Are Bears Mammals?
Bears are mammals. Bears, regardless of their type, are classified as mammals by the nature of several classifying features.
- Class: Mammal
- Order: Carnivora
- Family: Ursidae
Definition and Classification of Mammals
There are some exceptional animals that are classified as mammals despite not meeting certain criteria, but bears meet all of them. Mammals are known for having sweat glands—specifically mammary glands, specialized teeth, hair, endothermy (or the ability to regulate their own temperature), a unique neocortex portion of the brain, red blood cells without nuclei, and a heart with four chambers. In addition, certain mammalian bones are used in classification, like the bones that meet to form the jaw and the three tiny bones known as the malleus, the incus, and the stapes, which form the middle ear. When asked if any animal is a mammal, it is necessary to understand that the definition extends beyond what is commonly thought of as just being warm-blooded or mammalian mothers nursing their young.
Mammal Orders
Mammals are further broken down into 19 different orders. Humans belong to the order of primates. Bears belong to the order Carnivora (meat-eaters).
- Order Artiodactyla (even-toed hoofed animals)
- Order Cetacea (whales and porpoises)
- Order Carnivora (meat-eaters) – Bears
- Order Chiroptera (bats)
- Order Dermoptera (colugos or flying lemurs)
- Order Edentata (toothless mammals)
- Order Hyracoidea (hyraxes, dassies)
- Order Insectivora (insect-eaters)
- Order Lagomorpha (pikas, hares, and rabbits)
- Order Marsupialia (pouched animals)
- Order Monotremata (egg-laying mammals)
- Order Perissodactyla (odd-toed hoofed animals)
- Order Pholidata
- Order Pinnipedia (seals and walruses)
- Order Primates (primates)
- Order Proboscidea (elephants)
- Order Rodentia (gnawing mammals)
- Order Sirenia (dugongs and manatees)
- Order Tubulidentata (aardvarks)
Carnivora Families
- Canidae (dogs and related species)
- Felidae (cats)
- Herpestidae (mongooses)
- Hyeanidae (hyenas)
- Mephitidae (skunks, stink badgers)
- Mustelidae (weasels, badgers, otters, and related species)
- Odobenidae (walrus)
- Otariidae (sea lions, fur seals)
- Phocidae (true seals)
- Procyonidae (raccoons and related species)
- Ursidae (bears)
- Viverridae (civets, genets, and related species)
Ursidae Subfamilies
- Ailuropodinae (panda bears)
- Tremarctinae (short-faced bears)
- Ursinae (sun bears, sloth bears, American black bears, brown bears, Asian black bears, and polar bears)
Placental Mammals
The animals that we commonly think of as bears are not necessarily all related in the same ways, but all are placental mammals. When a placental mammal becomes impregnated, the fetus is surrounded by a placenta that nourishes the fetus and removes waste until the fetus is fully developed and ready to be birthed.
The Koala Is Not a Bear
Though there are many subspecies of bears, the koala is not one of them. The koala, often incorrectly called a koala bear, is a marsupial. Marsupials are members of the mammalian class Marsupialia, whose members are not fully developed when they are born and carried in a pouch and suckled on the mother’s stomach. The koala is closely related to kangaroos, wombats, and possums.
Resources
- Rowe, Timothy. “Definition, Diagnosis, and Origin of Mammalia.” Journal of Vertebrate Paleontology. 1988. 8(3): 241-264
- University of Colorado Boulder – “19 Orders of Mammals”
- Encyclopedia Britannica – “Carnivore – Mammal Order”
- Bucknell University – “Mammal Species of the World – Ursidae.”
- Encyclopedia Britannica – “Placental Mammal”
- Asher, R.; Horovitz, I.; Sánchez-Villagra, M. (2004). “First combined cladistic analysis of marsupial mammal interrelationships”. Molecular Phylogenetics and Evolution. 33 (1): 240–50.
