Mammal Characteristics and Differences

Wildlife Biodiversity (ZO350) - Class Mammalia

• Mammals are a diverse class of animals, with about 4600 living species.
• Over 600 species are threatened due to habitat loss.
• They are the most highly differentiated group in the animal kingdom.
• Mammals exhibit a wide range of sizes, shapes, and functions.
• Some examples of influenced mammals include the bumblebee bat and the Etruscan pygmy shrew.
• The smallest mammal is the Etruscan shrew (Suncus etruscus), and the largest is the blue whale (Balaenoptera musculus).

Mammal Lineage

• Marsupials are not exclusively native to Australia.
• They are also found on Melanesian islands and in the Americas (primarily opossums).
• Mammal evolution shows a progression from early therian lineages to more recent placental mammals, including monotremes.
• The geological history (Paleozoic, Mesozoic, and Cenozoic) is reflected in the evolutionary branches of mammals.
• Cynodonts, pelycosaurs, and synapsids are important groups in early mammalian lineage.
• Prototherian lineages are egg-laying mammals.
• Metatherian lineages include marsupials.
• Eutherian lineages are placental mammals.

Mammal Family Tree (North America)

• This diagram depicts the evolutionary relationships among various mammal families in North America.
• Specific families mentioned include Manatees, Odd-toed Ungulates, Even-toed Ungulates, Whales, Dolphins, Porpoises, Primates, Bats, Carnivores, Rodents, Rabbits, Hares, Pikas, Anteaters and Sloths, Armadillos, and Opossums.
• A "★" symbol denotes a species prevalent in the Prairie Provinces.

Diversity of Mammals

• Key features of mammals include size, shape, form, and function.
• The images presented depict a wide range of mammal sizes.
• Human influence on mammals is substantial and has resulted in many species being threatened due to habitat loss.

Mammals Characteristics

• Mammals are characterized by hair, horns/antlers, glands, a specialized placenta, and a highly advanced nervous system (brain).
• They are endothermic, meaning they generate their own body heat.
• Most mammals are homeothermic, maintaining a constant body temperature.
• True hibernating is a trait of some mammals.
• In biology, exceptions to rules are common.

Hoofed/Undulates Mammals

• Specific families of hoofed animals are discussed (Bovidae, Cervidae, Antilocapridae).
• Bovidae (e.g., bison, bighorn sheep) have horns, are social, and graze primarily on grass.
• Cervidae (e.g., deer, moose) have antlers, are less social, and are browsers (consuming leaves and shrubs).
• Antilocapridae (pronghorn) provide a unique comparison and have adapted dentitions suited to varied feeds.

Horns vs. Antlers

• Horns, like those of bighorn sheep, are permanent keratin structures that do not shed.
• Antlers, common in deer, are bony structures that are renewed annually.
• The physical characteristics and growth patterns differ between horns and antlers.

Bison (Bison bison)

• Bison are characterized by their large size, often tall and thin bodies.
• A shoulder hump, large head, and reddish calves distinguish bison.
• They were nearly extinct by 1900.
• Bison have two subspecies in North America.
• Wood bison and plains bison are the two key subspecies.
• Different populations and historical ranges are noted.

Mountain Goat

• Mountain goats exhibit white shaggy guard hair over a fleecy undercoat.
• They are stocky and hump-shouldered.
• Goat's have black lips, nose, eyes and hooves.
• Short tails and long ears are common characteristics.
• Both sexes have narrow black horns.
• Billy goats' horns are thicker and curve backward in a constant arc (compared to the straighter horns of nannies).

Bighorn Sheep

• Bighorn sheep are robust and have large white rump patches with bobbed tails.
• They possess white patterns on bellies, backs of legs, and muzzles.
• Ram's have thick, curled horns whereas ewes and lambs have shorter, flatter horns.
• Immature male rams have noticeably smaller horns than mature males.
• They are adept at navigating steep rocky surfaces.
• They inhabit alpine valleys, particularly in summer, and migrate to lower elevations in winter.
• These animals are often prized as trophy species.
• They are considered a provincial mammal of AB.
• Males of this species engage in courtship battles during specific seasons.

Pronghorn (American Antelope)

• Pronghorns have a tan back and white belly and rump.
• Have white stripes on their neck.
• Both sexes have pronged horns, but female horns are shorter than males'.
• Bucks (males) have a characteristic black cheek patch.
• Pronghorn horns have distinctive characteristics which set them apart.
• They are endemic to North America.
• Their numbers were significantly reduced after the first rangelands were fenced by settlers.
• Populations are now regulated by winterkills.
• They are hunted only when populations can sustain harvests

Deer Family

• Deer are found on most continents except Australia, New Zealand, and most of Africa.
• All male deer typically have antlers (with some exceptions).
• Males are often larger than females (around 25%).
• Deer are commonly found in various habitats.
• Populations have been affected by hunting and habitat changes worldwide.

Wapiti (North American Elk)

• Wapiti are golden-brown in summer and greyish-brown with longer hairs in winter.
• Their heads, necks, and legs are dark-brown year-round.
• They have large yellow-orange/white rump patches and stubby tails.
• Bulls are known for their dark brown throat manes and distinctive antlers, which start growing in the second year.
• Cows give birth to calves away from the herd in spring.
• Bulls have a distinctive bugle sound.
• Once abundant, their numbers have decreased from parts of North America, but populations are now in the Rocky Mountains (AB) and other regions.
• The species was reintroduced into Banff from Yellowstones in 1917 and 192

Mule Deer

• Mule deer characteristically have large ears, black-tipped thin tails, large whitish rump patches, and dark foreheads with spots near the nose.
• Their color is tan in summer and dark greyish in winter.
• They have white on throat and inside of the legs.
• Their antlers characteristically have a forked or "Y" shape.
• Mule deer exhibit more tolerance of human activity compared to other deer species.
• They are often identified for stotting or pronking, a bounding form of locomotion.

White-tailed Deer

• White-tailed deer have reddish-brown fur in summer that transitions to a greyish-brown color in winter.
• They have white bellies, throats, chins, and undersides.
• White-tailed deer are characterized by prominent white-ringed eyes and muzzle banding
• Antlers develop in the late spring and last until mid-winter.
• The main beam typically has unbranched, vertically projecting tines.
• They elevate their tails when alarmed, often displaying a white rump patch.
• They are primarily found in certain regions of North America, but human impact on their range has affected these regions over time.

Moose

• Moose (elk in Europe) are the largest deer species. They have long, horse-like snouts with bulbous noses, manes along their shoulders and necks (especially pronounced in winter). Their long legs are grey to white.
• They have large bell- or dewlap-like structures hanging from their throats.
• Palmate antlers emerge laterally.
• Most of their diet (about 80%) consists of woody materials.
• They can dive underwater for extended periods closing their nostrils.

Caribou (Reindeer)

• Caribou are chocolate brown, except for their neck and rump.

• They have short, stocky bodies that help in conserving body heat.

• Long legs facilitate movement through snow.

• Their winter coats are notably dense.

• Their hooves are large, concave structures that splay widely to provide support on snowy or muskeg surfaces.

• Caribou females usually also have antlers.

• They consume lichens as a primary winter food source.

• Woodland and mountain caribou are vulnerable species in parts of AB.

• There are numerous sub-species, protected areas, and re-introduction details for several mammal species.

Test your knowledge on the unique features of mammals, including their structures, families, and common misconceptions. This quiz covers key differences between horns and antlers and explores the major distinctions between grazing and browsing mammals.