birds Flashcards
How many species of birds are there?
9700
How many orders of birds are there?
27
What is the size range of birds?
2g - 120kg. 15kg being the largest flier
Name some members of the galliform family
Chicken, pheasant, peafowl, turkey and quail
What is a normal body temperature for a bird?
40-42°C
Birds have a high metabolic rate, this…
Increases flying efficiency and food conversion. They are fast healers
Name energy expensive times for a bird
Flight, courtship and breeding, moulting and growth (for altricial birds)
How do birds conserve heat?
Down feathers, shivering pectorals, put head under wing, sitting down and roosting/huddling
How do birds loose heat?
Extend wings, airsacs, shade seeking/bathing, thermal panting (ostrich) and gular fluttering
How are a bird’s different senses?
Excellent vision, good hearing, poor smell/taste, good touch
Define poultry
Any member of the galliform family or domestic waterfowl, e.g. chicken, duck, goose, turkey, guineafowl, etc.
What are chickens beaks made of?
Keratin
What is the function of scleral ossicles?
The keep the eye under pressure during flight
What kind of vision do birds have?
Colour vision, binocular vision and infrared vision
What is a nictitating membrane?
A membrane that forms an inner eyelid in birds, reptiles and some mammals, it protects the eye from dust and keeps it moist
What is unusual about the iris in birds?
The iris muscle is striated and under voluntary control
What are cryptochromes?
Molecules in the retina which undergo a chemical reaction that is sensitive to magnetic forces, birds use these to navigate during migration
What are the different types of feet in birds?
Digitigrade - walk on their toes
Anisodactyl - claw-like
Zygodactyl - two yes forward and two back
Palmate - usually webbed
What do birds use feathers for?
Flight, temperature regulation, behaviour (e.g. courtship)
How do birds maintain their feathers?
Relocking barbs, using preen gland with vitamin d. Dust bathing. Pigeons and parrots have powder down
What behavioural uses do feathers have?
Courtship display,an territorial display, plucking down to line nest, brooding young
Name human uses for feathers
Down for pillows/duvets, fishing flies, feed protein
What happens when birds moult?
They moult their feathers in a strict sequence so they can always maintain the ability to fly (except waterfowl). The new feather pushes the old one out, blood and nutrients stay in the shaft until the feather is grown, then they are reabsorbed
What do birds use their tail for?
Balance for flying (lie a rudder), courtship displays etc.
Do birds have sweat glands?
No
What is a brood patch?
A featherless patch if skin on the underside of the bird, transfers heat to eggs better
Why is leg meat in older chickens red?
Because it is high in myoglobin
Name the bones in a wing
Humerus, radius, ulna, alula, fused metacarpals and digits
Name the bones in a leg
Femur, stifle, tibiotarsus, hock, tarsometatarsus (or shank), spur and digits
Function of sternum (breastbone)
Flying muscle attachment
Function of clavicle (wishbone)
Protects thoracic inlet
Function of caracoid
Stabalises flight muscles
Function of notarium
Fused thoracic vertebrae, for flight stability
Function of synsacrum
Stability for walking
Function of pygostyle
Support for tail
What do seabirds drink?
Seawater, they excrete salt out of salt gland dorsal to orbit which drains to nostrils where it is sneezed out.
Which us more important to birds? Texture or taste of food?
Texture
Why do birds have a GI tract with a low volume?
To reduce weight for flight
What is another name for the proventriculus?
The glandular stomach
What does the gizzard act as?
Teeth
What do birds excrete nitrogenous waste as?
Uric acid as semi-solid urates
Where is uric acid stored before being excreted?
In the coprodeum until faeces is voided
Name the 3 parts of the cloaca
Coprodeum (rectum), urodeum(ureters and genital ducts) and proctodeum
What does blood bypass during stress?
The kidneys
What is different about a bird’s lungs
They do not expand, air is pushed through them by airsacs
What ensures unidirectional airflow in a bird’s respiratory tract?
Valves and airsacs
When does fresh air pass over the lungs?
During inspiration and expiration
Many birds are sexually monomorphic, what does this mean?
The males and females look the same
What happens to the gonads prior to the breeding season?
The hypothalamus detects a change in day length, this causes an increase in GnRH, which in turn causes the pituitary gland to produce FSH/LH which initiates gonadogenesis
What sex chromosomes do birds have?
Males are xx and females are xy
In birds, which ovary is functional, and what happens if that one is damaged?
Only the left ovary is functional, if it gets damaged the right may begin to function as as a testis, she would look and act like a male, but still be genetically female
Name the parts of the ovary and oviduct
Follicles, infundibulum, magnum, isthmus, uterus/shell gland, vagina and vent
How often do chickens lay an egg?
Every 25 hours
Describe the production of an egg
A mature ovum (yolk) is shed from a ruptured follicle in the ovary into the infundibulum of the oviduct, where it is fertilised (15mins). Albumen (egg white) is added in the magnum (3hrs). Shell membrane is added in isthmus (1.5hrs). Shell and pigment is added in uterus (20hrs). 1 min in vagina
When does a hen ovulate?
30mins after laying, unless it is dark by then, then she skips a day
What factors can affect fertility?
Feeding, light levels, number of females to males
How long is incubation for chickens?
21 days
What is unusual about a bird’s RBCs?
They are nucleated
What part of the nervous system is larger in flying birds?
Bronchial plexus
What part of the nervous system is larger in terrestrial birds?
Lumbosacral plexus
Names identification methods for birds
Wing tags, poultry club closed rings and ring number can be tattooed under wing
