Mammals

KNOWN SPECIES

6,615

0.28% of our world's living things are mammals

CHARACTERISTICS

  • animals with a backbone (vertebrates)
  • they produce milk for their young
  • they have bodies covered with hair

 

SIZE RANGE

Less than 2.4 inches to more than 108 feet (6 centimeters to more than 33 meters)

WHERE THEY LIVE

  • mainly on land
  • some live in oceans and fresh water
Image Credits:

Aye-aye, M. Shanley/© AMNH; caracal, © Derek Keats/CC BY 2.0; dog, © Karen Taber; green acouchi, giant panda, reticulated giraffe, warthog, John White/© California Academy of Sciences; human, © Shutterstock; orca, © Sabine Templeton/CC BY-NC.