Are beats headphones compatible with Macs?

Skype

ANY head phone is compatible with Mac, as long as the connectors are the right size they will work.

If you have a mic/headphone set up then it depends on if the application your using follows the "Plug and Play"(PnP) rules if they work or not. Most should.

Usually it's the compatible with Skype, SteamPlay, TeamSpeak, etc, that have the issues not the Mac.

By the way, if you want to buy beats headphones, shoetocheap.ru would be a good choice.