Cuntsack Crocodiles + Bum Birds

Foramen of Penizza

Extra valve in crocodilian heart that stops deoxygenated blood from going to lungs and instead sends it around the body. Might be useful when underwater or to aid in digestion

Apetum Lucidum

Reflective surface at back of eye which makes eyes glow and enhances night vision.

Quill/Calamus

Hollow base part of feather

Rachis

Shaft of feather

Barbs

Rows of parallel branches in feathers

Barbules

Small branches on barbs that stiffen feather by interlocking togehter.

Papilla

Outgrowth of skin that turns into a feather

Vane

Part of feather that is made of barbs and barbules

Alula

Free-moving first digit on hands that is used in flight to prevent stalling and create lift during slow maneuvers.

Uropygial Gland

Produce waxy substance that makes birds water resistant

Preening

Spread oils around body from Uropygial Gland. Also important for scent.

Beaks

Bone + Keratin, only keratin can regrow. Basically a replacement for hands.

Salt Glands

Located near nostrils, secrete extra salt

Synsacrum

1. an elongated composite sacrum containing a number of fused vertebrae, present in birds and some extinct reptiles.It provides structural support and aids in flight.

Keel

Extension of sternum where wing muscles attach. Provide support and leverage.

Pygostyle

Fused vertebrae at the posterior end of birds.

Bird Heart

4 chambers, 40% larger relative to body size when compared with mammals, left ventricle more muscular.

Rete Mirable

Means “wonderful net”

Net of closely aligned arteries and veins mainly found in the feet.

Uses countercurrent exchange to flow warm and cool blood against each other and conserve heat in extremeties.

Flightless Birds

Birds probably evolved flightless because large birds need a bunch of energy to fly. Also no need to fly in islands and shit.

Terror Birds

Lived 40-1mya, ate meat, fast runners, apex predators in south america, 3-9ft tall..

Swimming Birds

Ducks: Skim surface or tip upside to feed underwater; tails remain above water. •

Cormorants: Agile divers; long beaks with hooks, large webbed feet.

Penguins: Streamlined, flipper wings, webbed feet; cannot fly; denser bodies helps to reduce buoyancy.Birds adapted for aquatic life, using various techniques for foraging and movement in water.

Pectoralis

Pulls wing down, breast muscle

Supracoracoideus

Pulls wing up, muscle.

Bird Respiration

2 inhales 2 exhales.

First inhale: air to posterior air sac
First exhale: air from posterior air sac to lungs
Second inhale: air from lungs to anterior sacs
Second exhale: air from anterior sacs out.

100% replacement of air

No diaphragm, uses costal breathing - expanding rib cage

Syrinx

Bases of trachea in birds

Can make 2 different sounds at the same time, allowing them to make a variety of sounds.

Produces tones while larynx modulates tones.

Songs

Find mates, compelx, defend territory, specific to speciesC

Calls

Not sexual in nature, simpler, used to coordinate behavior like foraging/avoiding predators.

Bird Brain

Highly developed for problem-solving, evolved differently from mammals.

Pallium

Uppermost layer of vertebrate brain

Analagous to mammal cerebral cortex

Higher level thinking, example of convergent evolution.

Crop

Modified part of esophagus where bird stores some seeds that act as emergency rations.

Digestion

Gizzard to hold gastroliths to grind up food in absence of teeth.

Eyes

Best vision of all animals.

Monocular vision = both eyes are used separately. Prey birds like pigeons got this.

Binocular vision = narrow field of view but good depth perception.

Asymmetrical eye, flattened back forms a larger screen, gives long focal length, images appear bright on the retina • Birds can change their focal distance very rapidly through changes in the curvature of the cornea • Ciliary muscles change the shape of the lenses • Lenses much softer than mammal • They move their cornea by drawing the edges backward and increasing the curvature

Birds have 4 cones so they can see UV light.

High speed birds like hawks have 2 fovea which allow them to focus on small prey.

Double to 4x as much density of photoreceptors vs humans.

Pecten

Blood rich structure that gives nutrients to bird eyes so that blood vessels don’t take up a bunch of space.

Anchored to optic disk.

Allows birds to see in fast-changing conditions.

Oil Droplets

Oil droplets in cones filter light that may be distracting when hunting prey.

Tapedum Lucidum

Reflective layer behind retina that enhances night vision. Found in nocturnal mammals.

Sclerotic Ring

Layer of bones in the eyes of birds, turtles, lizards, fish. Maintain eye shape and focus eye muscles. Counter water pressure.

Columella

Single bone in inner ear.

Facial ruff

Stiffened feather on owls that amplify outside sound by up to 10dB.

Ears

Asymmetrical, allow them to recognize where sound is coming from.

Brood patch

Area of featherless skin on underside of body