Research conducted on 429 species of mammals shows that in many cases males are the same size as females and sometimes are even larger. The results are published in Nature Communications by researchers at Princeton University in the United States.
The size of males and females can vary in different mammal species in relation to the competition for mating and the investment made in the offspring. It happens for example in lions and baboons, where the males (larger than the females) physically challenge each other to win a mate.