Scientific Connections Exam 2 - Pruett

Two major flight muscles

Pectoralis and Supracoracoideus

Pectoralis job

Produces downstroke of the wing, main power stroke for flight

Supracoracoideus job

Responsible for lifting the wing during upstroke, important for takeoff (especially in birds that require strong lift)

Bernoulli Effect

Air moving over a wing travels: faster over curved top and slower below the wing; slower air below the wing pushes upward more strongly than faster air above which creates lift

Newton's Third Law

For every action there is equal and opposite reaction (push air downward, air pushes bird upward)

Angle of attack

angle between the wing and the airflow

Angle of attack effects

Increasing the angle increases lift, if angle becomes too steep > airflow separates from wing causing stall and lift decreases

Two types of drag

Pressure induced drag and Friction profile drag

Pressure Induced drag

Caused by airflow separating from the wing; produces vortices that disrupt lift

Friction Profile drag

Caused by air rubbing against the wing surface

Three things that affect drag

Mass, Flight Speed, Wing Surface Area

Mass and Drag

Heavier birds experience more drag

Flight Speed and Drag

Faster speed increases drag

Aspect Ratio

Wing length/wing width (describes wing shape)

High aspect ratio

Long narrow wings, efficient soaring, less drag (ex is albatross)

Medium/high ratio

High speed flight (ex is falcons and swifts)

Low Aspect Ratio

Short broad wings, better maneuverability (ex is songbirds and quail)

Gliding

Wings extended, no flapping, bird slowly loses altitude

Soaring

Using rising air currents to stay aloft, no wing flapping necessary

Two types of soaring

Thermal and Dynamic

Thermal soaring

Uses rising warm air

Dynamic soaring

Uses wind differences over the ocean

Flapping flight

Wings move up and down, produces thrust and lift

Hovering

Birds remain in one place (ex is hummingbirds) most energetically costly flight

Downstroke

Wing moves downward and forward, generates thrust and lift, called the power stroke

Upstroke

Wing partially folds, feathers separate to allow air through, reduces drag (recovery stroke)

Flap Gliding

Bird alternates flapping and gliding, more efficient at slow speeds, common in larger birds

Flap Bounding

Bird alternates rapid flapping, wings folded briefly, more efficient at high speeds, common in smaller birds

Cost of slow speeds

Most costly

Cost of moderate speeds

Least costly

Cost of very fast speeds

Intermediate costs (hovering extremely costly)

Function of Air Sacs

- move air through the lungs

- improve oxygen efficiency

- reduce body heat during flight

- lighten body weight

Function of Syrinx

Produces bird sounds and songs

Syrinx

Bird's vocal organ, located at the base of the trachea where it splits into the bronchi

Path of Two Breaths through Avian Respiratory System

Air moves through system in two breathing cycles; system keeps fresh air moving through lungs continuously

First inhalation

Air enters > posterior air sacs

First exhalation

Air moves > lungs

Second Inhalation

Air moves > anterior air sacs

Second exhalation

Air leaves body

Similarities of bird vs mammal cardiovascular systems

- both have four chambered hearts

- both have separate pulmonary and systemic circulation

Differences of bird vs mammal cardiovascular systems

Birds:

- hearts are larger relative to body size

- higher heart rate

- higher metabolism

Three ways birds deal with too much heat

- panting

- gular flutter (rapid throat movement)

- feather positioning to release heat

Three ways birds deal with too little heat

- shivering

- fluffing feathers to trap heat

- increasing metabolism

Three ways birds maintain water economy

- water from food

- metabolic water produced during metabolism

- drinking free water when available

How birds excrete Nitrogen

As Uric Acid

Differences in Nitrogen excretion from mammals

Birds:

- produce uric acid

- requires little water

- appears as white paste

Salt Balance

Seabirds have salt glands near their eyes; function is to remove excess salt from seawater and salt leaves through nasal openings

Seed Eaters

Thick bills

Nectar feeders

Long narrow bills

Meat eaters

Hooked bills

Filter feeders

Specialized bills

Woodpeckers

Long barbed tongues

Hummingbirds

Tubular nectar tongues

Fish eaters

Simple tongues

Order of food thru digestive system

- buccal cavity

- esophagus

- crop

- proventriculus

- gizzard

- small intestine

- large intestine

- cloaca

Differences between bird and mammal digestive systems

Birds have these which mammals do not:

- crop

- proventriculus

- gizzard

- cloaca

Other differences between bird and mammal digestive systems

Birds perform chemical digestion first, then mechanical grinding in the gizzard

Functions of crop

- temporary food storage

- some birds produce crop milk

Functions of proventriculus

- glandular stomach

- chemical digestion using enzymes and acids

Functons of gizzards

- muscular stomach

- grinds food with swallowed grit

Function of small intestine

nutrient absorption

Function of large intestine

water absorption

Functions of Cloaca

Common chamber for:

- digestion

- reproduction

- excretion

Differences between bird and reptile brains

Bird brains:

- larger

- more complex

- greater cognitive ability

- more developed learning and memory regions

Similarities between Bird and Human brains

Both have:

- advanced learning centers

- problem solving ability

- complex social behaviors

- advanced memory systems

Why "Bird Brain" is incorrect

Phrase implies birds are unintelligent; bird brains have complex cognition, memory, communication abilities, and tool use

Functional Lateralization

Different sides of brain specialize in different tasks (ex is one eye watches for predators, other searches for food)

Episodic memory

Ability to remember what happened, where, and when; important for birds to store food

Unihemispheric sleep

Birds can sleep with half their brain while other stays awake; purpose it to watch for predators and maintain flight during migration

Hippocampus function

- spatial memory

- navigation

- remembering food caches

(birds that store food like chickadees have larger hippocampi)

Examples of bird intelligence

- tool use

- problem solving

- food caching

- cooperative behavior

- communication

Communication intelligence example

Parrots learn and mimic language

Food caching intelligence example

Chickadees remember thousands of storage sites

Tool use intelligence example

Crows use sticks to extract insects

Problem solving intelligence example

Birds solve puzzles to obtain food

Dynamic Soaring

A flight technique where birds use differences in wind speed over the ocean to gain energy and stay aloft with little wing flapping.

Plumage

The feathers that cover a bird's body, including their arrangement, color, and pattern.

Crop

A food storage pouch in the esophagus where birds temporarily store food before digestion.

Corvid

A member of the crow family (Corvidae), including crows, ravens, magpies, and jays, known for high intelligence.

Glide Ratio

The distance a bird can travel forward while losing a certain amount of altitude during gliding.

Counter-current

A heat conservation system where warm blood flowing from the body transfers heat to colder blood returning from extremities, reducing heat loss.

Proventriculus

The glandular stomach of birds where chemical digestion begins using acids and enzymes.

Cache

A stored supply of food hidden by birds to eat later.

Formation Flying

Birds flying in organized patterns (often a V formation) to reduce energy use by taking advantage of air currents from other birds.

Hypothermia

A state where a bird's body temperature drops below normal levels, often to conserve energy.

Gizzard

The muscular stomach that grinds food mechanically, often using swallowed grit or small stones.

Wingtip Vortex

Spiraling air currents created at the tips of wings during flight, which can influence lift and drag.

Torpor

A temporary state of reduced body temperature, heart rate, and metabolism used by some birds to conserve energy.

Bursa of Fabricius

A specialized immune system organ in birds where B cells develop.

Air Sac

One of several thin-walled sacs in the bird respiratory system that move air through the lungs and improve oxygen efficiency.

Frugivore

An animal that primarily eats fruit.

Central Nervous System (CNS)

The brain and spinal cord, responsible for processing information and controlling the body.

Heart Rate

The number of heartbeats per minute, which determines how fast blood circulates.

Insectivore

An animal that primarily eats insects.

Peripheral Nervous System (PNS)

The network of nerves outside the brain and spinal cord that carries signals between the CNS and the body.

Stroke Volume

The amount of blood pumped by the heart with each beat.

Nectarivore

An animal that feeds mainly on nectar from flowers.

Olfaction

The sense of smell.

Gular Fluttering

Rapid vibration of the thin floor of the mouth/throat used by birds to cool themselves and release heat.

Ramphotheca

The keratin covering of a bird's bill (beak).