A recent study conducted by Patricia Brennan successfully identified a social influencer that inhibits the genital growth of the male ruddy duck.
Brennan is a visiting lecturer of biological sciences at Mount Holyoke College. Her latest researched was reported by numerous media outlets.
The ability of ducks to regrow their genitals annually made them the perfect subject for the study. The results confirmed that the social milieu of ducks can have a profound effect on their genital growth: Dominant male ducks grow larger penises when they have mating competition.
A report about the study, which appeared in the American Ornithological Society’s journal, The Auk: Ornithological Advances, was published in National Geographic.
Brennan specializes in morphological evolution of reproductive structures, sexual conflict and post-copulatory sexual selection. Her current research includes investigating genital evolution in vertebrates, and genital and sperm traits in ducks.