Fact 1: Mating is generally preceded by courtship.

Fact 2: Pigeons find one mate then mate for life.

Given the two facts above, answer the question "what have a period of courtship?" with the following options: 
- animals
 - sharks
 - pigeons
 - bacteria
 - fur seals
 - judges
 - h2o
 - ducks


 

   pigeons      