Courtship is behavior that is intended to attract a mate, and for example, female birds secrete estrogen in response to the courtship of their male mates. Given these facts, what do birds secrete to attract a mate among the following options:
- Energy.
 - Energy
 - fur and fat
 - seeds
 - oxygen
 - pollen
 - Estrogen
 - acetic acid


 

       Estrogen  