2. Avian Anatomy and Physiology Pt 1 Flashcards
What is included in the integument system of birds?
skin, glands, beaks, claws and feathers
What makes the epidermis layer of birds different from our common species?
thin, flat epithelia cells that prod keratin - req for feathers and outer sheath of beak and claws
What makes the dermis of bird different than our common species
thicker, tough fibrous connective tissue
storage for fat
smooth muscles move feather follicles - for heat regulation
Do birds have sweat glands? What type of glands do birds have?
No sweat glands in birds!
Instead have a Uropygial gland or preen gland
located on the dorsal surface at upper base of tail, it secretes oily fatty substance that waterproofs their feathers
it’ll vary in size with species with some completely lacking it in the case of some parrots and flightless birds (these types often prefer dust to water baths
What is a beak made out of?
Derivatives of a bird’s skin
upper and lower mandible covered with a horny keratin layer - grows continuously
vary in hardness and flexibility, depending on function
What are claws made of?
Ends of each toe possess horny sheath derived from specialized scales that grow continuously
species differ in type of claws bc of perching habits and methods of procuring food
What are the 5 functions of feathers?
- Flight
- protection
- Thermoregulation
- Canouflage
- Communication behaviours
Outgrowths of skin, non-living
made of protein, sensations only at the base
What are contour feathers?
Most visible feathers
give shape to a bird
most compact microstructure is calamus, rachis/shaft, vane (barbs, barbules, hooklets)
What is a semiplume?
Commonly found under contour feathers especially along sides, neck and back
provide insulation and also flexibility and buoyancy in water birds
central rachis with free barbs (lack barbules and hooklets)
What are down feathers?
Soft and fluffy, located next to the skin also function in insulation
no true rachis/shaft, simply a calamus with free barbs
Might also be pulled out to use as nesting materials
What is a powder down feather?
A specialized type of down feather
unusual as they never stop growing, they also disintegrate at the tip of creating a waxy powder
this powder is spread thruout the plumage thru preening
helps clean and waterproof other feathers
highly developed in birds that don’t have a uropygial gland
What is a filoplume feather?
A sensory or decorative feather in function
elongated rachis with barbs only at distal portion
What are bristle feathers?
Modified contour feathers
thought to serve as a sense of touch
loc depends upon species
long, tapered rachis; few (or no) barbs (may or may not have barbules)
Where are feathers typically located?
Feathers do not originate from the entire body
feather overlap each other and laid down in tracts with areas of bare skin in between
these bare areas are called apteria
What happens when a bird molts?
Process of feather replacement
occurs in a species-specific pattern - allows bird to continue normal activities
Usually replacement is symmetrical - one or two pairs of flight feathers molted at a tie, major annual molt timed; often in the fall, waterfowl loose all their feathers at once following the breeding season
Where do feathers develop from?
Develop from papillae in feather tracts of dermis
What is a growing feather also called? What happens as a feather grows?
newly developed feather pushes old feather out
feather emerges, covered by periderm
periderm is removed by preening
blood vessels from dermis reach into new feather
when feather is fully grown, blood dries up, and rachis is pinched closed
What is the objective of feather clipping? What do we need to watch out for?
Objective is to clip wing feathers so that birds cannot fly (no lift) but can still glide (to land safely from a perch)|trim 5-7 flight feathers under the coverts to leave a smooth appearance
can trim the outermost feathers or leave two or more outermost primary feathers intact
NEVER TRIM BLOOD FEATHERS, or the feather on either side
What is a ‘fault bar’?
A stress bar
or a weakened area on feather vane where barbs lack barbules
feather is stressed during its growth when blood flow is interrupted
most common stressor is poor diet
What might cause feather damage?
external parasites chew and consume parts of the feather vanes, creating weak points
damages also from daily wear and tear
Why might a bird pick and pluck its feathers?
Disorder among captive psittacines (parrots, cockatiels, budgies) and sometimes imprinted raptors (hawks, falcons)
Caused by boredom or dz;
parasites, bacterial or fungal infection, toxins, if small birds (budgies, cockatiels) are feather picking, it is more likely a medical cause
if lger birds are feather picking it is almost always behavioural
Tx: cure/rule out medical cause and enrich environment
What modifications in the skeletal system has allowed for flight and walking?
reduction in # of bones
Fusion of some bones to form plates
reduction in bone density
loss of internal bone matrix - some bones hollow and filled with air spaces
