What is the core difference between the social comfort and individual disposition of Eiders regarding humans?

Answer

They are comfortable in crowds (with their own species) but not comfortable being touched or hand-fed by strangers

A key distinction noted is that Eiders are socially comfortable in large groups of their own kind but maintain a wild disposition concerning physical interaction or feeding by unfamiliar human species.

What is the core difference between the social comfort and individual disposition of Eiders regarding humans?
behavioranimalduckeider duck