Quote Originally Posted by Urpriest View Post
Not only are they tracked separately, but it's explicitly an additional creature. Further, animal companions must be unmodified when chosen, so you have to choose it as an animal companion before choosing it as a wild cohort. Then the animal you're choosing for a wild cohort has bonus hit dice etc. The question then becomes, is it possible to gain a wild cohort with arbitrary bonus hit dice? If so, then just gaining a wild cohort with maximum advancement would be more effective, and could be done by any character.
It initially grants a separate creature from an animal companion, which is why you must dismiss both the initial creature and your current companion to gain one creature which is both.

"A 1st-level druid’s companion is completely typical for its kind except as noted below." There is nothing prohibiting you from recruiting a creature which is not typical for its kind at 2nd or higher level. That's irrelevant though, because it is completely typical for its kind when it appears, and then it gains the benefits of both wild cohort and animal companion simultaneously.