1. Bird Review Test Tomorrow

2. Aves – adapted for flight (wings, feathers), endothermy, high metabolism, spine for flight, light bones Modern birds – horny bill, no teeth Close theropods – Velociraptor and T. Rex Feathers – temp. control, repel water, courtship, camouflage, balance Microraptor had asymmetrical feathers needed for flight

3. Archaeopteryx glided, but did not have powered flight. Eoalulavis had an alula, probably allowing for complex flight. Contour feathers are symmetrical, flight feathers are not. Young birds feature plumaceous (down) feathers Preening – remove parasites, smooth, clean, in place, oil resists water, anting prevents mites

4. Blue color in birds is caused by irregular reflections not pigments. Iridescence is caused by interference patterns in the feathers. Male birds are often more brightly colored than females. The postjuvenile molt makes a bird look like an adult. Loons dive, so they need to be more dense.

5. Birds use talons and the beak to move nest items. The sternum and the furcula (wishbone) allow for wing attachment. Domestic birds were bred for white meat which is no good for flight. Air travels further and faster over the top of the wing, creating lift. Lift must exceed weight. Thrust must exceed drag.

6. Birds curve the distal end of their wings up and draw their wings in to reduce drag on the upstroke. A bird’s tail balances, steers, brakes, & enhances lift. Beaks may be specialized for breaking seeds, tearing meat, straining water, reaching nectar, and more. The crop or esophagus may be used to store excess food.

7. Highly-oxygenated blood kept separate can deliver needed O 2 to the body during flight. The syrinx is the bird’s voice box. Birds stay warm by fluffing their feathers, shivering, tucking its beak, and countercurrent flow in its legs. Birds cool down by panting or spreading their wings.

8. pursuit fovea – depth perception, search fovea – wide angle of vision Bird sense of smell is weaker than that of humans. Sea birds must excrete more salt than the average bird. Sperm delivery is through direct cloaca to cloaca contact. Territory provides uninterrupted mating, a safe nest, and food.

9. Monogamy works in areas with plenty of evenly distributed resources. Polygyny works with less dependent young and patchy resources. Polyandry often results in predation of eggs and young. A nest provides a safe place to hatch and raise young. Egg turning prevents baby birds from sticking to the egg.

10. Altricial birds are born completely dependent on their parent(s). Precocial birds are more independent and rely less on their parents. Internal clocks or changes in day length (photoperiod) signal migration. Flying in a V conserves energy (except in the front). Birds navigate by the sun, the other stars, (maybe) earth’s magnetic field, and chemoreceptors.