User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-28303251-20151031052901/@comment-969093-20151107145607

Seeing as it was resolved already but I do want to make a point besides it, I will recap first. Yes, you can mount Apex Monsters without using Wystones. They are not immune, the only difference is that the body part that has to be hit to get a mount going is extremely limited to non-apex counterparts. Similar to how you will not bounce on only very specific spots.

However, seeing as BBD said Mounting is not a status effect, I do want to point something else out here. Though I cannot say Mounting is an actual Status Effect, it does share a mechanic that all Status Effects also have. An initial tolerance, tolerance increase and max tolerance.

Identical to Status Effects, Mounting a monster will increase its resistance / tolerance to it. A Rathalos could have 200 initial stun tolerance, it goes up by +100 after each succesful stun up to a maximum of 600 (is just an example, don't take these values as true).

Another thing mounting has in common with Status Ailments is different tolerance levels based on the Quest Rank (Village, Low, High, G, etc). That said, I don't know whether we should consider it a Status Effect or not. It's not affected by Status Atk Up so that one goes out of the window (hopefully with a few Konchus in case it starts feeling lonely).

I guess it's going to be all up to whatever the community decides or if capcom states their say on the matter. Is it completely relevant to be argueing about this? No, not really. I gave some information about mounting vs status effects and just hope that you guys go figure out yourselves what to do with it.

TLDR - Mounting has some of the key characteristics that are a trademark for conventional status effects. So is it one? I'd say yes, in a way at least and no because... well... I'm not entirely sure.