Tsavo, Kenya has been known for a few things. First is the 1898 maneating frenzy by two lions (made infamous in the movie "The Ghost and the Darkness") and second are the maneless lions.
Unlike the beasts acting in the movie, the killing pair were maneless lions themselves, and originally scientists assumed they were unique outcasts, kept from prides and unable to find mates because of this emasculating lack of mane.
But new research into the Tsavo region shows that, far from being either uncommon or unsucessful, maneless males both seem to thrive and get the girls, garnering bigger prides of ladies than their maned Serengeti, and kept them alone.
Maneless males also tended to band together into larger fraternal groups or all male bands, sometimes numbering four, five animals or more animals.
Scientists are unsure of the reasons for these social differences in the Tsavo lions, and whether or not the lack of mane contributes, but maneless seems to be the more sucessful type of lion in this region.