The vervet monkey (Chlorocebus pygerythrus), also widely publicized as "the blue egg monkey", is a primate native to Africa with a different characteristic. In nature, it is common to find males with striking features to attract females during the mating season. In this species, monkeys have blue testicles, in contrast to the red reproductive organ. This color is stronger in the alpha male and is becoming weaker in the other males of the species. In this way, females are able to identify the most dominant partner in the group. Among other characteristics, these animals have white tufts of fur on the sides of the face. These vegetarian monkeys have a black face and gray body hair, up to 50 cm long for males and 40 cm for females.