Intraspecific Competition

True/False: Populations grow indefinitely.

False, every population confronts the limits of the environment

The exponential model of population growth, dN/dt = (b − d)N, is based on what assumptions?

Assumes that essential resources (space, food, etc.) are unlimited and that the environment is constant

          This is not typically the case

How does the environment stray from our assumption for the model of population growth?

The environment is not constant and resources are not unlimited

As the density of a population increases, demand for resources ________.

increases

If the rate of consumption exceeds the rate at which resources are replenished, then the resource base will ______.

shrink

Shrinking resources and the potential for an unequal distribution of those resources results in…

Increased mortality and fecundity

Density-dependent effects influence a population in proportion to its ____.

Size

An environmental factors or something that affects the population regardless of the number of individuals, the influence is said to be….

Density independent

What is the function of density-dependent effects?

To slow the rate of population growth by increasing mortality and decreased fecundity

True/False: Competition always exists.

False, as long as there are plenty of resources to satisfy all organisms there will be no competition

Define scramble competition.

When growth and reproduction are depressed equally across individuals in a population as the intensity of competition increases

Define contest competition.

Takes place when some individuals claim enough resources while denying others a share

True/False: Generally, under the stress of limited resources, a species exhibits only one type of competition.

True, but some practice different types of competition at different times in a life cycle

True/False: In an extreme scramble competition, all individuals may receive insufficient resources for survival and reproduction leading to local extinction.

True

True/False: In an extreme contest competition, all individuals may receive insufficient resources for survival and reproduction leading to local extinction.

False, there are some individuals who successfully compete and survive to sustain the population

True/False: Individuals always compete directly with each other for resources.

False, they often end up responding to the depression of resources, not directly interacting with another individual

Define exploitation.

Individuals take up a majority of resources leaving little behind for others to use with little interaction between the individuals

Define interference.

Individuals interact directly with one another, preventing others from occupying a habitat or accessing resources within it.

What does intraspecific competition first affect in a population? Survival and reproduction? Or growth and development?

Growth and development

How is growth and development affected in intraspecific competition?       

Depressed resources means that there is less growth and development

Describe density-dependent growth.

An inverse relationship between population density and individual growth

Define self-thinning.

A progressive decline in density and increase in biomass (growth) of remaining individuals caused by the combined effects of density-dependent mortality and growth within a population

As a population reaches a high density, individual living space can become more ______.

restricted

As a population reaches a high density, aggressive contacts among individuals…

increases

Define pheromones.

They are perfume-like chemical substances that are produced and released into the environment by an animal that affect the behavior or physiology of other individuals of its species

What can trigger hormonal changes that affect individuals within an population?

Stress (due to less food, shelter, or other resources)

Instead of coping with stress, some animals…

disperse

True/False: Dispersal is a regulatory mechanism.       

False, it does not usually affect population size to a large degree

True/False: Social behavior is a regulatory mechanism.

True, it can limit the number of animals living in a particular area

Define territory.

The area an animal defends

Define home range.

The area that aan animal normally uses during the year

In general, carnivores require a (smaller/larger) home range than herbivores and omnivores of the same size.

Larger

Describe the Allee Effect.

A form of inverse density dependence, where at low population size, birthrate declines or mortality increases; and below some minimum population density, the rate of population growth is negative

When would the Allee Effect take place?

In species where they are widely dispersed and cannot find a mate, especially when the population density is very low

Define minimum viable population (MVP).

The number of individuals necessary to ensure the long-term survival of a species

Define minimum dynamic area (MDA).

The area of suitable habitat necessary for maintaining the MVP