Most of them, yes. There are some that will appear with monsters, and others that won't accept you unless you successfully ride them without being thrown.

[He can't see Donnel having a problem with wrangling a bucking chocobo, though, the boy's got a gift with animals.]

Let's hope for the buried treasure option just the same. A boost to your Hero funds certainly wouldn't hurt.

[Chrom grins, and gives him a nod. If monsters do appear, Donnel won't be fighting them alone.]