Population Ecology and Demography

Demography

Study of population size and structure changes.

Cohort

Group of individuals born at the same time.

Life Table

Summarizes survival and reproduction probabilities.

Survivorship

Percentage of cohort surviving to a specific age.

Mortality

Percentage of cohort dying in a given year.

Fecundity

Number of offspring produced by an individual.

Survivorship Curve

Graph showing survival rates across ages.

Type I Curve

High survivorship early, rapid decline later.

Type II Curve

Constant decline in survivorship throughout life.

Type III Curve

Low early survivorship, high later survivorship.

Age-specific Fecundity

Average female offspring produced at a certain age.

Net Reproductive Rate

Survivorship multiplied by fecundity across age-classes.

Population Growth Rate

Determined by net reproductive rate calculations.

Life History Traits

Organism's energy allocation for growth and reproduction.

Life History Trade-off

Balancing growth, reproduction, and maintenance.

High Fecundity

Associated with low survivorship in species.

Low Fecundity

Associated with high survivorship in species.

Immigration

Arrival of individuals into a population.

Emigration

Departure of individuals from a population.

Survivorship Data

Used to create survivorship curves for analysis.

Population Change

Analyzed through life tables and survivorship.

Cohort Tracking

Following a cohort over several years.

Population Crash

Dramatic decline in population size.

Reproductive Output Peak

Time of highest reproduction in a species.

Energy Allocation

Distribution of energy for growth and reproduction.

Natural Selection

Process influencing survivorship and fecundity.