User blog comment:BannedLagiacrus/Monster Appreciation Week: Rathalos (5th Gen)/@comment-31029678-20180512133634/@comment-5020152-20180512154310

Well, it can be determined that certain seabirds don't touch land for months at a time based on sightings of tagged birds. If a tagged bird isn't seen anywhere for a long period of time, that means it likely spends that entire time at sea, in the air. Maybe biologists in MH do the same thing with wyverns.

Or maybe there was a random Dragonseer with nothing better to do.