What's so different between "down" and "feather"?
The "down" feathers of a bird are usually underneath the outer layer of feathers and are much softer and warmer. Since they are so warm, these are the feathers that people often use in coats, pillows, and bedding. When birds are young, down feathers are usually the only feathers they have until they grow older and develop a new layer of stronger feathers. In the video, they refer to the feathers as "down" because the young penguin chick only has these down feathers and has not yet grown the outer layer of feathers.
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