predation, herbivory, and parasitism without functional response

types of species interactions

• competition (-/-)

• amensalism (0/-)

• exploitation (-/+)

• neutral (0/0)

• commensalism (0/+)

• mutualism (+/+)

passive transmission

mode of parasite transmission where the parasite or host does not respond to each other

active transmission

a mode of parasite transmission where the parasite or host responds to each other

hyperparasite

parasite on a parasite

are parasites considered predators?

no, they typically don’t kill the host, that is their home

parasitoids

function like parasites, but they purposefully kill their prey (so they are technically predators)

types of herbivory

• grazers

• browsers

• granivores

• frugivores

granivores

eat seeds (are the only herbivores considered “predators” because they eat seeds)

microbial symbionts

herbivory only exists because of these symbionts (help break down the cellulose in animals) (is a form of mutualism)

types of plant defenses

• chemical

• mechanical

• nutritional

• tolerance

chemical defense in plants

producing chemicals that are noxious or poisonous to herbivores

mechanical defense in plants

developing structures like thorns that make it harder for animals to eat them

nutritional defense in plants

growing structures that are less nutritious for grazers (have less N and P) (excess of C)

tolerance defense in plants

adaptations to regrow quickly after being grazed

predator hunting tactics

• pursuit

• stalking

• ambush

• random chance

prey defenses

• cryptic coloration

• object resemblance

• flashing coloration

  • tend to combine with camoflage

• chemical

  • when in use, they advertise it

• aposematic coloration

  • warning

• batesian mimicry

  • not toxic mimics something that is

• mullerian mimicry

  • those who are toxic will use the same coloration to amplify the message

• protective armor

predator satiation

overwhelm with numbers to reduce an individuals risk

lotka-volterra equations: searching efficienty (attack rate)

α

lotka-volterra equations: encounter rate

Nprey-Npred

lotka-volterra equaions: prey consumption rate

α(Npre-Npred)

density-dependent relationships

prey and predator isocline

prey isocline

number of predators at which the prey population does not change

predator isocline

number of prey at which the predator population does not grow

deterministic

always know how the cycle will happen

stochastic

accounts for randomness

type 1 functional response

minimal handling time (not common)

• predation rate increase linearly with increasing prey density

type 2 functional response

handling time vs search time

• handling

• chasing

• killing

• ingesting

• digesting

predation rate increases with prey density, but the rate of increase slows down as prey density gets higher & the predation rate eventually levels off

type 3 functional response

• prey refuges

• increasing difficulty of encountering prey as they became scarce

• choice among multiple prey species

• coevolutionary changes

• search image

• switching

  • so few prey, they just give up (could be seasonal)

shows an S-shaped curve, with predation rate increasing more slowly at low prey density, then more quickly at higher prey density

• like a type 2 response, it gradually levels off at a maximum predation rate

coevolution

occurs when two species that live in a close association both adapt in response to selective pressure from the other