Avian/Birds Flashcards
describe avian bones.
bones are pneumatised- have air pockets, honey comb structure making the bones lighter but strong. their collarbone is also fused for stability
how are birds adapted? 8 adaptations.
STABILITY:
- fused vertebrate
- keeled sternum
- less bones
REDUCED WEIGHT:
- hollow bones
- less bones
- mandible
FLIGHT
- more neck vertebrate (groom feathers) = flight smooth
AIR CAVITIES
describe bird digestion.
- use tongue to move food to back of mouth and swallowed
- down oesophagus to the crop
- to the proventriculus, digestive enzymes & hydrochloric acid are added
- food moves to ventriculus (mechanical digestion)
- where large and small intestine join there are 2 ceca (water reabsorbed) & food fermented
- out the cloaca
function of the crop?
temporary storage area
what is removed through the cloaca?
mix of digestive waste and urinary waste removed in one substance
describe the oral cavity of birds.
birds beak = made of bone, keratin and blood vessels
they grow continually grow throughout life and worn down by grooming, feeding, climbing & rubbing
shape is adapted to type of food they eat. E.g., pelican has large lower beak for scooping fish
what type of vision does an owl have? describe it.
binocular vision- eyes overlap to create single 3D image
weakness - eye positioning = narrower field of vision
strength - better depth perception
components of the avian respiratory system.
- Nares (nostrils)
- Larynx (not for vocalisation - SYRINX is)
- Air Sacs (7-9 that extend into some bones)
- No Diaphragm (pressure changes through air sacs)
- Air Capillaires (gas exchange occurs)
what happens in avian ventilation?
- inhalation - air passes through larynx, trachea and into posterior air sacs
- exhalation - air goes from posterior air sacs, to lungs via ventrobronchi and dorsalbronchi
- inhalation - air moves from lungs to cranial air sacs
- exhalation - air moves from cranial air sacs through syrinx, trachea and out of nares
how many respiratory cycles do birds have?
2
components of bird excretory system.
- the ureters
- cloaca allows urine & other waste products to be cleared out of body
how do birds remove nitrogenous waste?
ammonia in the form of uric acid, no water required and is an insoluble substance
describe uric acid.
converted from nitrogenous waste, it is nearly non-toxic. uses more energy to make than urea, requires less water to produce meaning birds require less water in body and are lighter for flight.
what happens when the female reaches sexual maturity? female reproductive system.
the right ovary and oviduct degenerate leaving one functional ovary.
what happens to the ovary? female reproductive system.
it appears as a cluster which is composed of oocytes, then ovum (eggs) may develop over time. the ovum formation occurs from collection of lipid particles from blood forming the yolk.
what does the oviduct consist of? female reproductive system.
- infundibulum
- magnum
- isthmus
- uterus
- cloaca
what does the male reproductive system consist of?
testes
epididymis
vas deferens
papillae
cloaca
describe the phallus.
a copulatory organ which becomes inflamed with lymph during mating and allows semen to be deposited into the female.
what are androgens?
male sex hormones (e.g., testosterone) produced by the testes
what does androgen do?
responsible for the production of sperm and leading to sexual activity. they control secondary sexual characteristics.
what do eggs provide chicks?
environment & nutrition.
name & describe the structure of an egg.
shell - made of calcium carbonate and is hard to protect the developing chick, semi permeable for gas exchange, stops unwanted substances entering shell
inner & outer shell membranes -made up of proteins and lie between egg shell and albumen . they are an effective defence against bacteria
chalaza - spiral strand that holds the yolk in the egg white. there’s 2, chalazae
air cell - gap between the shell membranes
albumen - egg white, contains variety of proteins
yolk - yellow part of egg that provides food & nutrition for developing embryo
what are the four extra embryonic membranes?
- chorion
- amnion
- allantois
- yolk sac
what is fertilisation?
process starts with copulation, the male puts sperm into oviduct of female by depositing sperm from papillae to wall of females cloaca.
how long can sperm linger for in the females oviduct?
3 weeks but only have full fertilising ability for 6 days.
what’s the oviduct?
where egg is developed before it is laid, egg formed over 25 hours.
how long does the egg spend in each part of the oviduct?
infundibulum - 15 minutes
magnum - 3 hours
isthmus - 1 hour
uterus - 21 hours
cloaca - less than a minute
how many eggs can a chicken lay a year?
200-300
what are the incubation periods for chickens, pheasants, ducks, barn owls?
chickens - 21 days
pheasants - 23-24 days
ducks - 28 days
barn owls - 31 days
what is the incubation period?
period where the embryo is developed from the inside of the egg until it hatches.
what factors can affect egg production and why?
- availability of light - stimulates production
- food availability, diet &health - poor nutrition or health can cause a cease
- temperature - optimum egg temps are 11-26 degrees c, below or above that prevents production
- other factors such as breed, housing, husbandry, age, moulting, weather
what can under or overheating the eggs cause?
abnormal embryos developing
why is the humidity level important whilst eggs incubate?
having 60% the first 18 days and 70% for last days will prevent them drying out
why is ventilation important during incubation?
oxygen can enter cell which increases gradually when egg is about to hatch
why should you turn the eggs at least 3 times a day?
will stop the embryo sticking to the inside of the shell
what are the ureters in a avian excretory system?
2 tubes which carry urine from the kidneys to the cloaca
function of the cloaca.
allows urine & other waste products to be cleared out of body
what happens in the infundibulum?
receives egg & where fertilisation take place
what happens in the magnum?
secretes albumen
what happens in the isthmus?
adds shell membrane
what happens in the uterus?
secretes the shell & shell pigment
what happens in the cloaca?
where egg and waste products pass out
where are the testes located ?
abdominal cavity
what happens in the epididymis?
where the sperm is stored
where’s the vas deferens?
extended from the epididymis to the cloaca
what does the vas deferens do?
transport sperm
what does the papillae do?
emit semen into the cloaca of the female
what does the yolk sac membrane do?
digestive functions = food source for embryo & used by chick when hatched
what does the chorion membrane do?
surrounds embryo & allows gas exchange
what does the amnion membrane do?
forms sac to protect embryo & help hold amniotic fluid (shock absorber)
what does the allantois membrane do?
develops large circulatory system, allowing respiratory, excretory & digestive functions
