birds Flashcards
passerines
order - passeriformes
songbirds/perching birds
4 toed - one pointing backwards
most commonly kept - finches, canaries
psittacines
order - psittaciformes
parrots
most commonly kept:
small parrots - budgies, lovebirds, cockatiels
large parrots - african grey, amazon, cockatoo
raptors - birds of prey
order - accipitriformes - diurnal birds of prey eg hawks, buzzards
falconiformes - falcons
strigiformes = nocturnal birds of prey = owl
poultry and waterfowl
order - anseriformes:
ducks, geese, swans
order - galliformes
chickens, turkeys, pheasants, quail, peacock
anseriformes
family - anatidae
domestic duck and goose
genus - cygnus - swans
galliformes
class - aves
family - phasaianidae
chicken, turkey, pheasants, quail, peacock
ratites
ostriches and rheas
wild birds
many from passerine order =
blackbirds, starlings, blue tits
columbiformes = pigeons
charadriiformes = gulls
eye features
huge - >50% cranial volume in some birds
some have ability to recognise UV/polarised light
rarely blink - only closed when sleeping
have nictating membrane - 3rd eyelid functions like blinking
no meibomium gland
retina thick and avascular
cornea thinner and avascular
pecten
outfolding of the retinal surface
- rich blood supply
functions = may have role in retinal nourishment and reducing light reaching retina
ear features
no external pinna - outer ear protected by auricular feathers - act to funnel sound towards ear
integument
skin is thin and inelastic
reduced glands present - no sweat glands, no sebaceous glands
preen gland - uropygial gland - only one of consequence
uropygial gland
located at base of tail
variations in size, shape and number of openings
not present in ostrich, emu, some pigeons and some parrots
produces lipid rich secretion for feather water proofing and maintenance
other glands - auditory canal and cloacal glands
anatomy of a feather
vane - either side of central rachis = consists of series of barbs with interlocking barbules
rachis = contains capillaries during growth phase but loses them and becomes hollow as feather matures
calamus = anchors feather into follicle, hollow
feather shaft = combination of calamus and central rachis
feather types
contour feathers - outermost feathers, give colour and contour and protect from element
-coverts = small contour feathers of the wing
-remiges = large contour (flight feathers) of the wing
-retrices = tail feathers
semiplumes = under contour feathers, loose structure, provide insulation
down feathers = very loose structure with no barbs, provide insulation
powder down feathers = specialised down feather where tips of barbules disintegrate during preening - seen mostly in birds with reduced or absent preen gland
feathers
follicles confined to well defined areas called pterylae
between these the skin has to follicles - apteriae
feather growth
blood feathers = growing feathers
huge blood supply
nerve supply
moulting
occurs once a year
requires increased energy intake
affected by season, temperature, nutrition and individual factors
wing clipping
aiming to reduce ability for vertical lift - not stop them flying completely
skeletal system - flight
supports flight - by reducing weight
-fused bones
-lightweight structure
-small skull relative to body size
- no teeth
- by providing attachment points for flight muscles
- keel
coracoid
skeletal system - respiration and egg production
respiration - some bones hollow and house extensions of air sacs
strengthened by internal struts
egg production
- medullary bone provides source of stored calcium during times of peak egg production
skull
lightweight
no teeth
sclerotic rings supporting globe
spine
flexible and lightweight
cervical vertebrae - variable number = 11-25
thoracic vertebrae - notarium (fused to resist twisting forces of flight)
synsacrum - comprised of fused lumbar, sacral and some caudal vertebrae
final few caudal vertebrae make up pygostyle attachment of tail feathers and musculature
forelimbs and feet
forelimb - adapted to form wing
humerus - pneumatic bone
ulna and radius present
radial and ulnar bone supports secondary flight feathers
carpometacarpus - third major part of wing = supporting three digits
alula = first digit located on carpometacarpal joint and supporting small stiff feathers to aid in flight stability
hindlimb
similar to mammal
some bones fused forming -
tibiotarsus and tarsometatarsus
muscles
large pectoral muscles
- pectoralis major = largest muscle, wing depressor
supracoracoideus - wing elevator
pectoral girdle
designed to support the large flight muscles
scapula, clavicle (fused - furcula - wish bone)
coracoid, sternum
innominate bone - comprised of fused ileum, ischium and pubis
fused dorsally with synsacrum - makes single unit
bills and beaks
bony projections covered with a keratinised sheath - rhampotheca
continually growing - can lead to abnormalities
has blood and nerve supply
rhinotheca
upper beak
gnathotheca
lower beak
cere
waxy structure at base of beak
choanae
opening on roof of oral cavity
crop
muscular sac like structure in proximal oesophagus
not present in all birds - act as temporary food store prior to digestion
crop problems
sour crop - yeast infection/overgrowth
crop impaction = failure of food to leave crop
stomach
2 distant areas:
proventriculus
- glandular stomach
-secretion of digestive enzymes
- enxymatic digestion of food
ventriculus (gizzard)
- muscular stomach
- sometimes contains particles of ingested grit to aid grinding of food material
small intestine
highly coiled in herbivores/omnivores, shorter and simpler in meat eaters
duodenal loop - pancreas located between arms of this loop
jejunum - remnant of yolk sac
ileum
large intestine
relatively short
function = reabsorption of water and electrolytes
ceca
outpouchings of large intestine
cloaca regions
coprodeum - faeces and digestive waste
urodeum
proctodeum
cloaca
terminal portion of reproductive tract, urinary tract and gastrointestinal tract
