Exam 3

clutch

The number of eggs a bird lays in a set.

incubation period

The length of time required by embryos to develop between the laying of the egg and the emergence of the chick.

Both parents incubate

The most common situation in birds regarding incubation.

ZW

The sex chromosomes that a female bird has.

the 'direct benefits' hypothesis

The idea that females choose males with brighter red coloration because it indicates access to nutritious food for potential nestlings.

Nest predation

The most common cause of nest failure.

monogamy

The most common mating system in birds.

Functions of albumen

Helps moderate egg temperature and provides water for the embryo.

lek

An aggregation of displaying males.

fitness

Survival and reproductive output.

contest amount male birds

May result in characteristics that decrease survival but increase reproductive success.

Good genes hypothesis

Plumage and displays are a true genetic signal of fitness.

Arbitrary Choice hypothesis

Females may choose males not based solely on appearance but also territory.

Polygyny

A mating system where males control access to females by monopolizing resources.

Polyandry

A mating system where females mate with multiple males and each male tends a nest.

Polygynandry

A cooperative breeding unit formed by several females and males.

Brood Parasitism

Laying eggs in another bird's nest so those parents can raise them.

Kin selection

Helping relatives helps your own genes.

first mitotic division problem

Can result in a bird that is half male and female.

optimal development

Temperature range of 37-38 C for egg incubation.

brood patch

Bald patch on birds for incubation.

link between nests and hatchling abilities

The more defenseless the hatchling, the more elaborate the nests.

Altricial characteristics

Naked, blind, immobile hatchlings with large bellies and viscera for growth.

Precocial characteristics

Larger eggs with fuzzy or natal down in hatchlings.

superprecocial

Hatchlings that are wholly independent.

precocial

Hatchlings that leave the nest immediately and follow parents.

subprecocial

Hatchlings that leave the nest immediately but are fed by parents.

semiprecocial

Hatchlings capable of thermoregulating and mobile but stay in the nest and are fed by parents.

Behavior

Learned responses.

Innate responses

Instinctual responses.

Four important variables affecting bird reproduction

Age at first reproduction, fecundity, survival of young, and longevity.

Fecundity

The number of successfully raised offspring.

David Lack's theory on clutch size

Food limitation controls clutch size and the number of offspring negatively affects the survival of parents.