26.2: Birds (Aves)
• Birds evolved from reptiles, but still have reptilian characteristics.
• They lay amniotic eggs and have scales on their legs and feet.
• Only birds have feathers … contour feathers on the outside and soft down feathers underneath for insulation.
• Birds can fly due to: a lightweight skeleton, endothermy, and feathers.
• The feet and beak of birds helps determine which order they belong to.
• Birds are divided into 28 orders.  Some of them are as follows.
    Passeriformes – sparrows, robins, crows (5276 species); songbirds, perching feet, good vocal ability
    Apodiformes - hummingbirds, swifts (428 species); small with rapid wing beats
    Piciformes – woodpeckers, toucans (383 species); chisel-like beaks
    Psittaciformes – parrots, cockatoos (340 species); poweful beaks, very good vocal ability
    Charadriiformes - gulls, terns, sandpipers (331 species); shorebirds
    Columbiformes – pigeons, doves (303 species); stout bodies, perching feet
    Falconiformes – hawks, eagles, falcons (288 species); birds of prey
    Galliformes – chickens, quail, pheasants (268 species); limited flying ability
    Gruiformes - rails, coots, cranes (209 species); marsh dwellers
    Anseriformes – ducks, geese, swans (150 species); web-toed waterfowl
    Ciconiiformes - storks, herons, ibises (150 species); long-legged waders
    Strigiformes – owls (146 species); nocturnal birds of prey, large eyes
    Procellariiformes - albatrosses, petrels (104 species); sea birds
    Sphenisciformes – penguins (18 species); flightless, marine
    Dinornithiformes - kiwis (2 species); flightless, only found in New Zealand
    Struthioniformes – ostrich (only 1 species); large, flightless, with only 2 toes

26.3: Introduction to Mammals (Mammalia)
• Mammals evolved at the same time as dinosaurs.
• Mammals have hair and mammary glands (to make milk for offspring)
• Mammals are endothermic, so they can generate their own heat and live in colder environments.
• There are 3 groups of mammals (in 17 orders).
    Order Monotremata – lay eggs; only 6 species: the platypus, 5 species of echidna
    Order Marsupialia – have a pouch outside the mother’s body where the young finish developing; 280 species, ex. kangaroos, opossums, koalas
    Placental mammals – offspring complete development inside the mother’s body; composed of 15 different orders
• Some of the placental mammal orders are as follows:
    Rodentia – mice, rats, squirrels, porcupines (1814 species); chisel-like insicors
    Chiroptera – bats (986 species); only flying mammals
    Insectivora - shrews, moles, hedgehogs (390 species); usually nocturnal; eat insects
    Carnivora – dogs, cats, bears (240 species); land predators; none in Australia
    Primates – humans, apes, monkeys (233 species); most advanced animals
    Artiodactyla – cattle, deer, pigs, giraffes (211 species); hoofed with 2 or 4 toes
    Cetacea – whales, dolphins (79 species); aquatic, almost hairless
    Lagomorpha – rabbits, hares (69 species); rodentlike, adapted for jumping
    Pinnipedia – seals, walruses (34 species); limbs modified for swimming
    Edentata - sloths, anteaters, armadillos (30 species); eat insects; most toothless
    Perissodactyla – horses, rhinoceroses, tapirs (17 species); hoofed with 1 or 3 toes
    Proboscidea – elephants (2 species); trunks and tusks

26.4: Mammalian Adaptations
• Hair is for: camouflage, sensing, defense, and insulation.
• Claws, hooves, horns, and antlers are made of keratin (which is found in your skin, hair, & nails).
• Mammals may be herbivores, carnivores, or omnivores.
• Bats (the only mammal that can fly) use sonar to navigate and find prey.