Why ducklings are yellow, what the evolutionary background for this? How could it help to survive?

UPDATE 

I agree with comment below,
I did remember then that ducks are wild animals too (when I asked the question I imagined domesticated ducklings as widely pictured in media), but anyway it is interesting to know why the domesticated ducklings are yellow now. What is the reason of selection drove such coloration to young ducks or yellow pigment is just a side effect?


Question: <img src="{{media url="someurl"}}"> results in broken url & wont get parsed
Answer: Try single quotes inside curly braces that would not break wysiwyg, I had same problem which get solved doing that way.

&lt;img src="{{image url='someurl'}}"&gt;