BIRDS
Arizona is blessed with over 500 species of
birds , with about 10% of these being
permanent residents
A BIRDS SKELETON
A. Bones are hollow with air sacs
B. Thin walled bones are strengthened by
struts
C. Forelimbs are modified into wings
A BIRDS SKELETON
D. Typically, the Achilles
tendon continues past the heel
to the 4 toes providing a
perching mechanism
E. Breast flight muscles attach
to a prominent keel on the
sternum
A BIRDS SKELETON
F. Horny beak adapted to diet, no teeth
G. 8-24 neck vertebrae in an extremely
flexible neck, may rotate through 280o
A BIRDS SKIN
A.Scales present
on legs and feet
o
B.Body covered with feathers
Vane 1. Contour feathers streamline +
protect body, + form flight surface of wing
Shaft 2. Down insulates the body
Quill Vane composed of barbs
A BIRDS SKIN
C. No skin glands. Preen
gland located at base of
tail produces oil to
lubricate feathers and
skin
D. Feathers are
periodically shed or
molted
A BIRDS CIRCULATORY SYSTEM
A. Four chambered heart, with two atrium (receiving)
+ two ventricles (pumping)
C. Nucleated red blood cells contain hemoglobin for
oxygen transport
D. High heart rate i.e. Hummingbirds= 1260/ minute
+ sparrows = 500/minute
A BIRDS DIGESTIVE SYSTEM
A.Food stored in crop before
being ground up by gizzard.
Intestine absorbs nutrients.
Feces exit via cloaca.
A.Food passes through system
quickly, 30 minutes in some
species. Yet high proportion
of nutrients are extracted
A BIRDS EXCRETORY SYSTEM
A.Kidneys excrete uric acid in a paste form to be mixed
with feces in cloaca.
B. No urinary bladder- this lightens the load.
C. C. Nasal salt gland ( in roadrunner & marine birds)
excretes excess salts from blood
THERMOREGULATION
A. Endothermic, heat source within cells, not
dependent on solar radiation for heat source
B. Homeothermic, body temperature rather
constant: can be maintained independent of
ambient temperature
C. Active temperature commonly 100-102
degrees F
REPRODUCTION
A. Establishment of territory and complex mating
rituals utilize vocalizations and displays.
Copulation is by opposition of cloacal
apertures.
B. Incubation of eggs is followed by extended
period of parental feeding + care.
C. Egg shells harden by calcium salts.
NERVOUS SYSTEM
A. Large part of the brain devoted to vision + coordination of muscles
B. Keen eyesight: can see color: can change focus from near to distant
objects very quickly. Predatory birds typically have binocular vision
C. Nocturnal birds with extremely acute hearing, usually cannot see
colors.
D. Except for vultures, most birds are not known to have a keen sense of
smell