Birds Vertebrate Zoology. Thecodontosaurus Thecodontosaurus

BirdsBirds

Vertebrate Zoology

ThecodontosaurusThecodontosaurus

ThecodontosaurusThecodontosaurus

IguanodonIguanodon

IngeniaIngenia

IncisivosaurusIncisivosaurus

ArchyopteryxArchyopteryx

150 mya

ArchaeopteryxArchaeopteryx• Possible link between birds & reptiles

• Large skull with reptile like teeth

• Bones not hollow

• Claws on forelimbs

• Long tail

• Strong legs & rounded wings for gliding

• Feathers

• Furculum - fused collarbone or wishbone

HesperonisHesperonis

Fossils 75 mya• Large, flightless

bird• Had teeth like

reptiles

IchthyornisIchthyornis

• Smaller, tern like bird

• Lived 65-80 mya• Had large flight

wings

Evolution of BirdsEvolution of Birds

• Evolved from reptiles

• Few fossils due to lack of preservation of feathers or thin, hollow bones

Bird CharacteristicsBird Characteristics

• Endothermic• Feathers = modified scales• Pectoral appendages = wings• Pelvic appendages = feet• Crop & gizzard• Air sacs & lungs• Counter-current circulation• Uric Acid excretion• Sexual reproduction

Characteristics pg 2Characteristics pg 2

• Feathers made of protein called keratin• Thin, hollow bones; some bones fused for extra

strength• Scales on legs• Toothless, horny beak• Additional air sacs with lungs for more oxygen• Four chambered heart• Amniotic egg with calcium carbonate shell• Oviparity with both parents often caring for

eggs

EndothermicEndothermic• Warm blooded

• Ability to generate heat & maintain a constant body temperature

• Can live in hot or cold climates

• Requires more food

• Requires faster body processes to generate heat

FeathersFeathersUsed in many ways• Flight

• Regulation of body temperature (thermoregulation)

• Protection of the body

• Attraction of mates

• Identification of species

FeathersFeathers

• Modified scales

• Provide lift for flight & help conserve body heat

Types of FeathersTypes of Feathers• Contour feathers

cover the body of a bird and have a strong, hollow shaft and network of hooks.

• Down feathers are small and are located under the contour feathers to insulate the bird from the cold.

Feather AnatomyFeather Anatomy

• Rachis – stiff “backbone” of feather

• Barb – branch off of rachis

• Barbule – connect barbs

• Calamus = Quill

Contour FeathersContour Feathers

• Flight feathers = remiges

• Tail feathers = retrices • Act as brakes and a rudder• Most birds have 12 tail feathers

Contour FeatherContour Feather

Lacking Barbules in Owl Lacking Barbules in Owl Feathers = Quiet FlightFeathers = Quiet Flight

PreeningPreening

• A bird spends part of each day making minor repairs to tears in its feathers

• Feathers are re-zipped

Preening Zips the FeathersPreening Zips the FeathersBefore After

Feather GrowthFeather Growth

Down FeathersDown Feathers

• Soft & fluffy

• Cover the body of nestlings

• Provide an undercoat insulating adult bird

FiloplumesFiloplumes

• Called pin feathers

• Hairlike feathers under contour feathers on body

WingsWings

Flight ForcesFlight Forces

Bernoulli’s PrincipleBernoulli’s Principle

Keeled Sternum and Keeled Sternum and FurculumFurculum

Thermals & Air CurrentsThermals & Air Currents

Feet Feet

Digestion – Digestion – Crop & GizzardCrop & Gizzard

Woodpecker & Woodpecker & Honeycreeper TonguesHoneycreeper Tongues

RespirationRespiration

Counter-Current Counter-Current CirculationCirculation

Excretion – Uric AcidExcretion – Uric Acid• Uric acid

metabolic excretion

• (Saves water)• Urea• Ammonia

Reproduction Reproduction

CloacaCloaca

Egg ShapesEgg Shapes

Starling NestsStarling Nests

Weaver Bird NestWeaver Bird Nest

Brood ParasitismBrood Parasitism

Cardinal or Cowbird eggs?

MigrationMigration

Bird BrainsBird Brains