Exam 1: Diversity

Feathers

• insulation

  • control of body temp, activity, endurance

• novel structure

• extensions of feather on forelimbs and tails led to flight

bird services

• consumers of insects

• pollinators of flowers

• dispersers of seeds

  • particularly in the tropics

  • good for secondary succession

• barometers of ecosystem health

  • just like macros

conservation perspective

• need to consider the bird’s entire year

  • migration, stops, winter, nonbreeding season

basic characteristics (8)

• bipedal vertebrates

• backbones

• feathers

• bills

• entirely structured for flight

• balance on land

• power in water

• arboreal species

basic characteristics: feathers

• soft, filamentous, flexible, lightweight

• dead structures

  • need regular replacement

• essential for temp regulation and flight

• generating lift and thrust

basic charactersitics: bills

• toothless

  • special digestive system

    • gizzard

  • reduces weight

• horny sheath

• no parallel among other verts 

basic characteristics: enterily structured for flight

• bones 

  • lightweight, spongy, strutted, hollow

• added strength from fusing bones together

  • in hand, head, pelvis

• uncinate processes

  • strengthen walls of body

  • projection off of rib bones

  • adds stability

  • little pointy jaws off of the rings, perpendicular 

• furcula

  • wishbone

  • powerful spring responding to bind beats

basic characteristics: balance on land

• center of gravity is directly over feet

• equal length of tibitarsus and tarsometetarsus 

  • top and bottom part of leg

basic characteristics: power in water

• foot-propelled diving birds

  • sacrifice balance for speed

  • loons

• powerful legs situated at the rear of a streamlined body

basic characteristics: aboreal species

• majority of birds

• have feet that grip tightly

• tendons automatically flex when the bird squats

• locking the toes around the branch

  • highly developed in passerines

physiology

• red meat

  • flight muscles

  • capacity for sustained work

  • can shiver

    • gets them warmed up enough to fly

• endothermic

  • maintain high body temps

  • 40C or more

• four chambered heart

• efficient lungs

• eggs

  • richly provisioned external eggs

  • paternity

    • eggs in a clutch can have multiple fathers

• brains

  • large, well developed

  • highly develop neural system

    • communication, navigation

how many birds on earth?

• ~300 billion birds on Earth

  • we have a fraction currently of what we used to have

extreme variety

• 40 orders

• 247 families

• 2312 genera

• ~10,699 species

birds started to diversify in form and function came with opportunities

• due to adaptive radiation

  • evolution of additional varied species adapted to different ecologies and behaviors

• bill size and shape changes according to food

• leg length change in relation of perching and terrestrial locomotion

• wing shapes change in relation to patterns of flight

  • open habitats

    • long, pointed wings

  • trees

    • stubby, rounded off

life histories

• birds diversify in all aspects of their season and social behavior

  • repro rate

  • lifespan

  • age of maturity

life histories: albatrosses

• 1 egg at a time

• life for a long time

life histories: songbirds

• large clutch sizes

• short life span

life histories: other variables

• egg size in relation to body size

  • ducks

    • for the mass of a duck, they produce more egg volume than others generally do

• agility of new chicks

  • wood duck chicks 

• degree of parental care

  • male humming birds

    • deadbeats

natural selection and convergence

• evolutionary adaptation through natural selection

• the fit of form and function is the driving force of avian diversity and life-history traits

natural selection

the predictable predominance of individuals with advantageous traits

finch bill size

• galapagos

• Peter and Rosemary Grant

• extreme drought

• no new seeds

  • only large seeds persisted

convergence

• the independent evolution of similar adaptation in unrelated organism

• coming together to share a trait despite not being related

• demonstrates natural selection well

• adaptation to similar ecological roles causes unrelated species to become superficially similar in appearance and behavior

meadowlarks and longclaws

• ML

  • grassland specialist 

• LC

  • african

  • grassland specialist

• not related

• look very similar

• grassland plumage

auks and penguins

• penguin

  • southern hemisphere

• auks

  • look awfully similar to penguins 

biogeography

• wallace is the father of biogeography

• study of geographical distributions of plants and animals

• 6 major faunal regions

  • neartic

  • neotropical

  • palearctic

  • afrotropical

  • indomalayan

  • australasian

    • each has characteristic birds

    • endemic taxa or species

what two places do you need to know?

• neartic

• neotropical