ECOLOGICAL RELATIONSHIPS

ECOLOGICAL RELATIONSHIPS

Population – group of individuals of the same species living in the same area, potentially interacting.

Community – group of populations of different species living in the same area, potentially interacting.

What are some ecological interactions?

Species – group of similar individuals who can interbreed to produce fertile offspring and further generations may also do so.

No organism is an autonomous entity isolated from its surroundings.

An organism's interactions with its environment are fundamental to the survival of that organism and the functioning of the ecosystem as a whole.

Ecological relationships can be classified as predation, competition and as symbiosis.

Ecological Relationships

Predation is when one animal eats another. One species benefits by getting food. The other species is killed.

Predation

Competition is when two organisms are trying to get the same resources: e.g. food, water, sunlight, shelter, mates. Neither species benefits from this relationship, because each organism is taking resources from the other.

Competition

Symbiotic Relationships occur when two organisms live side by side or together.

There are several different kinds of symbiotic relationships:ParasitismNeutralismCommensalismMutualism

Symbiosis

• Mutualism: Both species benefit. The two organisms help each other.

An example would be a honey bee and a daisy. The honey bee gets to eat the pollen from the flower. The daisy uses the bee to spread its pollen to other flowers.

Mutualism

Three Kinds of Mutualisms

1. Energetic & nutritional – transfer of energy/nutrients from one organism to another or to each other

2. Protective – defense against predators or herbivores

3. Transport – movement of seeds, pollen, or adult organisms

Energetic Mutualisms

Gut symbiontbacteria in animal guts digest plant

materials and produce vitamins/amino acidsbenefit to bacteria is a stable environment

and a steady food source

Mycorrhizal fungi fungi that live intermingled with plant rootsfungi uptake nutrients from soil for plantsplants provide carbohydrates to the fungimycorrhizal fungi are found in almost every

plantvery important where nutrients are limited

Mutualism

Lichens are fungi and algae living together. The fungus provides a moist environment for the algae and the algae provides nutrients for the fungus.

Birds and mammals eat berries and fruits while the plant benefits

by the dispersal of it seeds.

Protective Mutualisms

Ants/acacias – acacias provide food, hollow stems for

nestingants attack herbivores and kill encroaching

plantswrens nest in the acacias and are protected

from predators by the ants (commensalism)

Transport Mutualisms

Pollinationflowers trade nectar for pollen transportcan be general or species-specific

Seed dispersal

Plants provide nutritious fruit, seeds to encourage dispersal by animalsmany seeds require gut passage to

germinatesome plants trade-off consumption of some

seeds to ensure dispersal

Seed dispersal

Why does seed dispersal benefit plants? (why not just drop seeds?)

1. Avoid pathogens that the parent may harbor

2. Colonise new habitats where conditions may be better than near the parent

3. Find locations where germination is more likely (ant nests)

Commensalism: One species benefits. The other species is unaffected. A common example is an animal using a plant for shelter.

An American Robin benefits by building its nest in a Red Maple tree. The tree is unaffected.

Commensalism

Commensalism

Barnacles get a free ride by attaching themselves to whales. The whale is unaffected.

Epiphytes are plants that grow on other plants receiving nutrients from the rain, air and any debris that it catches. It does not affect the plant it is fixed on.

Parasitism: Ones species benefits by living in or on the host, or by stealing nutrients from the host. The other species, the host, is harmed.

An example would be a deer tick and a White-tailed Deer. The tick gets food from the deer without killing it. The deer is harmed by losing blood to the tick, and possibly by getting an infected wound.

Parasitism

Parasitism

Mistletoe plants tap into the branches of established plants and steal nutrients from the host plant.

Some fungi digest moist wood, even on living trees.

Neutralism: Neither species benefits or is harmed. Both organisms are unaffected.

An American Goldfinch is a bird that eats mostly seeds. It may share a tree with a Great Crested Flycatcher, which eats mostly insects. Neither affects the other.

Neutralism

Acacia Plant & AntsThe ants lay eggs on acacia tree so they get a nice safe

place for their eggs. The acacia covers the infected area with brown flesh (called a gall.)

The plant has to use valuable resources to create the gall.

What symbiotic relationship is this?

parasitism

Anemone & Clown Fish

mutualism

This fish lives its entire adult life among the tentacles of a bulb-

tentacle sea anemone. Clown fish do not get stung by the anemone as would most other fish so they get

protection from predators. The fish often drop food scraps which the

anemones can eat.

What symbiotic relationship is this?

Boxer Crab & AnemonesThis Boxer Crab carries a pair of stinging anemones in its claws or

on its shell, which it uses to defend itself from predators. The

anemones get to move around which increases their food supply.

mutualism

What symbiotic relationship is this?

The remora attaches itself to the shark and saves energy since it

doesn’t have to swim, and it gets to snack on the sharks kills. The shark

doesn’t get anything.

Shark & Remora

commensalism

What symbiotic relationship is this?

This tiny emperor shrimp is riding along on the back of a sea cucumber (a long worm-like starfish relative) while it crawls along a sandy bottom. The

shrimp gets to travel around under the protection of its much larger partner, and the sea cucumber doesn't seem to

mind.

Emperor Shrimp & Sea Cucumber

commensalism

What symbiotic relationship is this?

Moray Eel & Cleaner Fish

This moray eel has a small fish cleaning between its teeth. The eel gets a clean

mouth while the cleaner fish gets a nice meal.

What symbiotic relationship is this?

mutualism

Cattle & Cattle Egrets

As these cattle walk around eating grass they stir up lots of insects. The egrets hang around and get a

yummy meal of insects.

What symbiotic relationship is this?

commensalism

Antelope & Ox Bird

This ox bird hangs out on the antelope and

gets a delicious meal of bugs living on the

antelope. The antelope gets rid of parasites.

What symbiotic relationship is this?

mutualism

Loa Loa Worm & Human

This worm infects humans via the blood stream and

gets a nice warm safe home there. The

human may go blind or have other complications

as a result.

What symbiotic relationship is this?

parasitism

Goby and Alpheid Shrimp

What symbiotic relationship is this?

mutualism

This alpheid shrimp (onthe right) uses its strong claws like a bulldozer to create a burrow in the

sand. The shrimp is nearly blind. It relies upon its partner, the sharp-eyed goby, to warn of danger.

When a potential predator approaches, both animals disappear quickly into the

burrow

Wrasse & BatfishCan you see the two cleaner wrasses are

removing parasites from a batfish? One of the

wrasses has entered the gill slit of the batfish, and

may even enter itsmouth in search of food.

The batfish gets a bath and the wrasse gets a meal.

What symbiotic relationship is this? mutualism

Hummingbird Moth & Flower

This hummingbird moth is drinking the nectar of a flower. The flower gets pollinated (the moth brings pollen from other flowers) and the moth gets a

tasty meal.

What symbiotic relationship is this?

mutualism

Organising ecological interactions

effect on species 1

effect onspecies 2

+ 0 -

+

0

-

mutualism

predationparasitism

predationparasitism

commensalism

commensalism

competition

neutralism