Can a rooster fertililze a duck?

A morphological species is a group of organisms that have a distinctive form: for example, we can distinguish between a chicken and a duck because they have different shaped bills and the duck has webbed feet. Species have been defined in this way since well before the beginning of recorded history. Although much criticised, the concept of morphological species remains the single most widely used species concept in everyday life, and still retains an important place within the biological sciences.

So, no the interbreeding of a chicken and a duck will not produce viable eggs.