Functional Response to Predators

A species interactions where one species feeds on another which enhances the fitness of the predator but reduces the fitness of the prey

Predation

An organism that is killed and eaten by other animals

Prey

An animal that kills and eats other organisms

Predator

Prey-predator system between Paramecium and Didinium in oat medium without sediment

Cyclical Oscillations

Interaction between two animals where one will be eaten by the other

Carnivorous predation

The consumption of plant material by animals, and herbivores are animals adapted to eat plants (browsers and grazers)

Herbivory

An individual organism, the parasite, consumes nutrients from another organism, its host, resulting in a decrease in fitness to the host

Parasitism

Predators eyes face forwards to give them a clear view of their prey

Eye position

Have sharp claws that the predators use to hold onto prey while they are killing it

Feet

sharp, pointed teeth for grabbing and cutting their food. Predators don’t usually chew the meat completely. It is swallowed whole or in chunks

Teeth

Characteristics of predators

• eye position

• Feet

• Teeth

Characteristics of prey

• eyes

• Feet

Located on the side of the head so they can see if predators are approaching

Eyes

Made for running

Feet

Predation influences the?

Predation influences the fitness of both predators and prey. individuals must both feed and avoid being eaten to survive and reproduce

How has predation influenced evolution

Coevolution

The influence of closely associated species on each other in their evolution

Coevolution

• also known as cryptic coloration

• A defense mechanism or tactic that organisms use to disguise their appearance, usually to blend in with their surroundings

Camouflage

• the act or art of copying or imitating other organisms

Mimicry

• batesian mimicry

• Mullerian mimicry

• the use of warning coloration to inform potential predators that an animal is poisonous, venomous or otherwise dangerous

Aposematic coloration

Two categories of plant defense against herbivory

• tolerance

• Resistance

Constitutive or induced defenses

Resistance

What are examples of physical defenses

Thorns on roses, spines on a cactus

This are secondary metabolites

Chemical defenses

• carbon-based defenses and nitrogen-based defenses

• Some plants can attract natural enemies to herbivores-indirect defense (e.g ants reduce herbivory)

Changing the number of prey can cause 2 types of responses which are?

1. Functional response

2. Numerical response

• describes the change in the number of prey consumed by an individual predator as prey density changes

• Rate of consumption vs. prey density

• Predation rate change with increasing prey abundance

Functional response

• describes the change in predator population density as prey density changes Rate

• Increase in prey density leads to increase in predator population density

Numeric response

• prey are consumed in direct proportion to their availability

• Known as Type I functional response

• Predators never satiate

• No limit on the growth rate of predators

Lotka-Volterra

Consumption rate increases at first, but eventually predators satiate (upper limit on consumption rate)

Type II functional response

Consumption rate is low at low prey densities, increases, and then reaches an upper limit

Type III functional response