Ornithology Exam 2

birds have a “high energy” lifestyle, what does this mean

it means they are endothermic, where their body temp is regulated by internal metabolism

the higher body temp allows birds to be active in habitats, seasons and times of day not available to ectothermic reptile relatives

how do birds maintain a “high energy lifestyle”

• obtain and digest food

• excrete waste

• conserve water

• obtain and circulate oxygen

what kind of lung system do birds have

instead of expanding and filling with air, air is pumped through the Parabronchi(branching air tubes through lungs) of a birds lungs using “flow through” ventilation

what are the two types of air sacs of a birds lungs

anterior air sacs - near front of body

posterior air sacs - near back of body

inhalation 1

posterior air sacs expand, draw in aire

exhalation 1

posterior air sacs compress, push air into lungs

inhalation 2

anterior air sacs expand, draw air out of lungs

exhalation 2

anterior air sacs compress, push air out of bird

what is the relationship between air in parabronchi and blood in capillaries

they share cross current gas exchange

avian circulation is very similar to mammalian circulation because of convergence. what types of circulation systems do they have

double circulatory system(pulmonary and systematic) and a 4 chambered heart

the esophagus transports food, but can be modified. what are other uses for the esophagus

crop stores food for transport or later digestion

crop milk or “pigeon milk”

multi-chambered fermentation/digestion in leaf eating

what are the two chambers of a birds stomach and what do they do

the anterior - glandular proventriculus

the posterior - muscular gizzard

why do birds have short digestion times

because their intestinal tract is short, and they excrete nitrogenous waste in form of uric acid(produced in kidneys)

bird kidneys are incapable of concentrating salts, how do they get rid of the salt instead

they excrete excess salts using specialized salt glands

only two sexes in birds, what are they

male homogametic(ZZ)

female heterogametic(ZW)

how can you tell if a bird in male or female

if it’s male, during breeding season it will have a cloacal protuberance

if its female, it will have a single ovary on the left side(though you probably wont be able to tell)

what determines secondary sexual characteristics and behavior(bill color, plumage, song development, etc.)

the balance of testosterone and estrogen

what is bilateral gynandromorphy and how does it occur

a very rare error during development, where the bird is half female(ZW) and half male (ZZ)

what does the yolk contain

nutrients, energy

hormones(testosterone)

carotenoids(diet based color)

other immune factors

what about the egg can the female maniplulate

she can manipulate the quality of the egg depending on environment, egg number, sex ratio, and/or mate fitness

altricial

less developed, more dependent on parental care, less yolk

precocial

more developed, less dependent on parental care, more yolk

what happens during the egg fertilization process

the ovum is released from the follicle into the infundibulum

sperm travels up through oviduct to fertilize the ovum in the infundibulum

smooth muscle contractions move embryo through oviduct

albumin(egg whites) added to egg in magnum

chalazae provide support to stabilize yolk and embryo in egg

porous membranes added to developing egg in isthmus

shell added in uterus

what is the shell made out of and what does it do

made of calcium carbonate, phosphates, and magnesium, the egg shell provides structural support, and protection from soil invertebrates and microbes

it can also provide calcium for growing bones in developing embryo

what interferes with egg shall stability

DDT and other insecticides interfere with normal eggshell development, making them thinner and more fragile

how is laying eggs costly for the female

it takes energy, nutrients, calcium for bones, and hormonal effects on immune function

what are capital breeders

birds that draw energy reserves to produce a large “expensive” egg

what are income breeders

birds that increase feeding activity to ingest the daily energy needed for egg production

what is clutch size determined by

balance between reproductive output and survivorship

what is a song

its loud, often sung by a male in territorial display or to attract a female. often musical or pleasing to the earwha

why do females sing

to attract mates and defend territory and is likely ancestral

what is duetting important for

maintaining pair bond, synchronizing reproductive cycles, etc.

what are calls

short, simple vocalizations given by either sex

• distress, flight calls, feeding, nest calls, contact calls

where is the syrinx and what does it do

located at the junction of the trachea and bronchi, the syrinx vibrates to produce song