Spotted hyena females have a pseudopenis, or penile-clitoris. This makes it nearly impossible to differentiate between the sexes. It’s even possible for females to achieve erections. Their external labia are fused together and form a pseudoscrotum. As you can imagine, the act of copulation is not simple. The female must first retract her penile-clitoris into her own body. Think about turning a sock inside out. The male can only insert his penis once the female has tucked her pseudopenis inside her body. The genital structures of the female spotted hyenas win them the distinction of being the only mammalian females to copulate, urinate, and give birth through the penile-like canal. The female gestates offspring in her uterus, but also gives birth through the penile-clitoris. The birth canal is approximately 2.5cm in diameter. Females often experience severe tearing. The rate of female mortality during childbirth is abnormally high for first-time mothers. The babies can separate from the placenta, get caught in the birth canal, and die. Female spotted hyenas have androgens (hormones) in their systems. These substances are associated with dominance and social status. Testosterone levels in spotted hyena females are as high as those in males. It’s thought that high levels of testosterone are transferred to male and female offspring through the placenta. This exposes both sexes to a high level of maleness during gestation. These steroids in adult females make them extremely aggressive, much more so than their male counterparts, despite being of similar physical size. The feeding system of spotted hyenas illustrates a clear advantage for females to be dominant. Spotted hyenas converge on freshly killed prey and eat as a group. Over twenty individuals may be vying for a piece of a kill, so competition is high. A group of spotted hyenas can transform a wildebeest to mere stains on the grass in a matter of minutes. High-ranking females are the first to indulge in a kill, along with their offspring. Low-ranking females and their offspring are next on the list, finally followed by adult males. Without question, females are socially dominant to males. There are clear ecological advantages to having high levels of androgens and testosterone. The extremely masculinized genitalia of spotted hyena female could simply be an evolutionary by-product.
One of the longest standing false accusations against the spotted hyena is that they are purely scavengers. Particularly that they steal most of their food from lions. In fact studies have shown that hyenas kill 66-90% of what they eat and when it comes to the actual hunt they are extremely versatile and successful hunters. As cursorial hunters, hyenas run down their prey to exhaustion, cruising at speeds of 37 mph (60 kph) for several miles. Spotted hyenas can bring down prey many times their size, for an animal the size of a large dog, they have been recorded to kill cape buffalo and giraffes.
Female spotted hyenas have androgens (hormones) in their systems. These substances are associated with dominance and social status. Testosterone levels in spotted hyena females are as high as those in males. It’s thought that high levels of testosterone are transferred to male and female offspring through the placenta. This exposes both sexes to a high level of maleness during gestation. These steroids in adult females make them extremely aggressive, much more so than their male counterparts, despite being of similar physical size. The feeding system of spotted hyenas illustrates a clear advantage for females to be dominant. Spotted hyenas converge on freshly killed prey and eat as a group. Over twenty individuals may be vying for a piece of a kill, so competition is high. A group of spotted hyenas can transform a wildebeest to mere stains on the grass in a matter of minutes. High-ranking females are the first to indulge in a kill, along with their offspring. Low-ranking females and their offspring are next on the list, finally followed by adult males. Without question, females are socially dominant to males. There are clear ecological advantages to having high levels of androgens and testosterone. The extremely masculinized genitalia of spotted hyena female could simply be an evolutionary by-product.
