ANATOMY - Avian Flashcards
What are the two principles of flight?
Weight reduction
Power generation
What are the seven functions of feathers?
Streamlining
Reduce friction
Increase surface area
Protection
Contribute to thermoregulation
Camouflage
Communication
What are the two main types of feathers found on avian species?
Contour feathers
Covert feathers
What are the two types of contour feathers?
Flight feathers (remiges)
Tail feathers (retrices)
What is the function of flight feathers?
Flight feathers provide lift and stability during flight
What is the function of tail feathers?
Tail feathers allow for steering and manoeuvring during flight
Label the following structures on this contour feather
What is the function of the hooklets found in feathers?
Hooklets interlock the barbules to create a sturdy and cohesive structure to maintain the overall shape and integrity of the feather
Describe briefly how feathers develop in avian species
Feathers develop from vascular dermal papillae located within feather follicles. Epidermal cells will proliferate within a vascularised, protective corneal sheath to form the blood/pin feathers. As the feather continues to develop, the vascular supply will regress and the corneal sheath will break away, revealing the mature feather underneath
What is a key indicator that a bird has undergone stress during feather development?
Fault bar formation within their feathers
How should you carry out wing trimming?
Trim the first four primary flight feathers annually
What is the propatagium?
The propatagium is the elastic fold of skin extending from the shoulder to the carpal joint, making up the leading edge of the wing
(T/F) Avian species have no sweat or sebaceous glands
TRUE.
What is the average body temperature for birds?
40 - 41°C
What are the five mechanisms used by avian species to cool down?
Expose underwing
Panting
Ruffle feathers
Wetting abdomen
Expose legs
Why do avian species expose their legs to cool down?
Avian species have a counter-current mechanisms, i.e. a network of blood vessels in their legs where warm arterial blood flows alongside cool venous blood, allowing for heat exchange to occur with the warm arterial blood cooling down as it passes the cool venous blood
Where is the uropygial (preen) gland located?
The uropygial (preen) gland is located on the dorsum of the tail
What are the functions of the secretions produced by the uropygial (preen) gland?
The secretions from the uropygial (preen) gland are used during preening to maintain the condition of the feathers along with waterproofing and ectoparasite control
What are the five structural adaptations of the axial skeleton in avian species which contribute to their flying ability?
Pneumatised bones
Beak/bill
Fused vertebrae
Sternum will deep keel
Pectoral girdle
What are pneumatised bones?
Skeletal pneumaticity is the presence of air spaces within bones
Why do birds have a beak?
Birds have a beak because is it more lightweight than teeth and muscles of mastication, allowing them to be more lightweight for flying
Which structural adaptation of the skull allows birds to have increased mobility of their head?
Birds only have one occipital condyle which increases the mobility of their head
What is the function of the cranio-facial hinge?
The cranio-facial hinge is a joint between the upper beak and the skull which allows for increased mobility of the beak during feeding
What is the function of the quadrate bones?
The quadrate bones act as a hinge between the lower beak and the skull to increase the movement and flexibility of the beak during feeding
Which region of the eye is prone to haemorrhage in avian species?
The highly vascularised pecten attached to the retina is prone to haemorrhage
What is the function of the salt nasal gland found in shorebirds?
The salt nasal gland is involved in osmoregulation
How many cervical vertebrae do avian species have?
8 - 25 cervical vertebrae
What are the three regions of the fused vertebrae found in avian species?
Notarium (T3 - T5)
Synsacrum
Pygostyle
What is the function of the deep keel present on the sternum of avian species?
The deep keep of the sternum increases the surface area for the attachment of flight muscles
Which bones does the deep keel of the sternum articulate with?
Coracoid bones
What are the four structures that make up the pectoral girdle in avian species?
Coracoid bones
Scapulae
Clavicles
Furcula
What is the function of the pectoral girdle in avian species?
The pectoral girdle forms a stable base for the wings to generate lift and propulsion
What are the six bones of the avian forelimb (wing)?
Humerus
Ulna
Radius
Alula
Metacarpal
Manus
What is the function of the alula?
The alula prevents stalling when a birds is coming in to land
Which vein of the avian forelimb (wing) is used for venepuncture?
Brachial vein (wing vein)
What are the four bones of the avian hindlimb?
Femur
Tibiotarsus
Tarsometatarsus
Digits