birds vertebrate zoology. thecodontosaurus thecodontosaurus
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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