Bis 2B Week 4: Community Ecology Predator_Prey

What is community ecology

The study of interactions among multiple species living together in a given location.

What are interspecific interactions

interactions occur between different species,

What are intraspecific interactions

Occur within the same species

Define Amensalism

An interaction where one organism is harmed and the other is unaffected

Define commensalism

An interaction where on organism benefits and the other is unaffected.

Larger plants shade smaller plants: is this an example of amensalism or commensalism?

Amensalism

Define mutualism

An interaction where both participating organisms benefit

Define predation/parasitism and give its effects on both species

An interaction where one organism benefits at the expense of the other

Define competition

An interaction where both species are negatively affected due to shared limited resources

What is the Lotka-Volterra Model used for in predator-prey dynamics?

Mathematically models how predator density affects prey population growth, and how prey density in turn affects predator population growth, often producing coupled population cycles.

What is a Type I Predator functional response?

A linear increase in prey consumption rate as prey density increases, with no saturation limit (rare in nature except at low densities)

What is a Type II predator functional response?

Prey consumption rate increases rapidly at low prey density but levels off at a high density due to predator satiation and handling time.

What is predator satiation

An evolutionary strategy of survival where prey briefly emerge or reproduce in massive numbers at once. This flooding overwhelms predators’ capacity to consume and process them, ensuring that a large majority of the offspring survive.

What is a type III predator functional response?

S-shaped curve where consumption rate is low at low prey density, increases at intermediate density and levels off at high density due to satiation

What prevents rapdi prey population at low prey densities in a Type III functional response?

Low predtaor efficiency at low prey density ccaused by prey switching.

What is prey switching

Predators target more abundant preys

What was the key takeaway from Huffaker’s Mite experiments

Adding environmental complexity allowed predator and prey populations to coexist in stable, persistant population cycles rather than going extinct.

How do refuges affect prey vulnerability and population cycles

Prevent complete elimination of prey at low population densities, sustaining predator-prey cycles over time.

How can evolutionary dynamics alter predator-prey cycles?

When predators are abundant, resistant prey genotypes are favored. When predators become rare, non-resistant genotypes with higher reproduction dominate again, increasing prey numbers and subsequently driving predator population growth.

What is the effect of predation?

Negative effect from organism being eaten.

What does predation do?

Lowers N (population size) so it doesn’t reach K (carrying capacity) in prey populations.

Facilitation

Allows population to be above “natural” K

What is the mathematical formula for the probability of being eaten?

P(detection) x P(capture) x P(consumption)

What is an example of capture

A peregrine Falcon can dive at speeds of 200 mph

What is an example of detection

Owls have superb vision and can rotate their heads

What is an example of consumption

A sea star eats a clam with its ability to open the shell and handle its toxins

What can happen to predator-prey cycles

Evolution can alter them