The troop sat at the edge of a grove, barely shielded from the mid-morning sun the shadows of the canopy. A lazy day. They would probably go to the feeding ground in anywhere from ten minutes to three hours.
Suddenly, screams filled the air. Then a wahoo. A female, lips curled back, tail in the air, and shrieking, bounded past. She was moving too quickly for me to identify her. A male ran by, and I would have mistaken him, as well, except for that brief second when he turned his head toward me as passed, never slowing. Those intense yet stoic eyes told me it could only be Aaron, the alpha.
Aaron herded this single female around for almost five minutes without a break. At the end, she could barely keep running; it was the equivalent of a human jog which was actually no quicker than a walk. Aaron slowed his pace to match, but did not catch her - he had already done so twice, and the newly opened wound on her face would mark her for a couple weeks at least.
When the chase reached this point, I realized that he seemed to have brought her full circle, back to the core of the troop. Not quite. What actually happened was that the female core (and me accompanying them) had slowly shifted in the direction of Aaron and the female he was chasing. The whole troop has moved about 30 meters in this five minutes.
This was a case where the male appeared not to be directing the movements of the troop. He was involved with this lone female for reasons not apparent to me. Meanwhile, rest of the troop moved. The most obvious reasons would be because they wanted to stay near the male for his protection. The females like to be around the adult males, the alpha in particular. They seemed drawn to him, but followed of their own choice.
However, appearences are highly suspect (and this isn't how all herding goes down). The male might know that the effect of chasing the female will be that the others will respond accordingly. The chasing of the single female could be a highly complex social signal which told all of them to "move and follow." The females would obey, the infants would follow their mothers, and the juveniles would follow their junior playmates, and the remaining guys would have barely anyone left behind to interact with, and would thus be forced to fall in line.
Does it matter if the male chases a female back towards the troop, or away from the troop's center? Are they distinct behaviors? If they followed him regardless of where he chased, it could be evidence to say they are just following the male. What if the chaser wasn't the alpha, but a different male? Males before and after their prime could yield different results. Tricky - I think looking for a behavior where aggression is not involved would be a better way to determine if the male (and which male) is perceived as the "leader."
I'm going to keep my eyes open for a clear example of when the male clearly is not purposefully directing the group. Given our inability to understand the mental states of baboons, it might not be possible for me to be certain that I've found a scenario where the male definitely isn't considering the troop (and his females as a whole) when he is making a directed movement. But, I shall make the attempt, and possibly construct a variety complementary situations.