Competition, Predation, Competition, Predation, Symbiosis, Mutualism, Symbiosis, Mutualism,

Commensalism, or ParasitismCommensalism, or Parasitism

Population – group of individuals of the same speciesliving in the same area, potentially interacting

Community – group of populations of different speciesliving in the same area, potentially interacting

What are some ecological interactions?

Why are ecological interactions important?

Interactions can affect distribution and abundance.

Interactions can influence evolution.

Think about how the following interactions can affectdistribution, abundance, and evolution.

Symbiosis – two species live together can includeparasitism, mutualism, and commensalism

CommensalismCommensalism

Commensalism is a relationship between Commensalism is a relationship between two living organisms where one benefits two living organisms where one benefits and the other is neither harmed nor and the other is neither harmed nor helped. helped.

Commensalism – one species receives a benefit fromanother species enhances fitness of one species; noeffect on fitness of the other species

The clownfish lives among the forest The clownfish lives among the forest of tentacles of an anemone and is of tentacles of an anemone and is protected from potential predators.protected from potential predators.

Some birds live among cattle to eat the Some birds live among cattle to eat the insects stirred up as they walk. One insects stirred up as they walk. One

example are egrets who hunt for example are egrets who hunt for insects near a grazing animal's mouth.insects near a grazing animal's mouth.

One animal attaching itself to another One animal attaching itself to another for transportation such as barnacles for transportation such as barnacles

attach to shells or whales or a shrimp attach to shells or whales or a shrimp riding on a sea slugs.riding on a sea slugs.

barnacles on whale’s tail and clam shrimp riding on a sea slug

One species uses a second One species uses a second organism for housing such as small organism for housing such as small mammals or birds that lives in holes mammals or birds that lives in holes in trees or orchids which live in trees.in trees or orchids which live in trees.

Orchid in rainforest Venezuela

ParasitismParasitism

One organism, usually physically smaller of One organism, usually physically smaller of the two (the parasite) benefits and the the two (the parasite) benefits and the other (the host) is harmed other (the host) is harmed

Parasitism – one species feeds on another enhancesfitness of parasite but reduces fitness of host

Ticks and fleas that live in a host Ticks and fleas that live in a host animal's fur bite the animal and animal's fur bite the animal and drink its blood are parasites. drink its blood are parasites.

Insects such as mosquitoes Insects such as mosquitoes feeding on a host are parasites. feeding on a host are parasites.

Vines such as Kudzu growing on TreesVines such as Kudzu growing on Trees

Tomato Hornworm with Wasp Eggs Tomato Hornworm with Wasp Eggs

Tapeworm or Hookworms living in Tapeworm or Hookworms living in Host's Gut Host's Gut

The roots of the Owl Clover are The roots of the Owl Clover are partly parasitic on the roots of other partly parasitic on the roots of other

desert wildflowers. desert wildflowers.

MutualismMutualism

Both species benefit from the interaction.Both species benefit from the interaction.

Mutualism – two species provide resources or servicesto each other enhances fitness of both species

Flowers and their Pollinators Flowers and their Pollinators (examples:  Bees and (examples:  Bees and

hummingbirds gather nectar and hummingbirds gather nectar and spread pollen.) spread pollen.)

Birds and mammals eat berries and Birds and mammals eat berries and fruits while the plant benefits by the fruits while the plant benefits by the

dispersal of it seeds.dispersal of it seeds.

Algae and Fungi > Lichen - Alga Algae and Fungi > Lichen - Alga gets water and nutrients from the gets water and nutrients from the fungus and the fungus gets food fungus and the fungus gets food

from the algae.from the algae.

Cleaners eat insect pests from the skin Cleaners eat insect pests from the skin of animals. (ex: Egyptian plover cleans of animals. (ex: Egyptian plover cleans

giraffes and buffaloes) giraffes and buffaloes)

Many herbivores such as cows, sheep, Many herbivores such as cows, sheep, deer, horses and rabbits depend on deer, horses and rabbits depend on bacteria that live in their stomachs to bacteria that live in their stomachs to

break down the plant material.break down the plant material.

Coral Reefs- The corals get food Coral Reefs- The corals get food and the algae get protection.and the algae get protection.

PredationPredation

one eats another (Herbivores eat plants. one eats another (Herbivores eat plants. Carnivores eats animals.) Carnivores eats animals.)

Competition – two species share a requirement for alimited resource reduces fitness of one or both species

Predation – one species feeds on another enhancesfitness of predator but reduces fitness of prey

herbivory is a form ofpredation

Organizing ecological interactions

effect on species 1

effect onspecies 2

+ 0 -

+

0

-

mutualism

predationherbivoryparasitism

predationherbivoryparasitism

commensalism

commensalism

competition

competition

competition

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