The WD - My Passport Ultra 1TB External USB 3.0 Hard Drive will work with a Mac computer running a Mac OS X operating system.You would just simply have to reformat the drive to the HFS+ Journaled file system since it comes pre-formatted with the NTFS file system. Instructions on how to reformat to the HFS+ Journaled file system can be found here http://wdc.custhelp.com/app/answers/detail/a_id/3865/
With my recient experience with WD, I think is better for you to try G Drive products, it is a litle bit more money but it is worth it! check the G-Drive Mobile USB
Video Answer:
(click on the play button to start movie)
Products from my answer
G-Technology - G-DRIVE mobile Thunderbolt USB 3.0 1000GB Silver PA - Silver
yes buy u have to buy a usb 3.0 y cable in order for it to work. the wi u is not powerful enough to handle usb 3.0 so the y cable provides 2 usb plugs for it to work.