Animal Class Fact Sheet

Mammals- are animals that have warm-blood, fur or hair, and have live babies.

All mammals have some type body hair or fur. Some marine mammals are nearly hairless, like whales and dolphins.
The longest mammal gestation is a little longer than 20 months, and belongs to the Asian Elephant.
Marsupial babies; like Kangaroos and Opossum, are born as small as a pinkie nail, and move to their mother's pouch to grow up.
There are 2 mammals in the whole world that lay eggs; the platypus, and 4 species of echidna. All live in Australia and New Guinea. These animals are very primitive mammals, sharing some physical features with birds and reptiles.

Birds- are warm-blooded, covered in feathers and lay eggs.

All birds have feathers, wings, and a beak, and stand on two legs.
Bird locomotion varies greatly; while most fly, there are many who cannot and will run or swim to travel.
Diets are different for all birds; the shape of their beak tells us what they eat. Some birds eat only seeds and berries. Some eat both insects and seeds. Birds of prey eat small mammals, other birds, or even reptiles.
Male birds are often more brightly colored than females. Females often have better camouflage, an adaptation to help protect the nest.

Reptiles- are animals that are cold-blooded, covered by scales, and mostly lay eggs.

The sex of some turtles is determined by the temperature at which the egg is incubated, with warmer temperatures producing females, cooler temperatures producing males and temperatures in the middle resulting in a mixed clutch. The situation is reversed for crocodiles, with males predominating at higher temperatures. The gender of a snake is determined by chromosomes, as it is in the case of mammals and birds.
About a fifth of all species of snakes bear live young. The pregnancy period among most of these species lasts about two or three months. Some species have more than 100 young at a time, but most bear far fewer. Locally, Garter Snakes have live babies.
Only a few species of reptiles provide care for their eggs or young. Among pythons, mud snakes, and some skinks, the female wraps her body around the eggs and protects them. A female alligator carries her newly hatched young to water in her mouth.

Amphibians- are cold-blooded, breathe air through their skin, and never have hair or scales.

Amphibians are divided into 3 major groups; salamanders, frogs and toads.
Babies hatch from eggs in water, and begin life as polliwogs or tadpoles. They have no limbs and breathe through gills, like a fish.
Hundreds of millions of years ago, amphibians became the first vertebrates to live on land.
One way to tell a frog and a toad apart: frogs have smooth, clammy skin, while toads have more-dry, bumpy skin. Both frogs and toads lay their eggs in water, but toads spend more of their time on land than do frogs.

Fish- are cold-blooded, live in water, and covered in scales.

Fish secrete a type of mucus from their skin. This slime coating is important because it provides protection against parasites and diseases, covers wounds to prevent infection and helps fish move through the water faster.
Many fish are specialists, eating very limited diets. Others will eat almost anything they can fit in their mouths. Cleaner wrasses of the coral reefs eat parasites off of other fish- they set up little cleaning stations that predators visit, and even let the tiny wrasse into their mouths to clean their teeth!
Fish breathe through gills located on the sides of their heads. Their gills take oxygen out of the water around them so they can breathe.
Fish range in size from the nearly microscopic to the great whale shark, which can exceed 60 feet long.

Source: Animal Facts and Feats, Gerald Wood