Mammals Banner

What does this page offer?

  • Read about the basic facts on mammals
  • Access some of the free short courses on mammals
  • Join OZT as a member to learn even more about how to work with mammals while meeting people from around the world!

You have chosen a career to follow and prepare for; now it’s time to learn more about the species you will work with.

  • Read about the basic facts on mammals
  • Join the Mammals Group to learn how to work with them and meet people from around the world
  • Access all of the free short courses on mammals
  • Connect with tertiary institutions and organisations that work with mammals

Basic Facts on Mammals

A warm-blooded vertebrate animal of a class that is distinguished by the possession of hair or fur, females that secrete milk for the nourishment of the young, and (typically) the birth of live young.

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Scientific name:


The word “mammal” in other languages:

  • Dutch: zoogdier
  • French: mammifère
  • Spanish: mamífero
  • Turkish: memeli

Awesome fact:

Mammals give their young survival skills

Mammals Stats

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Assumed to originate from a line that diverged away from the reptiles about 300 million years ago.

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The smallest mammal is the Kitti's hog-nosed bat with a length of about 1.1 to 1.3 inches (29 to 33 mm) and weighing less than 0.07 oz (2 g). The largest mammal is the Blue Whale at 98 feet (30 m) in length and 200 short tons (180 metric tons) or more in weight.



Lifespan ranges from a year or two in some rodents, to over 150 years for certain species of whale.



Most mammals are viviparous, giving birth to live young. However, the species of monotreme (the platypuses, marsupial moles, the echidnas and a few others) lay eggs.

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Between 12 to 13 days for the Opossum, to about 640 to 660 days (or roughly 95 weeks) for Elephants.

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Main Diet

The diets of mammals span across all three main dietary groups: herbivores, carnivores and omnivores.

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Different species of mammals have evolved to live in nearly all terrestrial and aquatic habitats on Earth. Mammals inhabit every terrestrial biome, from deserts to tropical rainforests to polar icecaps. Many species are arboreal, spending most or all of their time in the forest canopy.

Global Population

Global Population

It is estimated that the total number of wild mammals in the world is about 130 billion. The mammal with the highest population is cows, estimated at around 1.5 billion.

The scientific classification of mammals

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Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: 29 to 33
Family: 150 +
Genus: 1200 +
Species: 6400 +

Do you have facts to contribute to this page? Please click on the red beetle to access the contribution form.

Free Short Courses on Mammals

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Join one of the Mammal Groups

Learn even more about mammals by joining one or all of the MAMMAL GROUPS

Amount of Mammal Groups: 4

Learn even more about mammals and specific groups of species by joining either the general, or one of the three specialized Groups.

Members of the 4 Groups can access all the different Short Courses, specific to the kind of species in the Group, as well as win awards and meet other mammal lovers from around the world. Gain points with each short course and compete for the top spot on the leader board!

Four Groups:

  • General Mammal Group (all mammals)
  • Primates
  • Marine Mammals
  • Wild Cats

Topics covered in each of the MAMMAL GROUPS:

  • Anatomy
  • Habitat
  • Behaviour & Diet
  • Ecological Benefits & Conservation
  • Species (courses on over 300 different species)

Interact with all of the relevant tertiary institutions that feature courses related to mammals, as well as animal organisations that work with mammals.

If you are not a member yet, then register for FREE!

Career profiles and resources

How many career profiles are there on OZT where you can work with mammals?

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Indirect Contact

Contributions by expert members are always appreciated to allow the students to learn about the species they will work with. Please add your contribution through the attached form:

Contribution Form

List of Species Mentors/Educators who have contributed to the info:


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A few excellent pictures as examples of the species:

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