Ornithology Final

Genetic basis of migratory behavior

pop of some species can take different routes

expirment showed f1 offspring migrated same way while hybrids mediated

senses used for migration

• olfacotry cues

• sun

• stars

• magnetic field

• visual landmarks

types of social behavior

• territoriality

• dominance hierarcheis

• colonies

• flocking

solitary

raptors are usually

pairs

songbirds and ducks are usually

gregarious

shorebirds are usually

family groups

coop breeders are usually

when benefits outweigh the costs

• health of offspring

• inc fittness

• energy lost

• inc predation risk

• death

territorality arises when

2 classes of territory

• breeding

• non-breeding

breeding territories

• size often cor w/ bird size

• breeding/courtship purposes

• nesting

• food

• size could depend on resources

  • less resources = bigger

  • vice versa

• swallows territory = just their nest

• defend the area to protect against cuckolding

lek

communal display ground where only alpha male gets copulation.

(prarie grouse, woodcock, bird of paradise)

roosting territory

nocturnal security, murmurations

feeding territory

often nectar feeders defend large feeding site against others

territories should be economically defendable

energy avalible in a territory should not be less than energy expanded in defense of territory.

personal space territory

groups perch together but still remain distanced

coloniality

response to shortage of safe nesting sites or abundant/unpredicatable resources that are not worth defending

occurs often in seabirds

benifits to group living

• saftey in numbers

• pred detection

• mobbing

• pred sampling

predator sampling

all babies born at same time = less chance ur baby gets got by pred

wintering communal roosts

bald eagles roost together in winter for why?

Information center hypothesis

costs of group living

• depletion of resources

• inc intraspecific comp

• loss of paternity

• attract pred

• disease

flocking

• aggregation outside of breeding

• flock feeding = info sharing, cooporation, more comida yum yum yum

• mixed spp flocks

  • common in tropics

  • exist in NA too, think cardinals titmice, chickadees

  • hierarchy w/in mixed spp flock

  • often shared distinct plumage

caraco et al 1980

optimal or intermediate flock size due to tradeoffs between feeding, fighting, scanning for pred

birds w/ dick (cloacal phallus)

• ratities

• caracids

• waterfoul

• kiwis lost it

• intermetiant organ special modification of the ventral wall of coloca

• explodes in air??

teste size breeding stratagy specific

larger in spp that breed colonially than those who breed solitarily

inc sperm comp

inc breeding density associated with

bird sperm

acrosome w/ axial filimant, midpiece, nucleus, and tail membrane,

• males release 1.7 to 2.5b per ejaculation (8b possible)

• females can store for 10 days to 5 weeks

protoporphyrn pigment from hemoglobin

egg strength is derived from

egg resource strat

lots of food → more eggs but smaller egg size

less food → less eggs but bigger size

pyriform egg shape

• pelagic birds

• more SA per vL

• more gass exchange??

• egg rolls in circle not off cliff

• more resistant to impacts

Egg laying

• usually 1 laid per day or every other day

  • penguins 3-6dy

• 1st and last eggs tend to be smaller in size

• younger birds lay smaller eggs avg

egg process

reproductive anatomy

intrasexual selection

male-male comp

intersexual selection

mate choice

anisogamy

many small sperm vs few eggs means inital investment of female in offspring is larger

ebbinghaus illusion

bowerbirds create forced perspective w gesso to attract mates and make their treasures look larger

male traits as cues

• color

• size

• tail length

• symmetry

• song

• display rate

• courtship feeding

male quality cues

• disease resistance

• survival

• nutrition

• development

• parental care

good genes hypothesis/good health hypothesis

suggests that individuals with desirable traits signal their genetic fitness, leading to better offspring survivability.

why isnt the trait selected to fixation

• variation in female choice

• condition dependance of male traits

• multiple traits at play

lek paradox

lesser males do not get copulations so why dey do dat

3 lek models

• hotspots

  • m gather where f are likely to be

• hotshots

  • lesser m gather around top dawg for even 00.1% chance of mating

• female preference

  • f preffer to visit large clusters of m

EPP (Extra Pair Paternity)

young sired by male other than the females social pair mate

• only 14% of socially mono birds are genetically mono

• uncommon in pirds of prey

polgynandry

males and females getting it on w everyone songbirds (maybe only in jims head but hes a dreamer)

polgyny

one male many females, arises when resources are abundant and f can raise offspring alone

RWBB

male benifits EPP

• more offspring

• parasitize paternal care

• spread risk due to predation

Male EPP costs

• providing care to unrelated young

female EPP benefits

• inc gen var in young

• inc quality of young

• inc access to resources

• fertiliy insurance (jim thinks no silly)

• sperm comp

Female EPP costs

• STDs

• dessertion by primary male

HYP for varation in EPF

• breeding synchrony

• breeding density

• genetic variance

polygyny threshold

why f mate w/ mated m and not unmated?

certain benefits outweigh the costs like territory quality is better in older males than unmated

predictions of polygny

1. male territory quality will be correlated with mating success

2. or female should be compensated by sharing territory other female for sufficient benefit

3. more common in patchy envi (more var in qual)

resource defense polygny

females chose high qual territory not neccesarily male

polyandry

• one f many m

• m does parental care

• reverse sex dimorphism

• common in shorebirds

• high var in f success

• some raptors

brood parasites

• faculative (blackbirds) or obligate (YBCU, BHCO)

• originated from egg dumping

• only 1 precosial bird (black headed duck in Africa)

• originated twice in passeriformes

  • new world cowbirds

  • african finches

• three origins in Old World and New World cuckoos

  • cuculina

  • phaenicopanadiae

  • Neomorphinae-Crotophaginae

• single origin in Old World honeyguides

Farming Hyp

Brood parasites destroy host spp nest so they are forced to relay the nest and the parasite can then lay her own eggs in there

arms race between parasites and hosts

• parasitic spp develop faster in the nest

• bee-eater has ‘killer tooth’ to kill foster siblinings

• parasites mimic egg patern/ gape pattern (Vidua family)

• hosts may use hatch order to determine parasites (coots)

• songbirds nest away from edges where parasitism risk is highest

mafia hypothesis

parasites kill your babies to ‘threaten’ hosts into raising their young

Cooperative Breeding

• Helping non-offspring appears to be altruistic

• Helpers benefit others while incurring costs

• Cooperative Groups

• > 200 species of birds

• 3% of bird species

Helpers at the nest

• 80% of coop breeders

• breeding pair plus 1 or more younger indivuals

• ex: florida scrub jay, harris hawks, bell miner

plural breeders

• multipule nests within colony

• ex: groove billed anis, galapagos hawks

why is coop breeding so rare

requires some form of delayed dispersal and benefits of family must outweigh costs

delayed dispersal

• ecological constraints model

• caused by scarcity in breeding vacancies

• stay in parents territory untill vacancy opens

benefits of cooporative breeding

• familiar territory

• survival improves

• parents benefit from help

• offspring benefit from help

• helpers gain indirect fitness ( and offspring? )

costs of cooporative breeding

• drain on territory resources

• helpers forgoe breeding although capable (lose direct fitness)

absolute fitness

number of offspring that survive and reproduce

relative fitness

absolute fitness of one individual or genotype compared to another

inclusive fitness

direct fitness and indirect fitness

do helpers exist because of ecological consstraints or because indirect fit outweighs direct

• hamiltons solution

• kin selection

hamiltons solution

inclusive fitness = own contribution + relatives contribution / average contribution of population

B x r > C

Or rearranged…

C/B < r

Where:

B = fitness benefit given to a recipient

C = fitness cost to actor (self)

r = coefficient of relatedness

Kin Selection

Direct component

• Production of own offspring

Indirect component

• Pass on your genes by enhancing

the reproductive success of

relatives

• r = coefficient of relatedness

factors affecting helping

• habitat selection

• kin selection

testes inc with

increasing clutch size