10 - Birds 2 Flashcards
Endothermic
create their own body temperature and regulate it
What makes endothermy and flight possible
high metabolic rates
What kind of animal has the highest rate of oxygen consumption
birds
Bills and tongues and moveable heads
highly modified for a wide variety of feeding habits because no front limbs other than wings
Bills reflect what they do. Ex: ripping apart prey, catching prey in water, breaking up nuts and seeds, filter feeding, pecking trees
Woodpecker
has a tongue so long it wraps around its skull while not in use. Used to get bugs out of trees
Hummingbirds
have a tongue with a lamella and supporting rod to suck up nectar
Digestive tract
crop: storage
stromach:
- proventriculus - secretes gastric juices
- ventriculus (gizzard) - muscular, for grinding
Heart and circulation
- separated atria and ventricles = separate pulmonary and systemic circuits
- sinus venosus = patch of tissue in right atrium serving as pacemaker
- rapid heart rate
What kind of breathing do birds do to be efficient
unidirectional lung ventilation
Our type of breathing
tidal ventilation
Unidirectional lung ventilation
- air sacs
- parabronchi
- continuous movement of oxygen rich air over respiratory surfaces during inspiration and expiration
Respiratory cycles
2 cycles of inspiration and expiration
- inspiration: air goes from bronchus to abdominal air ascs
expiration: goes to parabronchi - inspiration: into thoracic air sac
expiration: out of body
Thermoregulation of feet on ice
Counter-current exchange
Warm blood goes toward cold foot but transfers heat to cold blood coming from foot before it gets there so that no heat is lost and warm blood in vein goes back up to body
Just enough heat reaches feet to keep them from freezing
Heat conservationi
- fluffing feathers to decrease heat loss
- tucking bill into feathers
- countercurrent heat exchange in legs
Heat generation
Shivering
muscular activity in flight
Osmoregulation
marine birds drink only salt water and kidneys need help. So sea birds have a salt gland, salt gland duct and tube nostril to secrete salt
Egg formation in birds
- egg is ovulated into ostium
- travels through the oviduct
- magnum adds first layers of albumen
- isthmus adds inner membrane and outer shell membrane and albumen
- the shell gland adds albumen, shell, pigments
- leaves through vagina then cloaca
Reproduction in birds
- oviparous
- left ovary develops and releases eggs to large ostium
- Albumen secreted by oviduct
- shell gland secretes shell around fertilized eggs
Mating in birds
Most are monogamous
Territories and courtship are common
Some are polygynous
Some are polyandrous
Some young are altricial while some are precocial
Monogamous
stay together all of their lives, one partner
Polygynous
territorial males defending up to 10 females who only mate with 1 male
polyandrous
females mate with more than 1 male
Altricial young
entirely dependent on parents at birth. Endothermy not developed
Precocial young
more alert/independant. one parent is usually present though (ex: ducks)
