BIOL 1442 Ch 29 Birds

Birds are

endothermic

Birds have two main types of feathers:

contour feathers and down feathers

The feathers on a wing are

flexible

The two types of flight feathers include

primary feathers and secondary feathers

Flapping of the entire wing occurs through

actions of the chest muscles (contraction of pectoralis muscles)

The flight muscles attach to a

blade-shaped keel projecting ventrally from the sternum

The flight muscles are rich with

oxygen-storing myoglobin

The frucula (fused clavicle) is

flexible enough to bend and provide support to the shoulder girdle during flapping

An important requirement for flight is

low body weight

Pneumatic bones

bones that are hollow rather than filled with tissue

The jaw in birds is lightened because

the teeth and beak are made of keratin

birds lack a ( ) bladder

urinary

In birds, uric acid is eliminated as

urate salts

Females of most bird species only posses one

functional (left) ovary

The air spaces of pneumatic bones can be connected to

air sacs

Airflow through bird lungs is

unidirectional

Ventilation is provided by

parabronchi (minimally expandable lungs)

Syrinx

voice box that resides near the junction of the trachea and bronchi

Birds typically have a ( ) neck and ( ) tail

elongate s-shaped; short (pygostyle)

The epidermis in birds is

very thin without sweat glands

The uropygial gland is essential to

preening

The nervous system in birds consists of

12 pairs of cranial nerves, very large cerebellum and optic lobes, single bone in the middle ear

Birds have a ( ) circulatory system with

closed; two atria and two ventricles

Birds belong to a group of diaspids known as

the archosaurs

Saurischia diverged into two groups:

Apatosaurs and theropods

Apatosaurs include

long-necked herbivorous dinosaurs

Theropods include

bipedal predators that gave rise to birds

The clade Neornithes includes the

avian crown group

Archaeopteryx

has the characteristics of both maniraptoran dinosaurs and modern birds

arboreal hypothesis

tree-dwelling precursors to modern birds jumped from branch to branch using their feathers for gliding before becoming fully capable of flapping flight

Terrestrial hypothesis

running was the stimulus for flight

Feathers provide ( ) which is beneficial for

insulation; thermoregulatory purposes when heat is being produced internally

Enantiornithes

dominant bird type in the cretaceous period

Orinthurae

became the dominant birds after the extinction of Enantiornithes

The three major clades of birds include:

Paleognathae, galloanserae, and neoaves

Paleognathae include

ostriches, emus, rheas, and kiwis

Galloanserae include

pheasants, ducks, geese, and swans

Neoaves include 5 clades:

Strisores, columbaves, gruiformes, aequorlitornithes, and inopinaves

Stirsores include

nightjars, swifts, and hummingbirds

Columbaves include

turacos, bustards, cuckoos, pigeons, and doves

Gruiforms include

cranes

Aequorlitornithes include

diving birds, wading birds, and shorebirds

Inopinaves include

hawks, owls, woodpeckers, parrots, falcons, crows, and songbirds