北美海牛

• In the American manatee, male sexual maturity occurs at 9–10 years, but they may conceive as early as 2 years. Females reach maturity at 4–5 years.
• The American manatee uses its lip to dig up plant roots. It can also grasp leaves from almost all plants encountered along its path using its lip.
• The American manatee is born with large and small molars and can eat plant food about three weeks after birth. This happens despite being nursed by its mother for the first 18 months.
• The American manatee can reach speeds of up to 25 km/h for distances no more than 100 m. Its usual speed does not exceed 10 km/h.
• Male American manatees scratch themselves to secrete an enzyme and signal their sexual maturity to females. The enzyme is specifically released to attract nearby females.
• The upper and lower lip of the American manatee can move independently. The feeding animal grasps vegetation with its lips and moves it into the mouth, where the teeth are located.
• American manatees may migrate north if water warms to 20 °C or higher. In summer, they may move as far north as Virginia and Louisiana, with Rhode Island being the northernmost state where manatees have ever been recorded.
• The American manatee can roll, flip, and swim on its back. It uses its tail for forward movement and its flippers as a rudder.
• The American manatee requires fresh water to maintain osmotic pressure, even though it can tolerate a wide range of salinity. Without prolonged access to fresh water, animals may become dehydrated.
• The bond between a mother and calf is the only stable and long-term relationship among American manatees. This bond lasts for many years, even when the calf grows and no longer needs direct help from the mother.
• Female manatees use their flippers to push away neighbors, but males in musth behave peacefully, showing no aggression toward each other. During this period, they try to quickly approach a potential mate.