Density-Dependent Limiting Factor Quiz and Flashcards

Why do density-dependent limiting factors usually not affect small, scattered populations?

How do density-dependent limiting factors affect birthrates and death rates?

Why is competition considered a density-dependent limiting factor?

How does the inability to establish and defend a territory impact breeding success?

Why is competition for territory important among animals?

What is a major force behind evolutionary change as mentioned in the text?

Why are parasitism and disease considered density-dependent limiting factors?

What effect can overcrowding stress have on some species according to the text?

How can constant fighting in some species affect the body's ability to resist disease?

What is one consequence of overcrowding stress mentioned in the text?

Limiting Factors

Density-dependent limiting factors operate more strongly when population density is high and do not usually affect small, scattered populations.
Examples of density-dependent limiting factors include competition, parasitism, disease, stress from overcrowding, predation, and herbivory.

Competition

Competition is a density-dependent limiting factor that occurs when individuals compete for limited resources such as food, water, space, sunlight, and other resources.
As a result, competition can decrease birthrates, increase death rates, or both.
Animals compete for territory to access resources, attract a mate, breed, and raise young.
Individuals that can’t establish and defend a territory often cannot successfully breed and raise offspring.

Parasitism and Disease

Parasitism and disease are density-dependent limiting factors that spread more easily in dense host populations.
Parasites and disease-causing organisms weaken their hosts, causing stress or even death.

Overcrowding and Stress

Overcrowding can cause stress, weakening the body’s ability to resist disease.
In some species, overcrowding stress can lead to females neglecting, killing, or eating their own offspring.
Overcrowding can lower birthrates, raise death rates, or both, and increase rates of emigration.
In some species, overcrowding can lead to fighting, which can result in death or stress.

Learn about density-dependent limiting factors that operate more strongly in high population densities. These factors, such as competition, parasitism, disease, overcrowding stress, predation, and herbivory, affect large populations more than small, scattered ones.