Staging HY ROSTs still need parental care

While they can catch some fish on their own by the end of the summer staging period, by then most HY ROSTs still are unlikely to be sufficiently skilled as foragers to survive their first migration to South America without further parental care. The death of the care-giving parent or a prolonged separation before the HY has become self-sustaining likely will result in the death of the HY ROST