Birds 1 Flashcards
What are birds closely related to?
reptiles
What are the adaptations the bird has for flight?
- Warm-blooded
- Less dense
- Aerodynamic
What does warm blood provide for flight adaptation?
insulation and higher metabolic rate
What makes the bird aerodynamic?
wings and rigid structure
What is pneumatic bone?
Bone has pockets of air that are continuous with the respiratory system, allowing them to be less dense
What birds do not have pneumatic bone?
ostrich, diving birds, penguins
What bones are pneumatic?
proximal humerus, femur, vertebrae
What is the size of the bird’s eye in relation to brain?
Large
What are scleral ossicles?
Ring of bone inside the eye that supports the eye
How many occipital condyles does the bird have and what is the purpose?
1; helps with wider range of rotation of the neck
How does the jaw move and what is this called?
Cranial kinesis - upper jaw moves while the brain case remains stationary
What allows for cranial kinesis?
Craniofacial hinge at the base of the upper beak
What species have a synovial joint at the craniofacial hinge?
Psittacines (parrots)
How many cervical vertebrae are there?
Variable, can have 8-21
What is the purpose of having many cervical vertebrae?
Can bend neck a lot more, grooming, grasping of food
What is the notarium?
Fusion of last cervical and several thoracic vertebrae; is not always present
How many free thoracic vertebrae are there?
Usually 1 or more
What types of vertebrae make up the synsacrum?
(+/-) Caudal thoracic, lumbar, sacral, caudal
Where does the synsacrum sit?
DEEP to the pelvis, has a lot of stability
What is the pygostyle?
Fusion of distal caudal vertebrae
What are the 2 types of ribs of the bird?
Vertebral (project caudoventrally) and sternal (project caudodorsally)
What is the keel?
Ventral projection of the fused sternum; not present in all spp.
How can the keel be indicative of disease?
If you can readily feel the keel, there has been atrophy of the pectoral mm. and you can palpate the keep easily
What birds have flat sternums (i.e. no keel)?
ostriches
What makes up the triosseal canal?
scapula, coracoid, clavicle
What is another name for the clavicle?
Fused furcula or wishbone
Where does the glenoid cavity project?
laterally
What does the coracoid look like in relation to mammals and what is its function?
It is enlarged; limits compression of thorax during flight
Where do the pectoral mm. attach and what happens when they contract?
Attach to proximal aspect of humerus; contraction causes downstroke in flight
What muscle goes through the triosseal canal?
supracoracoid
Where does the supracoracoid m. attach and what happens when it contracts?
Attaches on dorsal aspect of proximal humerus; contraction causes upstroke in flight
What bone of the antebrachium is larger?
ulna
What is the fused bone of the antebrachium?
carpometacarpus
What is the alula?
First digit that is present (digit #2)
On which side is the pelvis incomplete?
ventrally
What is the shape of the pubis?
thin and long
Where is the renal fossa?
On ventral aspect of pelvis medial to the obturator foramen
What are the functions of the antitrochanter?
- Transfer rotational stability to femur
2. Limits abduction of pelvic limb
Why does the bird waddle?
Has limited abduction due to presence of antitrochanter
How does the femur articulate with the pelvis?
Via the femoral head and greater trochater
What is the tibiotarsus?
Tibia fused with first row of tarsal bones
What is the tarsometatarsus?
2nd row of tarsal bones fused with the metatarsals
Where are the flexor tendons located in the leg?
Caudal hock down to digits
How is a bird able to perch without expending a lot of energy?
When the hock flexes, the digits contract around the perch
What is the tendon locking mechanism?
Characteristic of some raptors; ratcheting system that interdigitates with the tendon sheath to lock tendons in place (useful for grabbing prey)
How many digits does the foot have?
variable #
How do you tell how many phalanges a digit has?
digit # + 1
Why can birds be mistaken for having osteomyelosclerosis?
Medullary bone (tibia, femur, pubic bone, ulna) can look like there is no medullary cavity on x-ray. This occurs bc the chicken frees up a lot of calcium if they are egg-laying for the shell, and they lay down a lot of bone in the medullary cavity. This is a normal condition.
What is medullary bone a store for?
Calcium
What are key features of avian skin?
- Thin and delicate
- Poorly vascularized
- No sweat glands
What is the patagium?
skin folds at the base of the wing
What is the propatagium?
Skin folds from carpus to shoulder
What is the postpatagium?
Skin folds from elbow to body wall
What is the purpose of the patagium?
Provides aerodynamics to wing for lift
What muscle is found in the propatagium?
Tensor propatagialis longa
What is a brood patch?
Area without feathers on the ventral abdomen that is thickened, has a large vascular supply, and provides heat. It is found in males and females, is a normal and seasonal occurrence.
What is the comb?
Comb-like structure on top of the head
What is the wattle?
Hanging structure from the ventral head/”chin”
What is the snood and why is it trimmed for commercial use?
Hanging flap of tissue that hangs over the beak of some species (i.e. turkeys). It is trimmed because other birds will peck at it if they get bored and this can kill the bird that has one.
Where are scales?
On the legs
Where is the spur?
On the distal leg, more prominent in males.
What happens to the spur in animals that are involved in cock-fighting?
The spur is removed and replaced with a blade
Where is the uropygial gland and what is it made up of?
At the base of the tail feathers, made up of keratinocytes
AKA “oil gland”
What are powder feathers and what is a spp. that they are found in?
Feathers that disintegrate into a powder that conditions other feathers; found in Kingfishers
What is the pterylae?
Area of skin with feathers
What is the apterylae and what can be found here?
Area of skin without feathers; one on neck where jugular vein can be found, have other areas on ventral abdomen
From what do feathers grow?
from a follicle
What does a feather have on the outside as it grows?
keratin sheath
What is at the very center of a growing feather?
pulp with an artery and vein
What is the pulp?
Innermost part of a growing feather that is a loose network of mesoderm
As a feather develops, what part of the quill does it come out of?
distal umbilicus
As a feather develops, what part of the quill do the artery and vein come out of/go into?
proximal umbilicus
What is the quill?
Hollow part of the feather
How do quill pens work?
The end is cut off to leave a sharp point, and when the quill is dipped in ink capillary action pulls the ink up into the quill
When is blood supply present in the feather?
Only during development
What happens to the feather as the bird matures?
It becomes hollow
When can a broken feather occur?
If bird is in too small of a cage, or if too large of a feather is pulled.
Can you pull small feathers and why?
Yes; if the feather is small enough the smooth msucle will contract to cut off the blood supply
What are stress bars?
Bars seen on feathers that are caused by increased levels of cortisol
What is another name for stress bars?
Segmental dysplasia
What are pin feathers?
Those have have not yet completely emerged from the keratin sheath
What is the rachis?
Continuation of the feather shaft
What is the vane and what is the leading vs. trailing edge?
Part of feather that comes off of the rachis;
Leading edge is smaller than the trailing edge, especially if the feather contacts a lot of wind
What is the shape of the outer/superficial edge of the feather?
convex
What is the shape of the inner/deep edge of the feather?
concave
What are the 2 components of the vane?
barbs and barbules
What is the difference between the proximally directed and distally directed barbules of the vane?
Distally directed have little hooks that hang on to the proximal barbules of the next barb
What is a feature of the feathers when there is a proper connection between them through the barbs and barbules?
It is water resistant
What is a feature of the cormorant feather and why?
Lacks hooked barbules in order to allow them to dive deeper for fish (makes them not as buoyant)
What are the types of feathers?
Contour, down (semiplume, filoplume), bristle
What are the types of contour feathers and what are they used for?
remiges (large feathers for flight)
retrices (tail feathers)
coverts (short and cover base of wings and tail)
What are the classifications of contour feathers and where are they located?
Primaries = attached to manus and embedded in the periosteum of the manus Secondaries = embedded in the periosteum of the ulna
What do you cut when clipping wings?
Cut first few primary feathers; don’t have to trim to the base of the follicle
What contour feather type pulls out of the follicles the easiest?
coverts
What are characteristics of down feathers?
They lack hooked barbules, do not have vanes, and the rachis is shorter than the barbs (are fuzzy)
What is the purpose of bristle feathers and where are they found?
Tactile function, found around mouth or eyelids and are common to insect catching birds
