- A Lion's Mane Color Reveals Its Health and Testosterone Levels: A male lion's mane isn't just for show; it acts as a biological status symbol. The darker and thicker the mane, the higher the lion's testosterone, nutrition level, and overall health. Female lions prefer males with darker manes when choosing a mate, while rival males tend to avoid picking fights with them. - Their Roar Can Be Heard 8 Kilometers Away and They Protect Their Own Hearing: A lion's roar is one of the most powerful sounds in the animal kingdom, reaching up to 114 decibels. Thanks to the unique square shape of their vocal cords, they can produce a massive sound without expending much air pressure. To protect their own eardrums from the deafening volume, they reflexively contract their middle ear muscles while roaring.