Mammal Facts

  • Humans feel close to mammals because they, too, are mammals, with hairy bodies, a large brain and special mammary glands for feeding milk to their young.
  • There are about 4500 species of mammals in the world (and at least 1 million insect species).
  • All mammals except the duckbilled platypus and spiny anteater give birth to live young.
  • Mammals evolved from reptiles, but are warm blooded.
  • The two main mammal groups are the marsupials (whose young develop in the mother’s pouch) and placentals.
  • All mammals have three little bones in their ears that transfer sound vibrations to the inner ear from the eardrum.
  • Mammals have a variety of teeth shapes: chisels for gnawing, long fangs for fighting and killing prey, sharp-edged slicers and flat-topped crushers.
  • The platypus and spiny anteater are egg-laying mammals called monotremes.
  • Mammals have a palate that enables them to breathe through their noses while chewing.
  • Mammals give a level of maternal care beyond that of other animals.
  • Young mammals mature more slowly than other animal young, so they are looked after for longer.
  • Some mammals are very vulnerable because of human influences such as hunting or loss of habitat. The tiger is in the ‘critically endangered’ category on the Red List of Threatened Species.
  • Cheetahs have a band of light-sensitive nerve cells across their retinas that give clear vision ahead and to the sides.
  • Desert mammals such as the long-eared kit fox find sharp hearing more useful than a keen sense of smell in the dry air.
  • Polar bears can smell seals up to 60 km away across the ice.
  • Cats have glands between their toes that leave an identifying scent when they scratch trees.
  • Blue whales and fin whales communicate by means of the loudest sounds produced by any living creature (up to 188 dB).
  • Baby wood-mice emit ultrasonic distress calls in their first 10 days to summon their mother.
  • Many nocturnal mammals have reflective areas in their eyes that help night vision.
  • Migrating whales can sense the Earth’s magnetic field, due to particles of the mineral magnetite in their bodies.
  • The exceptionally large ears of fennec foxes can detect the sound of termites chewing beneath the ground.
  • Skunks use a powerful scent weapon to deter their enemies.
  • Many mammals carry their young around with them. Some bats even go hunting with a youngster aboard.
  • Mother whales have to nudge and encourage newly born young up to the surface to take their first breath, often aided by ‘aunts’ from the same pod.
  • In wild dog packs, several females may take turns to suckle and guard all the young in the group.
  • Sperm whale offspring may suckle for up to 15 years.
  • Elephant young are born after 22 months. Several of the herd cows help the new baby to stand.
  • Mother cheetahs teach their young how to hunt by bringing small live prey back for them to practice on.
  • Elephants live in family groups of females and their young, led by a dominant female.
  • The baby baboon depends on its mother for food and transport, but is also protected from danger by certain males in the group.
  • A female big cat carries her young by holding the entire head in her mouth, in a gap behind her teeth. Young kangaroos leave the pouch at 5-11 months, but continue to stick their head in to suckle for 6 months.
  • Baby gorillas may only climb on the silverback while they still have a white rump. Many cats, large and small, start to train their young by allowing them to attack their twitching tails.