Birds

1. Birds

2. Diversity • Diversity • Birds are found in every niche/habitat on Earth. • This makesthem the most diverse class of terrestrial vertebrates. • Birds feed on nectar, plants, seeds, insects, rodents, fish, rotting animal flesh/decaying matter, or other birds.

3. Diversity • Diversity • Range in size from the tiny hummingbirds to the huge Ostrich and Emu. • There are about 8,800–10,200 living bird species • About 120–130 more species have become extinct in the span of human history in the world,

4. Diversity • Diversity • Most birds are diurnal (active during the day). • Some birds are nocturnal (night hours) or crepuscular (twilight hours). • Many birds migrate long distances to utilize optimum habitats (e.g., Arctic Tern) • While others spend almost all their time at sea (e.g. the Wandering Albatross). • Some, such as frigate birds, stay aloft for days at a time, even sleeping on the wing.

5. General Characteristics • Respiratory system • Birds have a high oxygen demand (because of high metabolic rate) • They meet this by having as respiratory system more efficient than that of a mammal or a reptile. • Birds ventilate their lungs by means of posterior and anterior air sacs (typically nine)

6. General Characteristics • Respiratory system • Three sets of organs involved in respiration: • the anterior air sacs • the lungs • the posterior air sacs • The posterior and anterior air sacs expand during inhalation. • Air enters the bird via the trachea. • A diaphragm is absent in birds

7. General Characteristics • Circulatory system • Four chambered hearts, just like humans • Allows for efficient nutrient dispersion throughout the body which provides birds with the energy they need to fly and lead highly active lives. • FYI: A hummingbird's heart beats at a rate of 1000 beats per minute, that is about 16.5 beats per second

8. General Characteristics • Digestive system • Very high metabolic rate • Why? To keep up with their constant need for energy (constantly mobile) • Bony beak with no teeth • Possess gizzard (for grinding food) • Complete digestive tract • Includes stomach, gizzard, intestine, anus, mouth

9. General Characteristics • Flight • Characterized primarily by feathers, forelimbs are modified as wings • Some birds are flightless • Include: penguins, ostrich, kiwi, and the extinct Dodo • Flightless species are vulnerable to extinction • Adaptations for Flight • Hollow bones • Large wing span • Great sight and/or hearing

10. General Characteristics • Process whereby a chick acquires feathers until it can fly is called "fledging". • Types of feather • Contour feathers are the predominant feathers covering the bird's body. • Can be divided into flight feathers and body feathers • Covert feathers are small contour feathers • Cover the bases of the wing and tail feathers. • Semiplume feathers are important in thermal insulation.

11. General Characteristics • Types of feather • Filoplumeshave a long fine shaft and short barbs or barbules. • Provide sensory information about the position of adjacent contour feathers. • Down feathers are fluffy feathers that may be found over the entire body • Used for insulation • Powder-down feathers shed a white waxy powder composed of keratin. • Form a waterproof barrier for contour feathers.

13. General Characteristics • Reproduction • Oviparous (lay hard-shelled eggs) • Some birds, such as pigeons, geese, and Red-Crowned cranes, remain with their mates for life (or for a long period) and may produce offspring on a regular basis.

14. General Characteristics • Social systems and parental care • Birds are polyandry, polygyny, or monogamy • Monogamy is seen in approximately 91% of all bird species. • Monogamous species of males and females pair for the breeding season. • In some cases, the individuals may pair for life. • Ex: geese, most pigeon species • Male birds are just as adept at parental care as females.

15. General Characteristics • Birds and Humans • Important food source for humans • Birds grown for human consumption are referred to as poultry. • Birds long been used by humans to perform tasks. • Homing pigeons were used to carry messages • Falcons are still used for hunting • Canaries were used in coal mines to indicate the presence of poisonous gases

16. General Characteristics • Birds and Humans, cont. • Pets • Parrots, parrotlets, canaries • Bird can carry diseases that can be contracted by humans • Include salmonella, Newcastle's disease, avian tuberculosis, and the avian influenza

17. Classification • Classification • Birds form a class, whose scientific name is Aves. • The earliest known species of class Aves is Archaeopteryx lithographica, from the Late Jurassic period.

18. Classification • Classification, cont. • Modern birds are divided into two superorders: • Paleognathae—mostly flightless birds • Ex: ostriches, emus, kiwi

19. Classification • Classification, cont. • Modern birds are divided into two superorders: 2. Neognathae—containing all other birds • Ex: ducks, albatross, loon, penguins, pelican, stork, falcon, quail, crane, dove, pigeon, parrot, owl, hummingbird, woodpecker)