This Is Something That Never Seems to Make It Into Textbooks

I make a point of telling my students that African slaves were not just crossing the Atlantic but that there was also a large slave trade into the Muslim world, largely stopped by British imperialism  (and which was a state goal of it).  My wife and I have been watching a BBC series on the history of Africa.  The episode "Coasts and Conquest " says that about 14 million Africans were sold across the Indian Ocean.  That is more than the more generally known 12 million of the trans-Atlantic slave trade and they were going to similar jobs or as concubines (the Muslims took more females than men opposite of the Europeans). The supply mechanism was the same: Africans enslaving other Africans for sale.

One of the complaints about the transatlantic slave trade that is often used for the miserable state of Africa today was the enormous loss of young men.  However, my reading suggests that the losses of slaves were roughly the natural rate of growth for much of the slave trade period.  

In any case, the limiting factor in polygamous societies is the number of women.  The loss of men just means men need more wives.  The loss of women as on the Indian Ocean coast would be the real population bottleneck.

Is it not a little amazing how much slaves bought by Europeans gets so much attention while the even larger trade across the Indian Ocean does not?