Species InteractionsSpecies Interactions

By Mr. “I got worms” ChapmanBy Mr. “I got worms” Chapman

Concept to UnderstandConcept to Understand

• Species interactions affect the resource use and population sizes of the species in an ecosystem.

Species InteractionsSpecies Interactions

• Symbiosis – interactions between species.• Ex. Predation, parasitism, competition,

mutualism, and commensalism.

Interspecific CompetitionInterspecific Competition• 1. Competition – the most common interaction

between species• No two species can share vital limited resources

for long (no same niche).

Interspecific CompetitionInterspecific Competition• Resolved by:

– Migration – move somewhere else– Shift in feeding habits or behavior – eat something else– Population drop – fewer individuals– Extinction – die out

Intense competition leads to Intense competition leads to resource partitioning – resource partitioning – each species becomes more specialized each species becomes more specialized

Cape May Warbler

Blakburnian Warbler

Black-throated Green Warbler

Yellow-rumped Warbler

Bay-breasted Warbler

Fig. 5-2, p. 81

InteractionsInteractions• Competition – when 2 or more species

use the same limited resources.– Competitive Exclusion

PredationPredation

• Predation – one individual, the predator, captures, kills, and consumes another individual, the prey.

PredationPredation

• Predation influences where and how species live and is an effective way to regulate population size.

Predator TechniquesPredator Techniques

• 1. Ambush (lions)

• 2. Camouflage (praying mantis)

• 3. Chemical warfare (poisonous snakes)

Prey TechniquesPrey Techniques• 1. Evasion (birds – fly away)

• 2. Alertness – highly developed senses (fly – compound eye)

Prey TechniquePrey Technique

• Mimicry – a type of defense where harmless species resemble a poisonous species.

Prey TechniquesPrey Techniques• Protection – shells, bark, spines, thorns (turtle,

porcupines)

• Camouflage (leaf insects)

Prey TechniquesPrey Techniques• Warning coloration (poisonous dart frogs,

taste bad)

• Behavioral strategies – puffing up (blowfish)

CoevolutionCoevolution• Predator and prey Relationship• Intense natural selection pressure on each other• Each can evolve to counter the advantageous traits

the other has developed called Coevolution.– Bats and moths

ParasitismParasitism• Parasitism – one individual, known as

parasite, feeds on another individual, known as the host.

• Parasites promote biodiversity – help keep populations of hosts in check

InteractionsInteractions• Mutualism – is a cooperative relationship

where both species benefit.

– Ex. Clown fish and anemone

MutualismMutualism• Both species benefit

– provides food, shelter, or some other resource

• Nutrition and protection

• Gut inhabitant mutualism

InteractionsInteractions• Commensalism – is interaction where

one species benefits and the other is not affected.

– Movement of buffalo and birds eat insects and lizards

CommensalismCommensalism• Benefits one species with little impact on

other

Animation: How Species Animation: How Species InteractInteract

PLAYANIMATION