Mammals, such as dogs, cats, hamsters, ferrets and rabbits are amongst the most popular choices for pets. They provide a warmth and response to which their owners endear.
Definition:
Animals belonging to the class of vertebrates that are warm-blooded, bear live young and nurse them with milk. Mammals are also associated with the possession of hair or fur for body covering.
Distinguishing features unique to Mammals:
Production of milk in females from mammary glands
Presence of body hair or fur
The presence of three minute bones inside the ear
The presence of a Neocortex in the brain unique to mammals
The presence of a four-chambered heart
The teeth are carried only in the dentary jaw bone
Most mammals have 7 cervical vertebrae (except for the manatee and two-toed sloth which have 6, and the three toed-sloth which has 9 cervical vertebrae)
Other features include:
They are warm-blooded (Endothermic) and have a constant body temperature (Homeothermic)
Most mammals give birth to live young (monotremes lay eggs)
Flight:
Theonly mammals for which true flight has been observed are bats; mammals such as fluing squirrels and fluing lemurs are more accurately classified as `gliding` mammals. Nearly a quarter of all mammals can fly. 985 species of bats make up 23.1% of all known mammals by species.
Some Facts about Mammals:
The Blue Whale, Balaenoptera musculus, is the largest mammal living today or which has ever lived. The longest Blue Whale ever measured was a female, 33.58 m or 110ft long. The heaviest weighed over 190 tonnes.
The largest animal on land is the bull African Elephant. The largest specimen recorded stood around 3.96 m or 13ft at the shoulder and weighed over 12 tonnes.The tallest animal on the planet is a mammal - Giraffes, Giraffa camelopardalis, can be 6.1m or 20ft tall.
The smallest mammal in the world is a bat from Thailand, Kitli's Hog-nosed Bat, Craseonycteris thonglongyai, being only 2.9-3.3 cm or 1.14-1.3 inches long and weighing a mere 1.7-2 g or 0.06 - 0.07oz.
The Cheetah, Acinonyx jubatus, is the fastest animal on land, reaching speeds as fast as 96 kmh or 60 mph.
The fastest mammal in the water is the Killer Whale, Orcinus orca, which has been recorded swimming at speeds of 55.5 kmh or 34 mph.
The fasted mammal in the air is the Big Brown Bat, Eptesicus fuscus, with a recorded flight speed of 25 kmh or 15.5 mph.
The longest lived mammals are human beings, and the Fin Whale Balaenoptera physalis is believed to have a maximum life-span of 90 - 100 years.
Rhinoceroses have the thickest skin of any terrestrial mammal. The skin on their backs and flanks can be 2.5 cm or 1 inch thick.
No two Giraffes have the same pattern of spots and no two Zebras have the same pattern of stripes.
Whales and dolphins sleep one side of their brains at a time - while one side is asleep the other keeps watch for danger.
Sperm whales can stay submerged for up to two hours descending over a mile below the surface.
A female kangaroo can produce 2 different kinds of milk at the same time when she is suckling youngsters of different ages.
Anteaters are the only mammals to have no teeth.
Hippopotamuses produce special reddish oil from modified sweat glands that acts like a sun-cream to stop them getting sunburned.
