From other games I've played.
On the tribe window it would be informative to have a tab, available to founder and administrators only perhaps, that lists activity such as -
Player 1 invited player 2
Player 3 joined the tribe
Player 4 left the tribe
Player 1 changed the tribe public message
Player 1 booted player 5 from the tribe
Player 1 set NAP with tribe B
Player 1 set tribe C as enemy
This provides a single point of reference for leadership to quickly see significant changes.