Avian Dermatology Flashcards
functions of feathers
- flight
- insulation
- water-proofing
- display
vane
the entire part of the feather that comes off of the rachis
includes:
- rachis
- barbs
- barbules
- hooks
rachis
distal part of the main shaft with perpendicular filaments branching off
barbs
branches off of the rachis
barbules
branches off of the barbs
hooks
tops on the end of the barbules that attach them with neighboring barbules to “zip up”
calamus
the most proximal part of the main shaft with NO filaments branching off
contour feather characteristics
calamus & rachis: stiff
vane: complete (zipped)
barbs: interlocking barbules and hooks
function: flight, water proof, insulation
body contour feathers
line the entire body
attach into follicles
flight contour feathers
line the wings and tails
attach into the periosteum of the bone
remiges
feathers of the wings
primary: attach to hand bones
secondary: attach to the ulna
rectrices
feathers of the tail
semiplume feather characteristics
calamus & rachis: stiff
vane: incomplete
barbs: short +/- barbules with NO hooks
location: underneath and between body contour feathers
function: insulation
down feather characteristics
calamus & rachis: short and soft
vane: none
barbs: long, NO barbs or hooks
location: underneath contour feathers
function: insulation
bristle feather characteristics
calamus: short
rachis: long
barbs: short, only in proximal rachis; +/- barbules, NO hooks
location: face
function: sensation to touch/vibration
filoplume feather characteristics
calamus: long
rachis: short
barbs: short, only in distal rachis; +/- barbules, NO hooks
location: between flight contour feathers
function: sensation to touch/vibration
pterylae
feathered tracts
follicles where feathers will grow in
pterylosis
pattern of feather distribution
varies by species/habitats
apterylae
unfeathered tracts
areas without feather growth
do water birds have apterylae
NO
cervical apterylae
lack of feathers over the jugular vein
present in most non-water birds
molting
process of feather replacement
- old feather is pushed out by new feather
- blood feather develops inside keratin sheath (contains blood supply and germinal tissue)
- blood feather elongates to full length of adult feather
- distal feather components mature as blood supply regresses and the keratin sheath gets preened away
- blood supply continues to regress proximally and keratin sheath continues to fall away distally
- mature feather, blood supply is gone and calamus is hollow
what direction does maturation occur
distal to proximal
blood feathers
developing feathers; indicates a bird is molting
bleeds and is painful if cut
stress bars
damage to barbs/barbules during growth that does not lead to hemorrhage
molt patterns
catastrophic
seasonal
gradual
catastrophic
all feathers replaced during a short period
bird unable to fly during this time
ducks, geese
seasonal
feathers replaced over a season (before breeding season)
passerines
gradual
feathers replaced gradually over the molt period
raptors, large birds
skin thickness in feathered vs unfeathered regions
feathered: thin skin
unfeathered: thick skin (ex. feet)
do birds have glands in their skin
NO
only uropygial/preen glands
what are the layers of bird skin
stratum corneum
stratum germinatuvum
(no lucid or granulosum)
what skin layer contains follicles and fat in birds
dermis
do birds have subcutis
minimal - may have air sacs
