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Biol 444 Final Exam Study Guide
The exam will be based on these points here, plus abstracts from the papers you read.
This is a lot to know, but if you can answer all of these points, you’ll be good to go.
Origin of Birds
Why was Archaeopteryx an important fossil find?
What were 3 traits it had in common with modern birds? What traits were different? How
do we know it probably flew.
What is the strongest piece of evidence that birds didn’t evolve from Thecodonts? What
are some lines of evidence that birds evolved from Theropods?
Which Theropod lineage did birds come from and what is one famous dinosaur found in
the lineage?
Prum: What does the ground –up vs. trees-down debate have to do with the Thecodonts
vs. Theropods debate? Thecodonts were arboreal—and if flight evolved trees down, then
it makes sense for birds to come from Thecodonts. Theropods were bipedal ground
dwellers. Freeing the arms would have been an important step towards flight…etc.
What are the closest extant (living) relatives of the birds? (crocodilians)
Feathers and Flight and early bird evolution:
What were the two major classes of Cretaceous birds that went extinct at the KT
boundary?? How would you recognize each of these?
What are some examples of Tertiary birds? What were they like?
What did the earliest feathers look like?
What are some functions of feathers in extant and extinct birds (besides aiding flight?)
What do Ken Dial’s experiments in WAIR tell us about the origins of flight and the use
of proto wings (that were not developed for true flight)? Very generally, what did he do,
and what were his results? (check the physiology PPT notes for more info on this)
How do birds get lift? What are the forces acting on a wing or generated by a wing that
lead to flight?
Physiology:
What are some advantages to having high body temp?
What are disadvantages and how do you deal with it? (overheating, how do you avoid it?)
What is a major similarity and a major difference between bird and mammal hearts?
What is a major difference between avian and mammal blood?
Compare and contrast avian and mammal respiratory system.
What are 3 things birds can do to deal with cold?
How do hummingbird tongues work?
Endocrine and territoriality:
What are the important annual life history stages?
What is the major environmental regulator of the annual cycle? What is light acting on in
the body?
What is the major hormone secreted in the testes of male birds at the onset of breeding?
What are the major physiological functions of T? What are a few of the major side effects
of T? What are consequences of T for males that are implanted with extra T?
When does plasma T increase and when does it decrease relative to the stages of
breeding?
How do T levels differ in arctic sparrows (like a longspur) vs. temperate sparrows (like a
song sparrow)? How again to they differ in a tropical year round territorial Passerine?
How, very generally (non-technically), might territoriality be maintained in the absence
of high plasma T?
T is synthesized directly in the brain from DHEA as needed, thereby reducing the costs of
maintaining high plasma T.
Endocrine and Stress:
When is cort good and when is it bad? What does it do for birds? Why is cort higher in
males than females? What do you think? What did authors think? This is an evolving area
of research. Either females chronically stressed and can’t mount stress response, or they
are just less stressed because they are fitter overall. We really don’t know. What do we
know is the consequence of sustained elevated cort seems to be bad for females’ RS.
Males may be more stressed out, but seem to be parenting OK (at least in White crowns,
but maybe not in spotted owls).
Migration and Navigation:
No that there are many different types of migration, and be prepared to talk about them. I
don’t care if you remember the terminology for the types.
Pros and cons of migration
What environmental cue triggers migration? Photoperiod and weather. Note that this may
not be true for tropical birds migrating latitudinally or altitudinally, although some
tropical birds are sensitive to small changes in daylength. Changes in food availability
may influence altitudinal migration in the tropics.
Is migration controlled by genes or learning? What are some ways we know this?
Describe the classic blackcap study.
What are 3 ways we know bird migration routes?
Why do some populations within a species use different migratory routes? Why do some
species migrate north one way and south another way?
What are 5 major cues birds use to navigate? How do we know this?
What is the major “fuel” birds use for flight?
Brain and Senses:
Compared to reptiles birds have larger optic lobes and smaller olfactory lobes
Which groups have largest cerebellar lobes? Why? What is the cerebellar lobe not
associated with?
What is hippocampus associated with? What are some examples of cases where birds
need good spatial memory?
What is the typical technique for understanding what parts of the brain control what, or
how developed certain parts of the brain are for birds that behave one way vs. those that
behave another way? (killing, staining for gene expression, slicing, and dicing)
What part of the brain controls vocal production (HVC = higher vocal center). Note that
HVC can change size seasonally and is expressed differently in male vs. female song
birds.
What about smell? Small olfactory lobes in birds. Which birds have well developed
smell—name two orders…
How might odor be involved in mate choice? Odor is clue to MHC allele type
Bird eyes vs. mammal eyes: bigger, no blood vessels (pecten in stead), UV vision (in
some cases), many more cones. Nictitating membrane. Why are these traits important?
How does hearing range of birds compare to mammals? Sounds must be louder to be
detected outside of 1-4 khz optimum range.
Beecher:
What is the function of song repertoires in male song sparrows? Sex and real estate, but
more complicated than that too. Complex system of mediation of aggression. Check the
slide with the flow chart on matching, type matching, etc. Why is it important to know
your neighbor and how do you recognize him? How do you know if he is a “bad”
neighbor (what made him “bad” in the experiment, and what were the consequences to
the “bad” neighbor)?
Communication and Signals:
Pros and cons of aural and visual signals.
Why not be as loud as possible?
What kinds of sounds travel best in different habitats? Frequency, complexity?
Reasons for using signals
Status signaling and mate attraction: Sender should bluff (why?) Receiver should discern
(why?). What happens to bluffers (experimentally darkened Harris sparrow males)?
Punished. You have to walk your talk or you get punished as other males begin to test
you. The size of your black patch correlates with your actual status (ability to be
aggressive—correlates with T too).
Why might females be attracted to larger song repertoires in some species?
What to song sparrow females listen for in repertoires?
What do dee notes correlate with in chickadee alarm calls? What does predator wing
span have to do with anything?
Bird Mating Systems and sexual selection:
Why should females be more choosy than males in mate choice?
What is the handicap principle? Why would females like signals that are costly to
produce? Give some examples.
How is the runaway model different? No cost to the trait initially. In fact it’s usually an
adaptive trait to start with. It’s just a genetic linkage between trait and preference for trait
that ends up exaggerating the trait more and more over each successive generation. Don’t
need to know more than that for this class. Peacocks may be an example.
What are ecological conditions leading to monogamy?
What are the advantages to social monogamy with promiscuous breeding? What do males
gain? What do females gain? How should males behave in systems like this?
When would a female redwinged blackbird rather pair with a male who already has a
mate?
What happens in polyandry? Reverse sexual dimorphism…females defend territory, male
builds nest on female’s territory, he raises offspring, etc.
Sneaker males and female-like plumage in males
Brood parasites: How did this evolve in cowbirds?
Why lekking? No resources to defend because they are ephemeral in space and time.
Consequences of lekking? Rapid selection for extreme behaviors because extreme skew
in male RS. Only one or a few guys get to mate. The next generation looks like him.
Cooperative Breeding:
What are some reasons a bird might forego breeding and help someone else breed?
Do helpers actually help or just hang around? How do we know? What happens if you are
a bad helper?
Study slides 16, 17, 18.
Social Behavior:
What are some examples of how indirect interactions (e.g. observations of others’ direct
interactions) are important in birds?
What are two incentives males might have to join leks and display as a beta or nondominant male (other than the fact there are no resources to defend). Think about kin
selection in the case that males are related and social networking in the case they are not.
Other examples of social behavior? Networking in Seatte’s crows?
Think about the Ani paper that was assigned. Perhaps relates more to cooperative
breeding. Why are Ani’s in groups successful? Why do you join a group? What do you
do if you are a dominant or subordinate female? Why?
Don’t mistake with non-social interactions (with other species). For example army ants
and antbirds—this is not social. Antbirds are parasitizing army ants (taking their prey
from them). Or oxpecker and cows. Oxpeckers do pick ticks off cows but they also suck
cow’s blood! Not to mention these are, again, two different species.
Birds on Islands:
What is the physical climate like on islands (stable/mild) and what is the social/ecological
climate like (low predators/ long life/ habitat saturation/high competition)? What kind of
reproductive strategies should this lead to? K selection—read conclusions slide to refresh
your memory on what this should select for and what has been found by surveying
studies of island birds.
Habitat fragments: Kiran’s PPT and paper (review abstract of her paper), and read my
notes on McArthur-Wilson theory.
Tropical/Temperate Life history:
Why should we care more about studying tropical birds? Diversity is there. Can we
generalize about all birds given most studies are based on temperate birds?
What is unique about the tropics? Reduced daylength cues, reduced seasonality, lower
densities of food and conspecifics (other birds in your species), higher nest predation.
What does this mean for birds that live and breed in the tropics? How should they behave
differently from temperate birds?
Speciation and Hybridization:
Many groups of birds seem to be on the verge of speciation (e.g. song sparrow races). But
is the geographic variation in song sparrows heritable? Probably, but no one has done the
best test of this. What do you need for speciation? Adaptive divergence in traits,
divergence in mating signals (can be selected for if hybrids between two populations are
unfit—song divergence helps prevent production of hybrids)[ remember tinkerbird
example]. Divergence in mating signals alone (without adaptive divergence) probably not
enough (think white crowned sparrow dialects). Physical barriers to geneflow are even
more helpful.
At least 10% of birds not “good species” under BSC
Many diverged populations/species will collapse back into one. Think about Townsend’s
and Hermit Warblers in WA. Diverged in separate refugia in the last ice age. Now habitat
is contiguous again. See notes.
Darwin’s finches are not “good species” under BSC. But function as species because of
song divergence and assortative mating by song.
Crossbills. Why don’t they just merge back together? They encounter each other. Call
types keep them apart and hybrid matings making offspring that aren’t adapted to any
particular cone type…See Torie and Johnny’s article.
WA bird habitats:
What are some important habitats in WA and threatened and characteristic species in
each? Why are the species you thought of threatened? How do you define the habitats?
Important vegetation or features of each habitat? Moisture gradients and gamma
diversity.