Avian Dermatology

Question 1

functions of feathers

Answer 1

1. flight
2. insulation
3. water-proofing
4. display

Question 2

vane

Answer 2

the entire part of the feather that comes off of the rachis

includes:
- rachis
- barbs
- barbules
- hooks

Question 3

rachis

Answer 3

distal part of the main shaft with perpendicular filaments branching off

Question 4

barbs

Answer 4

branches off of the rachis

Question 5

barbules

Answer 5

branches off of the barbs

Question 6

hooks

Answer 6

tops on the end of the barbules that attach them with neighboring barbules to “zip up”

Question 7

calamus

Answer 7

the most proximal part of the main shaft with NO filaments branching off

Question 8

contour feather characteristics

Answer 8

calamus & rachis: stiff
vane: complete (zipped)
barbs: interlocking barbules and hooks
function: flight, water proof, insulation

Question 9

body contour feathers

Answer 9

line the entire body
attach into follicles

Question 10

flight contour feathers

Answer 10

line the wings and tails
attach into the periosteum of the bone

Question 11

remiges

Answer 11

feathers of the wings

primary: attach to hand bones
secondary: attach to the ulna

Question 12

rectrices

Answer 12

feathers of the tail

Question 13

semiplume feather characteristics

Answer 13

calamus & rachis: stiff
vane: incomplete
barbs: short +/- barbules with NO hooks
location: underneath and between body contour feathers
function: insulation

Question 14

down feather characteristics

Answer 14

calamus & rachis: short and soft
vane: none
barbs: long, NO barbs or hooks
location: underneath contour feathers
function: insulation

Question 15

bristle feather characteristics

Answer 15

calamus: short
rachis: long
barbs: short, only in proximal rachis; +/- barbules, NO hooks
location: face
function: sensation to touch/vibration

Question 16

filoplume feather characteristics

Answer 16

calamus: long
rachis: short
barbs: short, only in distal rachis; +/- barbules, NO hooks
location: between flight contour feathers
function: sensation to touch/vibration

Question 17

pterylae

Answer 17

feathered tracts
follicles where feathers will grow in

Question 18

pterylosis

Answer 18

pattern of feather distribution

varies by species/habitats

Question 19

apterylae

Answer 19

unfeathered tracts
areas without feather growth

Question 20

do water birds have apterylae

Answer 20

NO

Question 21

cervical apterylae

Answer 21

lack of feathers over the jugular vein

present in most non-water birds

Question 22

molting

Answer 22

process of feather replacement

1. old feather is pushed out by new feather
2. blood feather develops inside keratin sheath (contains blood supply and germinal tissue)
3. blood feather elongates to full length of adult feather
4. distal feather components mature as blood supply regresses and the keratin sheath gets preened away
5. blood supply continues to regress proximally and keratin sheath continues to fall away distally
6. mature feather, blood supply is gone and calamus is hollow

Question 23

what direction does maturation occur

Answer 23

distal to proximal

Question 24

blood feathers

Answer 24

developing feathers; indicates a bird is molting

bleeds and is painful if cut

Question 25

stress bars

Answer 25

damage to barbs/barbules during growth that does not lead to hemorrhage

Question 26

molt patterns

Answer 26

catastrophic
seasonal
gradual

Question 27

catastrophic

Answer 27

all feathers replaced during a short period

bird unable to fly during this time

ducks, geese

Question 28

seasonal

Answer 28

feathers replaced over a season (before breeding season)

passerines

Question 29

gradual

Answer 29

feathers replaced gradually over the molt period

raptors, large birds

Question 30

skin thickness in feathered vs unfeathered regions

Answer 30

feathered: thin skin
unfeathered: thick skin (ex. feet)

Question 31

do birds have glands in their skin

Answer 31

NO

only uropygial/preen glands

Question 32

what are the layers of bird skin

Answer 32

stratum corneum
stratum germinatuvum

(no lucid or granulosum)

Question 33

what skin layer contains follicles and fat in birds

Answer 33

dermis

Question 34

do birds have subcutis

Answer 34

minimal - may have air sacs