1. List the "blue ribbons" which should
be awarded to birds for being first with certain characteristics or best
in certain ways.
2. State the advantages of homiothermy and
briefly describe the mechanisms for producing, conserving and regulating heat.
3. Describe the ways in which the breathing
system of birds is more efficient than that of mammals.
4. List some bird species which migrate seasonally;
summarize the factors which trigger migration and the ideas on how navigation
is accomplished.
5. Summarize the features of the anatomy and
physiology of birds which enable them to fly so efficiently.
6. Differentiate between ratites and carinates.
7. List and describe the points of evidence
which suggests an evolutionary relationship between birds and reptiles.
8. Notice the variety of birds in the different
orders, analyze the form and derivation of the order names, and tell about
the significance of the order Passeriformes.
9. Name and briefly describe the structure
and function of the different types of feathers.
10. Analyze the use of wings for flight and
for soaring.
11. Compare bird vision and human vision as
to efficiency, focusing arrangement, colors detected and structural differences.
12. Relate the various modifications of beak
and foot to the habitat and feeding habits (ecological niches) of different
kinds of birds.
13. Compare the senses of hearing, taste and
smell in birds and humans.
14. Define altricial and precocial; give an
example of a species of each type; relate these two characteristics to the
usual location of nests.
15. Briefly describe the nesting habits of
several representative bird species.
16. Outline courtship and mating practices
of birds. Include monogamous, polygynous and polyandrous relataionships.
Resources: Text: Animal Diversity, Chapter
19
Internet Resources
http://www.petersononline.com/birds/index.html
http://www.raptor.cvm.umn.edu/
http://www.ucmp.berkeley.edu/vertebrates/flight/enter.html
http://www.mhhe.com/hickmanad4e
PHYLUM CHORDATA: CLASS AVES
Birds ~9100 species; Arose from Archaeopteryx
, "anchient wing"
-Adaptations for flight: Fore appendages
modified as feathered wings;
endothermic; high metabolic rate;
neck flexible, posterior vertebrae fused;
bone lightened by numerous air
spaces (hollow); skull lightened by reduction
of bone, presence of horny beak
that lacks teeth.
Largest Orders Passeriformes
, perching songbirds ~60% of all birds
Anseriformes
, ducks, geese, swans
Falconiformes
, hawks, eagles, vultures
Galliformes
, pheasants, turkeys, domestic fowl
Broad Divisions (2 super-orders)
Neognathae- Ratites-
flat sternum, poorly developed pectoral muscles,
Flightless birds; ostrich,
kiwi, emu
Paleognathae- Carinates - flying birds, keeled sternum w/powerful flight muscles
**although some birds in
this group do not fly, it is a secondary development
due to selection pressures
(no predators, no need to fly)
Additional characteristics:
1. only one ovary in female (left)
2. amniotic egg w/hard calcareous shell
3. External incubation
young: altricial
- entirely dependent on parents, naked
(Altricial
---> to nourish)
precocial
- alert, active, covered w/down; can walk, run, swim,
one parent
usually remains (Precocial ---> early ripe)
Birdie Blue Ribbons:
1. Singing- syrinx, lower end of
trachae, used for singing
2. Homeothermy (Endothermic)
regulate body temperature internally within
narrow range, allows birds to be
more active year around.
Muscle contractions produce heat,
hypothalamus regulates heat gain and loss
Behavioral regulation- fluff reathers
to increase insulating props.
Tuck beak into feathers to reduce heat loss from respiratory tract.
3. Feathers
4. Humming birds: -Highest metabolic
rate, highest body temp
-fastest heart rate (300-1000 beats/min),
fastest breathing rate
-greatest rate of food intake
5. FOUR CHAMBERED HEART
6. Speed: swifts, on level, can travel more than 100 mph, some ducks 80mph
7. longest migration: Arctic tern
Arctic ---> Antarctic and back
~22,000 miles
8. Vision: large eyes, retina twice
as thick as humans
Hawks- have 8X as many rods and
cones as humans, therefore, 8X more acute
Nictitating membrane- third
eyelid, transparent, allows blink without hindering
vision
9. First to develop parental care of
young, nest building, courtship attachment of mates
-90% of all birds monogamous: single
male mates w/single female during breeding
season (swans, geese, eagles bond
for life)
-both parents participate in nest building, care of young
Some polygynous- males mate
w/ more than one female; occurs in species whose
young are less dependent at birth
(Prairie Chickens)
Few polyandrous- females mate w/ more than one male.
Pair formation:
1. sexes meet only for copulation
(sage grouse)
2. Sexes remain together for a few
days at time of copulation (humming bird)
3. Pair formed some time before
copulation but ends shortly after (many ducks)
4. Pair for breeding season (majority
of passeriformes)
5. Pair for life
FEATHERS
Plumage- covering of feathers
2 functions: 1. form flight surfaces,
provide lift and aid steering
2. prevent
excessive heat loss, permits endothermic maintenance of
high
metabolic rate
**additional roles in courtship, incubation, and water proofing
-epidermal structures, development closely resembles growth of reptilian scale
-mature feather becomes cut off
from blood and essentially dies, becoming
keratinized epidermal structure
-Renewal of feathers regular
due to wear and tear
Molting: timing varies
Post natal- down covered
chick grows juvenile feathers
Post juvenile- usually
in fall, results in plumage resembling adult
Pre-nuptial- late
winter/early spring, prior to breeding season, exposes
plumage; important
to courtship
Post nuptial- usually
between July and October
**flight feathers frequently
lost in a particular sequence (and in symmetrical pairs)
so birds are not completely
deprived of flight
Contour Feathers- obvious, cover body; wings and tail
-feathers consist of rachis w/right and left vanes (inner and outer webs)
-barbs branch off rachis (shaft),
barbules branch off barbs
-barbules of adjacent barbs overlap
one another and ends of barbules locked
together w/ hooklike hamuli
-Preening- maintaining clean plumage
Down- insulating feather, small,
soft, multibranched
-most color from feather
pigments produced during feather formation; other
colors termed structural
colors, arise from irregularities on surface of feather
that diffract white
light
FLIGHT
*wing adapted for different kinds of flight
but mechanics the same for all
-wing forms air foil
Anterior thicker than posterior margin
Upper surface slightly convex, lower
concave
Air passing over travels faster and
further than air passing under; decreases air
pressure on upper surface creating
lift
*lift increased by increasing angle
of leading edge (angle of attack), however,
as angle increases so does turbulance
Turbulance decreased by slotting at wing tips on alula
Alula- group of small feathers supported by bones of second digit
Tail- balancing, steering, breaking functions
Four Kinds of Flight used by different birds or by same bird at different times
Gliding flight- wing stationary,
bird loses altitude, will turn into wind to increase
lift or use for landing (water fowl)
Flapping flight- generates power,
most common type, variations in shape and
flapping patterns result in species-specific
speed and maneuverability
Soaring flight- allows some birds
to remain airborne w/little energy expense,
wing stationary, utilize up drafts.
Wings wide and slotted; Hawks, eagles, owls
Hovering flight- gulls take advantage
of winds deflected upward
Humming birds- hover in still air, fan
wings back and forth 50-80 beats per second
MIGRATION- periodic round trips between breeding and nonbreeding areas, most annual
-approx 1/2 of birds migrate, since 70%
of land in No. Hemi., most fly north for summer,
south for winter
-allows birds to avoid climatic extremes
and to secure adequate food, shelter and space
throughout year.
-occasionally an east/west movement or altitude change
Stimuli- species-specific physiological
conditions, genetic clocks and environmental
factors influence preparation
Photoperiod- changes initiate
seasonal changes in gonadal devel.
spring increase ---> triggers
development
fall decrease ---> triggers regression
fat deposition can also accompany changes in photoperiod
-some birds in captivity show "migratory restlessness", impulses for migration
Pineal body located on roof of forebrain, role in gonadal development
Anterior lobe of pituitary implicated in mediating photoperiod response
Manipulation experiments
Navigation
Route based- keep track of land marks
(visual or auditory) on outward journey, reverse
map used on return
Location based- establishing direction
of destination using info available at journey
site of origin, use sun compass, celestial
cues or earths magnetic fields