animations lost with mb/ma files in Unity

I am experimenting with ma/mb files in Unity and it appears that the animation clips are lost, once the mb/ma file is saved/opened in Unity. I tried saving the file from Maya into Unity (save as). I tried importing file in Unity from Maya (import new asset). I tried copy\paste the file from Maya folder to Unity Assets folder. I tried selecting the root and the clips in the Animation editor in Maya before saving into Unity. I tried selecting nothing in Maya before saving into Unity.

The only way to have the animations in Unity appears to be to export the Maya file as an FBX. Is it so? no animations are saved in Unity unless the file is imported as an FBX? thanks very much for your help