Intro avian

True

Bird skin is thinner and more delicate than that of mammals.

True

In most cases the subcutaneous layer is insufficient to suture surgically

Podotheca

non-feathered part of the leg

Uropygial glands and holocrine glands

glands of the external ear canal- only epithelial glands

generally 40- 44°C

Normal body temperature for birds

Hyperthermic birds

dissipate heat by increasing respiration and holding the wings away from the body.

Cold birds

ruffle their feathers and crouch to retain heat.

scales (bird's feet and legs)

raised areas of highly keratinized epidermis separated by a fold of less keratinized skin

Claws

have a strongly keratinized dorsal plate and a softer ventral plate that grows more slowly

Vitamin A deficiency

causes hyperkeratosis and overgrown claws

Scaly mite (Cnemidocoptes sp.)

induce hyperkeratosis and disrupt normal scale formation

Rhamphotheca

horny keratin covering of the bones of the upper and lower jaw

Gnathotheca

mandibular rhamphotheca

gonys

ventral midline in Gnathotheca

Rhinotheca

maxillary rhamphotheca

Tomia

cutting edge of both the upper and lower beak

Inter-ramular region

soft tissue between the mandibular rami

feathers

Unique to birds; evolved from reptilian scales

Pterylae

feather tracts

Apterylae/ Apteria

- unfeathered areas

Calamus or Quill

central stalk or shaft of the feather; below skin level

Rachis

feather above skin level

True

feather pulp and artery regress as the feather matures

Blood Feather

If an emerging feather is cut or damaged

Barbs

emerging laterally to the rachis

Barbules

emerging from the barbs

Barbicels

hooks that interlocks barbs and barbules; enables waterproofing

Vane

portion of the feather extending either side of the rachis

Plumaceous

vane that are soft and fluffy

Pennaceous

vane that are closely interlocked

Contour feathers

- those that cover the bird's body

Covert feathers

small contour feathers present on the wings and tail

Flight feathers (Remiges)

pennaceous vane; asymmetric in form to enable flight

Tail feathers (Retrices)

- structurally similar to remiges; symmetrical

Plume (Down) feathers

- undercoat feather

Powder Downs

specialized down feathers located anterior to the hips; performs a dry lubrication function

Powder Downs

often the first feathers to show abnormalities if a bird is infected with circovirus

Semiplume feathers

have fluffy vanes, but the rachis is longer than the longest barb.

Filoplumes

- hair-like; long rachis and short barbs at the end

Bristles

- have a stiff rachis with few or no barbs at the end, and function like whiskers; tactile function

Hypopenna

-after feather

Colour of feathers

- combination of pigments and feather structure.

Carotenoids or psittacins

(yellow pigments absorbed from the diet, including reds, oranges and pinks) - foreground colour.

Melanins

(including black, grey and brown) -background and the foreground colour.

Moulting

- controlled by a wide range of factors including thyroid activity, reproductive hormones, photoperiod, body condition, age and diet.

true

most birds go on to moult one to two times annually

1. Inner primaries
2. Outer primaries
3. Secondaries and tail feathers
4. Body Contour feathers

The pattern of moulting (in order)

true

The requirement for flight means that birds have evolved with bones that are lightweight, but aerodynamically strong

true

The periosteal blood supply is the predominant source of blood to the bone

true

The skeleton of avians are composed of thin brittle cortices and wide medullas

Pneumatic bones

are found in the skull, vertebrae, pelvis, sternum, ribs, humerus and sometimes the femur; help with flying

Medullary bones

have interconnecting spicules growing from the endosteal surface of the cortical bone and fill the medullary cavity in response to estrogens; source of calcium for the eggshell for laying hen and only occurs in birds and some reptiles

Premaxilla, Nasal bone, Maxilla

what are the 3 Bones of the upper jaw

11-12 Cervical Spine

provide sufficient flexibility for a parrot to reach its tail and uropygial gland

Notarium

Thoracic vertebrae are somewhat flexible in psittacines, but are fused in many other species to form the \______________

Synsacrum

10-23 fused thoracic, lumbar, sacral and caudal vertebrae; followed by 5-8 free caudal vertebrae and then the pygostyle (four to ten fused caudal vertebrae), which supports the tail retrices.

C: 14 Th: 7 L+S: 14 C: 7

Vertebral formula of chicken

Notarium

- Formed from the 2-5 thoracic vertebrae and helps provide rigidity in the back when a bird is flapping its wings.

Synsacrum

absorbs compression shock whenever the bird lands at high speed, provides support for the independent movement of wings and legs

pygostyle

are the fused and flattened caudal vertebrae that support the tail feathers

bone

Dorsal vertebral component of the ribs (made of \______)

ossified cartilage

Ventral sternal component of the ribs (made of \____________ \_____________)

true

There are 3-9 pairs of ribs

Uncinate process

\_________ \___________ /caudodorsal process on vertebral ribs

true

On vertebral ribs, all except the first and last have uncinate (meaning hooked or bent)processes

Carina

prominent ventral medial keel in many species

true

'Flat' in flightless birds (like ostriches & rheas) but a large keel or carina (site of attachment of the large flight muscles) is present in most birds

the pectoralis and subcontractors muscles

Major muscles of flight

thoracic girdle

Made up of the scapulae, the coracoids and the clavicles

Scapula

strongly attached to the ribs

Coracoid

- massive in most birds, functioning to hold the wing away from the sternum during flight

Clavicles

fuse ventrally to form the furcula

Humerus

- in most species, is a pneumatic bone

true

The ulna is larger than the radius in birds

digitus alularis (II)

the alular digit with one phalanx

digitus minor (IV)

the minor digit, also with one phalanx

digitus major (III)

the major digit with two phalanges

pelvic girdle

contains the ilium, ischium and pubis, all partially fused with each other and the synsacrum

pelvic girdle

Incomplete ventrally for passage of large fragile eggs

true

the pelvic symphysis is present only in ostriches and rheas

true

Patella is present in most birds

Tibiotarsus

\_____________ is formed by the fusion of the tibia and the proximal row of tarsal bones

true

The fibula extends two-thirds of the way down the tibiotarsus, to which it is fused.

true

There are four digits in parrots: I has two phalanges and is usually directed backwards; II has three phalanges; III has four phalanges; and IV has five phalanges

true

The most common foot design: perching feet, three digits are forward-facing, while the first digit (hallux) faces backward.

true

The second most common foot formation among birds: four digits, but two digits facing forward and two digits facing backward. This foot is traditionally found on tree clinging birds like woodpeckers, in parrot species and owls.

true

Birds have no soft palate

Choana (slit)

opening to the nasal passageway

Salivary glands

- produce mucus; abundant on the walls of oropharynx; best developed in birds that evolved on a dry diet

oesophagus

\______________ goes down the right side of the neck - opposite to its situation in mammals

crop

is a dilatation of the oesophagus in which food is stored and softened prior to passage into the proventriculus. Very prominent in psittacines, but very small in most passerines

true

No digestion takes place in the crop

Cranial proventriculus (or glandular stomach)

thin walled and is lined with mucus-secreting columnar epithelial cells and oxynticipeptic cells (HCl and pepsinogen)

caudal ventriculus or gizzard

part of the digestive system of birds that varies in size and shape between species

Koilin

In granivorous birds, glands in the thick, biconvex, muscular gizzard wall secrete a hard, proteinaceous, cuticular lining called ________________

true

Duodenum, jejunum and ileum are located on the right side of the abdomen

Large paired ceca

absent or vestigial in psittacines, passerines and Columbiformes

Caeca

are the site of blackhead (histomoniasis) infection in gallinaceous birds.

Gall bladder

is usually absent in psittacines and ostriches, but is present in many other species

vitelline diverticulum (Merkel's diverticulum)

is the remnant of the yolk duct.