What are the testosterone levels of varying animals?

[Polar]

Yes, the lion's mane is an evolutionary adaptation in lions and not much of a testosterone counter. So not much can be differed in terms of testosterone between tigers and lions in terms of the mane. 

Aggression manners are also quite different in personality between species (more aggressive blue-eyed tigers and maneless lions), and aggression comparisons would only matter intra-species (more aggressive lion could have more testosterone than less aggressive one). I would even go as far  say that the Tsavo lions have greater testosterone than most other modern lions because of their greater size, greater average muscle mass, and possibly because of their higher aggression.

Some tigers, like Sumatran ones, grow a larger mane relative to their head size and are much more aggressive than their mainland counterparts. Maybe this is due to testosterone, maybe this is just a regional adaptation/reaction to negative pressures. Sumatra was in a series of economic difficulties and a giant war in the first half and 1960s of the last century, and armies usually would burn large sections of forest down to travel through them easily. This affected many of the local flora and fauna, and Sumatran tigers probably started rebelling because of this. These tigers' differences are likely regional ones. Reply