Types of Animals

The North American population's interest in its animals extends across most sectors of society.

Hardly a day goes by without a mention of a sport's team, and its animal mascot. Add in discussions of family pets and culinary discussions and it seems as if animals slip into discussions morning, noon and night.


Animal discussions often refer to members of the Class Mammalia, better known as mammals.

Scientists organize their thinking and research about mammals by further dividing them into orders, or groups, that share additional physical characteristics. Depending on the source used, anywhere from twenty six to twenty nine orders of mammals live on earth constituting approximately 5,500 species.

Some mammal orders are better known that others, and from a cultural perspective, some mammal orders are more revered than others.

With the exception of one or two families, most people, for example, easily recognized the carnivores, especially the larger ocean and land families such as bears, cats, seals and sealions.

Rodentia or rodents (approximately 2,200 species) and Chiorptera or bats (approximately 1,100 species) rank as the two largest mammal orders, constituting around sixty percent of all mammal species.

Proboscidea or elephants (3 species) and Sirenia or manatees (5 species) are the two smallest mammal orders.

Many of the larger animals of the world, bears, big cats, primates and elephants, for example, are endangered, with habitat loss commonly cited at the major stress factor.

Endangered species usually refers to animal and plant species that have a high risk of going extinct in the wild.

An increase in the global population, along with the habitat destruction, including a changing climate, that accompanies modern economic development, continues to stress world animal and plant life.

A variety of public and private organizations keep track on the status of potentially endangered and endangered species.

In the United States, for example, the U.S. Fish & Wildlife Service (USFWS) reports on the endangered and threatened status of animal and plant life arranged into four categories. Within those four categories the 2010 number of species considered endangered or threatened is as follows:

  • Vertebrate Animals: 379 records of mammals, birds, reptiles, amphibians, fishes
  • Invertebrate Animals: 198 records of clams, snails, insects, arachnids, crustaceans
  • Flowering Plants: 718 records
  • Non-Flowering Plants: 31 records of conifers and cycads, ferns and allies, lichens

On a global scale, the International Union for Conservation of Nature and Natural Resources (IUCN) researches and collects statistics on bidiversity and population statistics for the natural world.

Their Red List of threatened species provides facts on the status of individual species, genera and families, organized in an easy to use data base.

According to the 2009 update, "17,291 species out of the 47,677 assessed species are threatened with extinction".

When the species are grouped into defined categories, IUCN scientists estimate that all of the endangered species break down into "21 percent of all known mammals, 30 percent of all known amphibians, 12 percent of all known birds, and 28 percent of reptiles, 37 percent of freshwater fishes, 70 percent of plants, 35 percent of invertebrates".

Dealing with endangered species on a global level presents coordination difficulties, often because of cultural, economic and insitutional differences among states.

© 2009-2014 Patricia A. Michaels