somehow, the mothers extract relevant information from their habitat and translate it into a changed birth ratio.

The normal human birth ratio is 106 males for every 100 females.

Industrial countries are also witnessing a decline in male to female birth ratios, and we don't know why.