Confidence votes 210. Antigone is considered a tragic hero, because tragic heroes have several qualities: They are royal, they have a tragic flaw that leads to their downfall, they have an unhappy ending, and lastly the character is worthy of concern. First, Antigone is royalty. This is shown through her bloodline in several ways.
The down feathers of eider ducks provide insulation due to lack of barbules and ability to fluff. Infrared image of a goose, showing its insulating capacities. Down feather structure is important for insulating properties. Eiders insulate their arctic nests with down feathers. Click/tap images for attribution and license information.
However, they found plenty of evidence to favor the idea. When the penguins are out of the water, they preen their feathers and fluff them up all over their streamlined bodies, adding about an inch of air between the skin and outermost layer of feathers. Preening also adds waterproofing oil to the feathers.