Lesson 20 - Geography and Ecology of the Cenozoic, Begin Extant Birds and Lesson 21 Flashcards
cenozoic ecosystem
- increasing isolation on continents from marine environments
- more and more isolating the freshwater bodies from other freshwater bodies
^^ see similarities that often result from convergent evolution
– early cenozoic was dominated by teleosts and the cartilagenous groip - penguins were also present as well as puffins (northern hemisphere)
- whales and dolphins and purposes
IN TERMS OF TERRESTERIAL
- most extant clades are from the cretaceous, so just before the cenozoic
- often refereed to as the age of mammals (cenozoic)
-^^ even thoguh mammals existed before, but they weren’t that diversified and were very small
tundra
- appeared in the pleiostecene
- also evergreen forest and deserts
the great american biotic interchange
- north and south america separated with the breakup of pangea
- those faunas developed in isolation
- isolating evolution of fauna in north america and south america
- before this – noth continents had herbivores and carnivores
- eutherians (placental mamamls)
- metatherians – masupeals (originated in south america as a group)
plateting primates
- known as the new world primates
- monkeys
- entered south america from africa in the early part of the senozoic
- got there we think by rafting – they were presumably on somthing – floating vegetation and eroding earth – the gap between the continent was not that wide
- there were no primates — all those niche spaces were available
- had an extensive radiation that old world primates do not have (the new world primates have tails to swing on)
isthmean pairs
- enjoyed passing back and forth between continential areas
- radiated in very similar patterns
- clades have evolved independently –> ex: the butterfuly fish
extinctions
- many were caused by himans
- only the last glacial period that brought the latest glacial extinction
- repeatedly we have interglacial periods where the glaciers recede and come again
why is it that the most recent glacial period had the most impact on the extinction of vertebrates (and not all many that have occurred before that_
– why has the most proximate cause been from humans
– humans weren’t moving around the world like they were in the earlier glacier periods
- so the movement came with a lot of extinction events as humans had advanced to parts of the earth that they haven’t been yet
birds
- around 11,000 species of birds – probabnly more than that
- flight does not characterize birds
- egg laying is present in all birds
- being dieurnal is in a lot of birds
- best trait to characterize –> feathers –> likely according to mos that some of the non-bird dinosaurs had feathers
- currently no stable robust phylogeny for the birds
pqleognathaw
lack a joint between the pterigoid and the palatine –> joint is fixed
neognathae
joint is a hinge between the pterygoid and the palatine
separation of the gallonanserae
chickens and dicks
pasoformies
- where approximately half f the known species are found
- song birds are not part of this
bird characteristics
- size has imposed a constraint on flight
- biggest flighted bird – california condor
- numitization of birds
- fusal of 10-23 caudal vertebrae
- pigeons overcome mass –> in part due to giant keel of sternum
keel of sternum
- associated with the powered flight of birds
- provides a surface area
- can’t have a powerful muscle that is small
- needs a lot of space to attach bones (hence the keel)
major flight muscles
- opposing muscles
- bicep relaxes while tricep relaxes (in humans)
- a muscle never pushes (except for tongue)
- generally have to be on opposite sides
UNIQUE - flight muscles are on the same side
- but this is allowed due to the tendon (pectoralisis and supraoforacoideus)
- key element for not being on opposite sides
– center of gravitt
– muscle needs to be big but it helps to keep the mass low - so this might have evolved to give the agile bird a lower center of gravity
feather tracts
- they don’t just cover the entire body
- feathers are located in certain patches
- big areas where there is no feather growth
- feathers grow in tracts
- since so many feathers spread out – it looks like they are covered in feathers
- most are betaketainin –
- ppigments give them color and can strengthen them
rackus
- central shaft
- barb extending off of the ruckus
(barbules extending out from the barbules (proximal and distal barbules))
preening
birds are restablishing the integrity of the vein on their feathers
- also preening applies oil
penacious feathers
- flight and protection
- like shedding water when it rains
a downing feather
- plumulacious feathers
- insulation
filopulmes
- sensory structures
- know the position of feathers
contor (double check tho)
- kind of combination of a downing and a contour feather
bristle feathers
used for screening out foreign feaathers
flight
understanding bird flight is problematic –> we still do not know a lot about how birds fly 00 we do know how they generate lift
—- bernoulli effect
cross section of the wing for flight and how they lift
- if you look at the leading edge — the distance over the wing from the leading edge to the trailing edge depends whether you go over the top or bottom
- air hits the front and has 2 ways of travelling (top or bottom)
- the ones on bottom are lagging
- end result is that the air molecules traveling over the top of the wing travel a little faster
- causes a pressure drop (faster moving molecules)
- net upward pressure
- SHAPE – cambor – that results in lift
wing loading volume
- mass divided by an area measure
- heavier birds have greater wing loading
- affects the power it needs to fly
bird hindlimbs
- ostrich has only 2 toes
- rhea - 3 toes - specialized in running
- secretary - 3 toes forward, 1 toe backwards
- roadrunner - 2 toes forwards, 2 toes backwards
feet for swimming
- do have a generally wide body through
- legs tend to be further shiften to the rear
- webbing isn’t always the same
- some birds have all 4 toes webbed
- others have lobed foot
— like paddles
— coolapse on themselves during forward strike
penguins
use their wigs exclusively for aquatic flight
diving petreles
wings are used for submarine and aerial flight
petrals
use wings exclusively for arial flight
evolution of wing use–»
a LOT of convergent evolution
syrinx
- analogous to our larynx
- at junction where trachea splits
- the 2 part pathway allows for 2 sounds to be made
beaks
- are not unique to birds
- but they have given rise to a tremendous amounts of diversity
- feeding
— offspring/mate
— grasp and transport things - offense/defense
- singing
skull kinetics in birds
- hinge jaw separates 2 groups of birds
distal rhynchokinesis
- long billed wading birds
– able to open parts of their bill up
– used when probing for worms in the sand
digestion: crop
- enlarged portion of the esophagus
- used for storage for food for young
- the young drink crop milk from the columnoforms
hormone for driving production of milk post bird
prolactin
- when a female gives birth, her prolactin levels shoot up
- it also stimulates parental care behavior
—- tips the balance between sexual behavior and parental behavior
discected foregut of the hoatzin + digesting cellulose
- they are one of if not the only truly herbiverous birds
– they don’t eat other birds/meat - more involved process than digesting meat
- plants have a cell wall
- no multicellular organism can digest cellulose
- animal cells have a cell membrane not a cell wall
- there is a lot of energy in cellulose that can be trapped into these certain bacteria
^^^^^ bacteria is able to digest it and (symbiotic relationship) and provide host with a lot of nutrients
gizzard
some hold stones
- intentionally ingest grit so it can properly ground up seeds
european starling
- change in the length of intestive vs. the amount of plant material in diet
- plant material is harder to digest, needs more surface area
tongue
- highly specialized in woodpeckers and in some surface feeders
- a muscle can only lengthen its length
- how is it that the hydrostatic muscle of the woodpeckers tongue extent so far
— the tongue wraps around the skull and even up through the naris
sensory systems + unihemispheric one eyed sleep
- most birds can see in the ultraviolet spectrum
- unihemispheric one eyed sleep
– they sleep with half their brain awake
– because they are delicious and make excellent prey
– the ones at the end of the row of ducks spend more time with their outside eye open
– scanning for predators
– they also hooked up EeGs and monitored sleep
-
sexually monomorphic
- meaning that by eye humans cannot tell the difference between male and female birds
- birds can tell via ultraviolet light
- we may see a black bird but they may see a colorful bird
we are trichromatic
- birds have a 4th cone cell – used for detecting this ultraviolet scale
olfactory
- barely have any kind of olfactory bulbs
- however turkey vultures have exceptional olfactory bulbs
- black vultures mostly use vision and follow turkey vultures
hearing
- minute details of a bird’s song can be made out and detected
- birds have approximately 10X as many hair cells in their cochlear that enhances resolution
barn owl hearing
- shape of head abd parabola is used for picking up on sounds
- collecting and amplifying sounds
- ex::: like a staellite
- concentrates sound into a narrow space
^^^^ concentrates sounds along radius –> function of facial disk
owls
- left ear is further from the right ear
- difference in timing of arrival of sound allows them to target prey very precisely
mating systems
- monagamy is probably the primary one
- social monagany – pair forms and they raise a child (not necessarily genetic monagamy)
polyandry
female mates with more than one male
polyamery
male mates with more than one female
when you have a socially bonded pair–»
extra pair relationships
- 10-40% of the babies being fed by that male are not his (depending on the species)
- males can sire more offspring
- being polyamorous increases your fitness (as a male)
—- one of the females you are mating with may be infertile
sexy son hypothesis
- argument for why females might mate with another male
- if the tendency is for males mating w a non primary mate, then maybe her own male offspring may carry that allele and her offspring could have that trait – may have a higher probability of being promiscuous
sex role reversal in sandpipers
- female does lay egg but..
- males build the nest, incubte the young, feeds the young
- males are the choosier sex and they choose between the flashier sex
colorization of feathers
- plumage
- carrotanoits
– pigment that produces a red/orange/yellow color - convey a heatlh benefit
– known to be an antioxidant
– protects from oxibdative metabolism
—- this does damage to the cell
—- supress aging by supressing damage to DNA
– female prefer to mate with the brighter, darker, deeper colored male
- reflects the physiological ability of the males
- beter fittness for having capacity for antioxidants
sounds
- can be learned
- both males and females learn them
– but it is normally the males that produce hem
^^^^^ learned vocalization of songbirds
6 species that learn their vocalizations
songbirds, parrots, hummingbirds, humans, whales/dolphins, bats
origin of vocal learning in vertebrates
occurred independently 6 times
song repertoire
- song control regions of the brain
- ratio of brain regions between males relative to females
zebrafinch: song repertoire
- constitue 4X the volume in males to females
rens: song repertoire
- approaches 1:1
- why are they roughly equal in who sings
^^^ striking difference in male and female brain - these control regions get large in the spring and smaller when not in spring
^^^ aduly neurogenesis
oviperous
- do not think that oviparity evolved for flight
- dates quite a ways back
- 15 avian families that are flightless
— bats have flight but they give live birth
endothermic
may have evolved for warming of the brood
birds display nesting behavior
- can be quite variable
– bald eagle –> enourmous structure
– coots will float their nests on the pond/lake
– some species use the heat of composting vegetation
^^^^^ embryo only develops when it reaches the proper temerature “critical developemnt point”
avian ovary
there are a bunch of primordial follicules
- all different size
- offset each by a day
relationship in latitude and clutch size
- higher latitude –> higher clutch size
- lower lattitudes are more succeptible to pathogens and microbes
– at incubation temperatues – those microbes are killed
photoperiodic
- use seasonal changes as a timing/cure for annual events
- they reproduce in the spring – use cues
photoperiodic cues
- photoperiody changes when you get from the equator
- at the equator - 12 hours. daylight and 12 hours of night
- changing light exposure per day causes release of hormones that drives reproduction
- some of the best photoperiodic work is done by plants
- if you keep birds on a certain photoperiod they will not develop gonats
- long days drive them into the breeding state
how does photoperiody work
- photostimulation detectd by brain
precocial
- advanced for your age
- can have feathers, beak, functioning eyes
altricial
- humans are like this
- not developed
- larger gut
precocial – eggs
because they are hatching at a much more advanved stage, the egg has more yolk in it
ultimate talk about photoperiody
reason we get migraptry behavior in birds
- is it because they can identify different pulls of energy
zugunruhe
migratory restlessness
- ^^ never displayed in nature – only in laboratory
- when you have them in a cage at a time when it wants to migrate – it will get restless
- it hops trying to get out and migrate
- the vast location of ink blots were at certain locations
fall - southern location
spring - northern location
