Phylum: Chordata Class: Aves (Birds)

Classification Kingdom Animalia ---Phylum Chordata ------Subphylum Vertebrata ---------Class Aves Aviation = flight

Hummingbird Order: Apodiforma

Tucan

Order: Falconiformes Peregrine falcon

Order: Galliformes

Dove

Class: Gaviiformes Loon

Penguins

Origin and Early Evolution Evidence from fossils and studies of comparative anatomy indicates that birds evolved from reptiles Their features and their fragile hollow bones do not preserve well. copyright cmassengale

Evolution of Birds (from reptiles) Archaeopteryx - “ancient wing” Reptile like - Had teeth in beak, bony tail, claws on wings Bird like = Had feathers, & fused collarbone (wishbone) Could not fly – could glide for glide short distances

Aves Characteristics 1. Forelimbs modified into wings 2. Thin layer of epidermis; No sweat glands 3. Feathers – made of keratin 4. Hollow, lightweight bones 5. Endothermic 6. Efficient respiration 7. Heart with a completely divided ventricle (4 chambers) 8. Scaled feet (birds are related to reptiles) 9. Furculum (wishbone)

Body Plan Bilateral symmetry Forelimbs modified into wings Bony skeleton with air pockets Beak, no teeth Single bone in the middle ear Endothermic

copyright cmassengale Skeleton The sternum supports the large breast muscles The humerus, ulna, and radius, along with the pectoral girdle and the sternum, support the wing. The pygostyle, the terminal vertebra of the spine, support the tail feathers, which also play an important role. copyright cmassengale

Feather Types 1. Contour feathers 2. Down feathers Has a hollow quill, main shaft, and barbs, barbules Covers, streamlines body, and allows flight; coloration 2. Down feathers Light and fluffy conserve heat (birds are endothermic) 3. Filoplume feathers Hair-like/no known function

Feathers are covered in oil to keep them water proof - "like water off a duck's back" - this oil is secreted from a preen gland Preening is a behavior that replaces the oil on feathers, and repairs broken links on the vanes

Feather Types

Feather Structure

copyright cmassengale Endothermy Generate and regulate body heat internally Enables birds to inhabit both cold and hot climate Body temperature ranges from 40- 46 degrees Celsius. To help conserve body heat, birds fluff out their feathers to insulation. copyright cmassengale

Nervous System - response Well develop sense organs A large brain Cerebrum = thinking, decision making Cerebellum = coordinated movement Medulla oblongata = basic body process Optic lobes = vision Olfactory lobes = taste and smell

Respiration Highly advanced respiration Posterior and anterior air sacs with tube in between Continuous one way flow 2 functions of the lungs Oxygenate tissue Cooling (no sweat glands)

Nutrition Carnivores Omnivores Nectar feeders There is a bird to hunt nearly every insect Omnivores Nectar feeders Have specially developed beaks to accomplish feeding task Birds can eat up to 100% of their weight in food every day

Digestion No teeth/poorly developed salivary glands Grinding occurs in the gizzard Pebbles are swallowed by the bird to help the gizzard grind the food Pharynx—Esophagus—Crop—Stomach—Gizzard—Intestines—Ceca(in herbivores only, ferments)—Rectum—Cloaca

Excretion Paired metanephridic kidneys Uric acid is formed Urine is formed by filtration Uric acid is formed Advanced animals, because it has low solubility it can be excreted with little water loss Salt glands aid in removing salt

Territoriality and Courtship During the breeding season many male birds establish an area that they defend against other males of their species, a behavior called territoriality. The male then attempts to attract a female to share this territory. Once a territory is established most birds engage in a period of courtship, behavior that is designed to attract a mate. Many males attract females by means of their brightly colored feathers. Some males combine song with flight displays. copyright cmassengale

Reproduction Sexual reproduction Monogamy is general rule in Aves flamboyant coloration to attract mate Monogamy is general rule in Aves Seasonal Lifetime—swans, geese Internal fertilization Birds lack a penis, so cloaca must meet Oviparous

Why Monogamy? Provide food, it must be gathered Need for a nest Eggs must be incubated Males are chosen because they have secured a territory Announced through song

Development Direct development Egg Juvenile—must be cared for Adult

Many baby birds are born helpless and without feathers Many baby birds are born helpless and without feathers. These baby birds require lots of care from their parents.

Some babies hatch with feathers and can follow their mom around, swim and eat on their own.

Movement Flightless (ostrich, penguin…etc) Forelimbs modified for flight = wings Collarbones are fused making a strong base for flight muscles - fused bone is the furculum Air spaces make the bones light in weight Strong chest muscle attach to a keel of the sternum (breastbone)

What allows flight? Feathers Air cavities in bones decrease density Beaks rather then heavy jaws Extremely high metabolic rate Large hearts and high-pressure circulation Keen vision Excellent neuromuscular coordination

Environmental Interaction Occupy almost any habitat on earth 9,000 species Largest group of vertebrates except fishes Almost half the species migrate Predators, prey, scavengers,herbivores, omnivores

Migration Why migrate Northern hemisphere Southern hemisphere Increases food availability Breeding Avoid predators Reduce interspecies competition Northern hemisphere summers Southern hemisphere winters

Migration How do birds migrate? Some can travel as far as 11,200 miles Many follow landmarks such as rivers, coastlines. It is thought that they may also use the earths magnetic field The sun and the stars are also used as compass directors Some can travel as far as 11,200 miles Stimulus for migration Long days stimulate gonads to grow, fat deposits to increase and the urge to migrate north.