population dynamics

habitat

the environment where an organism lives and reproduces

Species

A group of similar organisms that can breed and produce fertile offspring.

population size

the total number of individuals within a defined area at a given time

population density

Number of individuals of the same species per unit area

crude population density

the number of individuals of the same species per unit area

ecological population density

Number of individuals of the same species per unit area actually used by the individuals

intraspecific competition

competition between members of the same species

Population

group of individuals of the same species that live in the same area

interspecific competition

competition between members of different species

density dependent factors

limiting factor that depends on population size

Examples of density dependent factors

competition, predation, disease

Density independent factors

limit population size regardless of the population density

Density independent factors examples

Natural disasters: fire, flood, earthquakes, climate change, tornadoes

fercundity

Average number of offspring produced by a female over her entire lifetime

types of growth patterns

exponential and logistic

exponential growth

Occurs under ideal conditions with no predators and unlimited resources (food, water, shelter, space). The population increases rapidly, resulting in a "j" shaped growth curve

logistic growth

Growth pattern in which a population's growth rate slows or stops ( plateaus) after a period of exponential growth as members compete for resources. S shaped

Ecological niche

This is composed of what an animal eats, what eats it, its reproductive method, temperature range, habitat, behavioural responses, and any other factors that describe its pattern of living

allele effect

a phenomenon in which the population growth rate decreases when populations reach small sized or low densities. When at low densities it becomes harder to find mates.

competition

the struggle between organisms to survive in a habitat with limited resources

Symbiosis

relationship in which two species live closely together

Mutualism

A relationship between two species in which both species benefit

Comensalism

Relationship where one organisms benefits, the other isn't effected

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Type I

Have very low mortality rates until they are beyond their reproductive years and have a long life expectancy's

Slow to tech maturity, produce relatively small numbers of offspring

Type III

most individuals die as juveniles, possibly even before hatching or birth. Only a few members live long enough to reproduce. They have a very low average life expectancy.

Type II

Curve that represents constant death rate over lifespan small animals and invertebrates. Like grey squirrels.

K-selected species

have a relatively long life span, become sexually mature later in life, produce few offspring per reproductive cycle, and provide a high level of parental care

r-selected species

Organisms with this strategy have short life spans, become sexually mature at a young age, produce large broods of offspring, and provide little or no parental care

Population dispersion

way in which individuals of a population are spread out over an area or volume

clumped dispersion

Organisms are densely grouped in areas of habitat with favourable conditions for survival

Uniform dispersion

individuals are evenly distributed throughout the habitat- may result from competition between individuals that do up territories for feeding, breeding or nesting

random dispersion

Random spacing of individuals of the same species within an area. It is a rare pattern in nature

mark-recapture method

A sampling technique used to estimate the size of animal populations. Capture, mark, release, recapture

quadrant sampling

A method of studying an ecosystem, where a representative, or group of representative square sections are selected. This is done when it is impossible to study an entire ecosystem "inch by inch"