BirdsBirds

TaxonomyTaxonomy

Kingdom AnimaliaKingdom AnimaliaPhylum ChordataPhylum ChordataSubphylum VertebrataSubphylum VertebrataClass AvesClass Aves

Key TermKey Term

The study of birds The study of birds is called is called Ornithology.Ornithology.

Origin of BirdsOrigin of Birds

Most scientists agree that birds evolved Most scientists agree that birds evolved from a group of early reptiles.from a group of early reptiles.

Bird fossil records are incomplete due to Bird fossil records are incomplete due to lightweight/delicate skeleton.lightweight/delicate skeleton.

ArchaeopteryxArchaeopteryx is the earliest and most is the earliest and most primitive bird ever found – fossil had teeth, primitive bird ever found – fossil had teeth, long tail, hind wings, and feathers.long tail, hind wings, and feathers.

Archaeopteryx Archaeopteryx is considered a transitional is considered a transitional fossil between dinosaurs and birds.fossil between dinosaurs and birds.

Modern BirdsModern Birds

~ 9000 species~ 9000 species Divided among 27 different ordersDivided among 27 different orders

Compared to 3 orders of amphibians and 4 Compared to 3 orders of amphibians and 4 orders of reptiles.orders of reptiles.

Similarities to ReptilesSimilarities to Reptiles

1. clawed toes1. clawed toes2. scales on their feet2. scales on their feet3. internal fertilization 3. internal fertilization 4. shelled amniotic eggs4. shelled amniotic eggs

Differences from ReptilesDifferences from Reptiles

4-chambered heart4-chambered heart endothermic – maintains constant body temperatureendothermic – maintains constant body temperature respiration – air sac – 75% of air goes into air sac respiration – air sac – 75% of air goes into air sac

and 25% goes in to lungsand 25% goes in to lungs no teethno teeth have feathershave feathers have a beak or bill, which is a keratinized extension have a beak or bill, which is a keratinized extension

of their bony jawof their bony jaw feet adapted for swimming, grasping, and perchingfeet adapted for swimming, grasping, and perching

FeathersFeathers

A A featherfeather is a lightweight, modified scale that is a lightweight, modified scale that provides 1) insulation and 2) enables flight.provides 1) insulation and 2) enables flight.

Also plays role in Also plays role in courtship, incubation, and courtship, incubation, and waterproofingwaterproofing

PlumagePlumage – the covering of feathers on a bird. – the covering of feathers on a bird. PreeningPreening – process of cleaning and rubbing oil on – process of cleaning and rubbing oil on

the feathers to keep them waterproof and in good the feathers to keep them waterproof and in good flying condition, also gets rid of parasites.flying condition, also gets rid of parasites. Ruffled feathers need smoothing with the bill so barbules Ruffled feathers need smoothing with the bill so barbules

re-connect.re-connect. A preen (oil) gland is usually located above the base of A preen (oil) gland is usually located above the base of

the tail.the tail.

FeathersFeathers

MoltingMolting – shedding of a few old feathers – shedding of a few old feathers w/the growth of new onesw/the growth of new ones

flight and tail feathers are usually lost in flight and tail feathers are usually lost in pairs as to maintain balancepairs as to maintain balance

do not molt at critical times such as do not molt at critical times such as breeding, migration or food shortage breeding, migration or food shortage (drought)(drought)

Different types of feathersDifferent types of feathers

3 Types of Feathers3 Types of Feathers

1.Down feathers1.Down feathers2.Contour feathers2.Contour feathers3.Filoplume feathers3.Filoplume feathers

1.Down Feather1.Down Feather

Down feathers Down feathers --Insulation & Insulation & waterproofing waterproofing feathers - common in feathers - common in young birds; fluffy young birds; fluffy w/no barbs (hooks w/no barbs (hooks that interlock their that interlock their filaments)filaments)

found underneath the found underneath the contour feathers.contour feathers.

2. Contour Feathers2. Contour Feathers

Contour feathers Contour feathers – most – most common; gives body common; gives body shape; used for flight; shape; used for flight; sleek, streamlined sleek, streamlined

Specialized contour Specialized contour feathers found on wings feathers found on wings and tail; contains and tail; contains barbules that stay barbules that stay together and move air.together and move air.

3. Filoplume Feathers 3. Filoplume Feathers

Filoplume feathers Filoplume feathers – long, – long, thin shafts w/weak barbs thin shafts w/weak barbs and barbules, found and barbules, found around beaks.around beaks.

They are believed to have They are believed to have a sensory function, a sensory function, helping birds keep their helping birds keep their feathers in order.feathers in order.

Parts of a FeatherParts of a Feather

ShaftShaft – continuation of – continuation of quill, bears numerous quill, bears numerous barbsbarbs

BarbsBarbs – branch off into – branch off into barbules which overlap barbules which overlap w/adjacent w/adjacent barbs/barbules with the barbs/barbules with the ends interlocking, ends interlocking, keeping feathers firm keeping feathers firm and smoothand smooth

QuillQuill – hollow; emerges – hollow; emerges from skin folliclefrom skin follicle

ColorColor

Some color is a result of Some color is a result of pigmentspigments, other , other colors called colors called structural colorsstructural colors, result from , result from irregularities on the surface of the feather irregularities on the surface of the feather that diffracts white light.that diffracts white light.

Color patterns are involved in species Color patterns are involved in species and sex recognition and sexual and sex recognition and sexual attraction, as well as provide camouflage.attraction, as well as provide camouflage.

ColorColor

Pigment ColorsPigment Colors MelaninMelanin produces black, brown, and tan produces black, brown, and tan CarotenoidsCarotenoids produce red, orange and yellow produce red, orange and yellow

Structural colorsStructural colors blue and green feathers – barb reflects blue blue and green feathers – barb reflects blue

wavelengths of light, other wavelengths pass wavelengths of light, other wavelengths pass through the barb and are absorbed.through the barb and are absorbed.

white is the complete light reflectionwhite is the complete light reflection iridescence results from interference of light iridescence results from interference of light

waves caused by the flattening and twisting of waves caused by the flattening and twisting of barbules.barbules.

Adaptations for Flight…Adaptations for Flight…

1. have feathers1. have feathers 2. front appendages modified as wings2. front appendages modified as wings

wing shapes vary- some adapted for soaring and wing shapes vary- some adapted for soaring and others for short quick flightsothers for short quick flights

3. 3. endothermicendothermic- helps to 1) maintain high energy - helps to 1) maintain high energy levels necessary for flight 2) inhabit a variety of levels necessary for flight 2) inhabit a variety of habitats (tropics to Antarctic)habitats (tropics to Antarctic)

4. high metabolic rate – eats large amounts of 4. high metabolic rate – eats large amounts of food to maintain energy levelsfood to maintain energy levels

5. vertebral column modified for flight – long, 5. vertebral column modified for flight – long, flexible neck allows for bill and neck to function flexible neck allows for bill and neck to function as a third appendageas a third appendage

Adaptations for FlightAdaptations for Flight 6. air spaces in the bones – sturdy, thin, hollow 6. air spaces in the bones – sturdy, thin, hollow

bones; strengthened by bony crosspieces with air bones; strengthened by bony crosspieces with air spaces;spaces;

7. sternum w/keel – sternum (breastbone)-where flight 7. sternum w/keel – sternum (breastbone)-where flight muscles are attachedmuscles are attached

8. four-chambered heart – rapidly moves oxygenated 8. four-chambered heart – rapidly moves oxygenated blood, bringing needed oxygen to cells quicklyblood, bringing needed oxygen to cells quickly

9. efficient respiration - 2 cycles-when bird exhales, 9. efficient respiration - 2 cycles-when bird exhales, oxygenated air passes from sacs into lungs – birds oxygenated air passes from sacs into lungs – birds receive oxygenated air when they breathe in and out; receive oxygenated air when they breathe in and out; heat also carried away w/water vapor in the air that is heat also carried away w/water vapor in the air that is exhaled.exhaled.

10. digestive system that is adapted to deal w/large 10. digestive system that is adapted to deal w/large amounts of foodamounts of food

How Birds FlyHow Birds Fly

1. Lift of the wings must overcome bird’s 1. Lift of the wings must overcome bird’s weight.weight.

2. Forces that propel bird forward must 2. Forces that propel bird forward must overcome drag that bird moving in air overcome drag that bird moving in air creates.creates.

Wings provide propulsion.Wings provide propulsion. Tail provides balance, steering, and Tail provides balance, steering, and

breaking.breaking.

Types of FlightTypes of Flight

1. flapping flight1. flapping flight 2. gliding flight – common in seabirds 2. gliding flight – common in seabirds

(albatross)(albatross) 3. circling3. circling 4. hovering – common in birds of prey 4. hovering – common in birds of prey

(falcons)(falcons) 5. soaring – use rising air currents over heated 5. soaring – use rising air currents over heated

land or beside cliffs; eagleland or beside cliffs; eagle 6.diving – may be for hunting, mating, warnings6.diving – may be for hunting, mating, warnings

2 Groups of Birds Based on 2 Groups of Birds Based on Ability to FlyAbility to Fly

1. 1. PaleognathaePaleognathae – large flightless ostrich- – large flightless ostrich-like birds, Kiwis – have a flat sternum with like birds, Kiwis – have a flat sternum with poorly developed pectoral muscles; poorly developed pectoral muscles; descended from flying birds – evolved to be descended from flying birds – evolved to be large because their weight did not matter.large because their weight did not matter.

2. 2. NeognathaeNeognathae – flying birds that have a – flying birds that have a keeled sternum on which powerful flight keeled sternum on which powerful flight muscles attach.muscles attach.

(Birds can also be grouped by feeding habits)(Birds can also be grouped by feeding habits)

FeedingFeeding

Birds have no teeth – swallow small Birds have no teeth – swallow small stones that help grind food in the stones that help grind food in the gizzardgizzard..

Lack bony jaw – reduces weight.Lack bony jaw – reduces weight. Have a beak/bill that is adapted to their Have a beak/bill that is adapted to their

food source.food source. CropCrop is the storage structure for food, is the storage structure for food,

allows for consumption of large quantities allows for consumption of large quantities of food.of food.

Bills

SensesSenses

Acute sense of hearing Acute sense of hearing and vision.and vision.

Birds have large eyes Birds have large eyes relative to body size.relative to body size.

ReproductionReproduction

Life cycle – (reproduction usually takes place in Life cycle – (reproduction usually takes place in spring) Times vary with species and size of birdsspring) Times vary with species and size of birds

Example: WarblerExample: Warbler Nest construction - 4 to 5 daysNest construction - 4 to 5 days Egg laying – 5 to 7 daysEgg laying – 5 to 7 days Incubation – average 11 days (albatross 80 days)Incubation – average 11 days (albatross 80 days) Fledgling – 9 to 12 days (hatchling to departure of Fledgling – 9 to 12 days (hatchling to departure of

young)young) Lifespan can be 5 years for some warblers, up to 30 Lifespan can be 5 years for some warblers, up to 30

years for some species (herring gull). Typically, the years for some species (herring gull). Typically, the larger the bird, the longer their lifespan.larger the bird, the longer their lifespan.

Attract mates with colors, songs or calls.Attract mates with colors, songs or calls.

Chick care…Chick care… Altricial Altricial - Young - Young

are entirely are entirely

dependant on dependant on

parents at birth.parents at birth. Precocial Precocial - Young can care for - Young can care for

themselves at birth. Eyes open themselves at birth. Eyes open with downy feather covering.with downy feather covering.

2 Types of Mating2 Types of Mating

1. 1. monogamymonogamy – 1 partner per breeding – 1 partner per breeding season; 90% of all birds exhibit this season; 90% of all birds exhibit this behavior; female needs male to set up behavior; female needs male to set up and defend territory, find food, provide and defend territory, find food, provide prenatal care; some swan/geese species prenatal care; some swan/geese species have 1 mate for life.have 1 mate for life.

2. 2. polygamypolygamy – 2 or more partners per – 2 or more partners per breeding seasonbreeding season

MigrationMigration

MigrationMigration – innate behavior; follow the – innate behavior; follow the food; fly south around September, food; fly south around September, triggered by length of daylight hours; return triggered by length of daylight hours; return early spring.early spring.

Migration allows birds to avoid extreme Migration allows birds to avoid extreme climate changes and to secure food and climate changes and to secure food and shelter.shelter.

Arctic terns fly up to about 40,000 miles/yr. Arctic terns fly up to about 40,000 miles/yr.

Causes of ExtinctionCauses of Extinction

1. habitat destruction1. habitat destruction 2. collecting bird parts, such as feathers, 2. collecting bird parts, such as feathers,

beaks, talons, pet tradebeaks, talons, pet trade 3. lead poisoning3. lead poisoning 4. toxic effects of pesticides, oil spills, 4. toxic effects of pesticides, oil spills,

and chemical dumpingand chemical dumping 5. competition by introduced species 5. competition by introduced species

(cats, rats, mongoose, rabbits and goats)(cats, rats, mongoose, rabbits and goats)