My boss just told me I should leave early, because she needs to talk to all the female employees alone (I'm the only guy at work out of the 12 of us, medical field).

It's fairly uncommon, but occasionally these meetings do happen, on which I'm later briefed on.

"Breaking up the chicken coop" is what she (my boss) calls it.

Is this common in workplace environments where there's a mix of male and female employees?

There seems to be occasional infighting at every majority female workplace I was a part of, so I'm wondering about your thoughts on this phenomenon.

Have you encountered these types of situations more at mixed workplaces, majority female, or majority male?