Sexual Dimorphism

Savannah from 1st period was wondering, how can you tell a male blue footed booby from a female? Do the females have different color feathers? (I know usually the males have brighter colored feathers.) Do they migrate? If so, where? How long do they live?

Savannah, you are right about many of the male birds being more brightly colored than the females of the same species. One theory is that the females do the selecting of the mates, so the male must look good to get the girl! Your question actually refers to what is called "sexual dimorphism." You are asking if there is sexual dimorphism in the species, meaning, is there a difference in the appearance in the males and females (size, color, etc.). Two local examples of birds with sexual dimorphism are the eastern goldfinch and northern cardinal. You will be able to give me many more examples after we do our bird study!


I look forward to hearing the answers to your questions because I am a bird watcher!