ORNITHOLOGY FINAL

what influences male birds providing parental care?

altricial/precocial chicks, distribution + abundance of food, availability of females

monogamy

a single male mates and reproduces with a single female. may last for a single season or for life

polygyny

1 male mates with 2 or more females

polyandry

1 female mates with 2 or more males

extra-pair copulations

birds mate outside of their monogamous pair

polygamy

1 bird has 2 or more partners

why monogamy?

male assistance means higher # of chicks fledged from nest, males are mate guarding (preventing females from breeding with another male) or can't find other females to breed with

benefits of EPCs for females?

improved genetic quality of young - male partner needed to care for young, but females still continue to search for the highest quality male, fertility insurance (in case of male sterility), genetically diverse young

benefits of EPCs for males?

increased fitness, insurance against male's infertility

how do birds mate?

cloacal contact (waterfowl & ostriches are an exception)

when the ejaculates from two or more males compete to fertilize one female bird's ova

sperm competition

which bird ovary is reproductively active?

the left one bro

where do shell membranes get deposited?

isthmus

where does the egg get coated with albumen?

magnum area

where is the shell gland?

uterus

what is the total transit time for an egg

< 1 day

what requires embryo development?

heat, nutrients, oxygen

how does the embryo get oxygen?

micropores - holes in eggshell

benefit of incubation

prevents microbe infestation and water loss

when do eggs weigh the most?

immediately after laying (cuz moisture hasn’t been evaporated yet)

how much mass does an egg generally lose by the time it’s hatched?

15%

egg sizes are relative…

to the mass of the mother’s body

small birds lay eggs that are…

greater in relation to body mass, small birds will lay an egg greater than 5% of body mass while large birds will lay eggs less than 5% of body mass

are precocial eggs larger or smaller than altricial eggs?

generally larger due to the baby beign developed as hell

are yolks larger or smaller for precocial birds?

LARGER

do superprecocial chicks require longer or shorter developmental time in egg?

LONGER

why egg that color?

patterns make camouflage, variations allow eggs to be differentiated from each other.

what kind of patterns on egg?

spots, scrawls, lines

why blue egg?

females in better physical condition lay bluer eggs. maybe sign to males that chicks are worthy of investment?

why egg shaped like that?

flight needs and chick development pattern - egg shape correlates to species’ flight abilities

how is egg shaped measured?

ellipticity and asymmetry

2 types of brood parasitism

conspecific, interspecific

conspecific brood paratism (CBP)

parasitizing nests of the same species

interspecific/heterospecific (IBP)

parasitizing nests of different species

obligate BP

BP is the only way this species reproduces

facultative BP

some females parasitize some don’t

functions of nests

regulate temp, optimal location for heat transfer to egg, protection against predators

how do birds defend eggs against predators?

mob, physical attack, defecation/vomiting, concealment of eggs, distraction displays, false nest entrance

how do they be incubating?

body or sun (ex. megapodes, moundbuilders)

how they protect egg from heat?

favorable microclimates, shading by adults, wetting of eggs, burial + wetting

brood patch

bare patch to help the girl bird incubate produced by estrogen

how long incubation

10 days for passerine birds, up to 90 days in kiwi (so cute!) and albatross

optimal temp for embryo development?

37-38 degrees idk F or C probably C

incubation constancy increases as incubation progresses why?

too conserve fat reserves as egg grows

capital breeders

rely on stored energy reserves while nesting

income breeders

rely on daily foraging

what can influence incubation patterns?

ambient temperature, risk of predation

when is asynchronous hatching more common?

in altricial birds

how does chick hatch?

neck muscle and EGG TOOTH

what is brood reduction?

smaller chicks starve due to lack of resources

do altricial young grow much faster or slower than precocial young?

FASTER

berd chick scale

altricial → semialtricial → precocial → superprecocial

pretty easy huh?

in nesting, increaased flight proficiency means

higher more complicated nest

precocial chicks can regulate temp pretty well, guess who’s ass can’t

altricial chicks

who survives better big chick or little chick

big chick

natural history

refers generally to the lifestyle of an organism

life history

characteristics of an organism that
directly influence its fitness

life history characteristics evolve to maximize

lifetime reproductive success not annual
reproductive success

reproductive success varies…

with age, increasing and then leveling off - experience=success!

senescence

aging; happens to birds with long life expectancies

what determines clutch size?

number of young parents can provision with food

optimal clutch size…

balances offspring quantity and quality

how does breeding latitude effect clutch size?

clutch size increases

why the smaller clutch sizes with lower latitudes?

lower latitudes have more predation, longer breeding season, higher annual survival, more resources

nest types

scrape, mud nest, cup, platform, cavity, burrow