Nicknamed sea cow, this large aquatic herbivore leads a peaceful life in the warm waters of the globe. Meet the manatee, a mammal chilly who needs good temperatures to survive.
Manatee: family portrait
The manatee belongs to the order of Sirenia and to the family of Trichechidae. It exists 3 species different from manatees:
- The manatee Caribbean (Trichechus manatus) of which we can distinguish two subspecies depending on where they live:
- ManateeAmazon (Trichechus inunguis) populate the rivers of the Amazon basin;
- The West African manatee (Trichechus senegalensis) lives in the fresh waters of West Africa, from Senegal to Angola.
– The West Indian manatee (Trichechus manatus manatus) in the Caribbean Sea;
– The Florida manatee (Trichechus manatus latirostris) primarily in Everglades Park;
Manatee: a tail in the form of a paddle
The manatee is a large aquatic mammal with a rough skin gray in color – dark on the back and lighter on the ventral part – dotted with small stiff hairs. Its broad skull is characterized by a short muzzle, small spaced black eyes, and a thick upper lip topped with vibrissae. Its nostrils, located on the top of its head, allow it to breathe on the surface without coming out of the water. The pectoral fins are massive and long while its flat, rounded tail takes a shape of spatula. The manatee measures between 3 and 4 m and weighs 500 kg on average. Note that females are larger than males.
The manatee’s low-calorie menu
Although living in water, the manatee is herbivorous (non-ruminant). It is to this particular trait and its weight that the animal owes its nickname “sea cow”. The mammal feeds on about sixty species of plants floating or submerged that it grazes in underwater meadows or in watercourses: mangroves, water hyacinths, aquatic grasses and algae partly constitute its menu, to which are added the small Pisces, crustaceans and molluscs stuck to the plants it consumes. This nutrient-poor food forces manatees to swallow large amounts, up to 50 kg every day (between 8 and 15% of its body mass).
The manatee, independent and affectionate
When not busy foraging, the manatee spends several hours a day for itself. rest. For this, it remains between two waters and must rise to the surface every three to four minutes to breathe. The animal adopts a cruising speed of about 5 km / h but is able to reach 25 km / h in case of danger. Solitaires and independent, the adults only congregate in certain favorable situations or places: abundant food, hot zone in winter and breeding season. When they meet, manatees show themselves to be very sociable and it is not uncommon to see them stroking each other while rubbing each other’s muzzle or other parts of the body.
Manatee: a chilly mammal
Thewinter is a difficult time for manatees. As seen previously, the food ingested is characterized by a low energy content. These plants poor in nutrients do not provide the amount of fat sufficient to withstand the cold, the animal cannot stay very long in water displaying a temperature below 20 ° C. Thus, in the northern part of their range (along the Atlantic in the United States), they perform migrations to reach warmer areas. Annual migratory movements can take them more than 200 km from their starting point.
Late emancipation for the manatee
The manatee is an animal solitary until he meets a partner with whom he is going to be very faithful. The female reaches sexual maturity at the age of 7 and gives birth to a single offspring after a gestation period of 12 to 14 months. The newborn weighs on average 30 kg for 120 to 140 cm long. While being breastfed by its mother, the calf begins to eat aquatic plants between 1 and 3 months. The young will continue to breastfeed beyond 12 months, sometimes up to 2 years, the age of his independence. This long-term breeding allows the mother to show her offspring the feeding sites and migratory routes.
Manatee: protected but vulnerable
Manatees know a few predators. If crocodiles and alligators can attack young, all sirenians must face the sharks and orcas. Among the dangers weighing on the mammal is the hunt (now banned) which has long been the main cause of its decline. Today, the manatee is threatened by the maritime traffic (collision with boats, accidental capture in fishing nets), by the destruction of its habitat (tourist activities, coastal development) and by pollution maritime. The species – protected throughout its range – is classified vulnerable on the Red List of the International Union for the Conservation of Nature (IUCN). Its longevity is over 30 years.