Types of Relationships in
Ecosystems
Notes page 73
Predator/Prey
• An organism KILLS and EATS all or part of
another organism.
Competition
• Organisms compete for resources or same
goal that two cannot attain
– Ex.) Plants in the Rainforest competing for
light
– Two birds competing for a mate
Symbiosis
Close, long-term relationship(s)
between different species within
an eco-system.
3 Major types- Mutualism,
Commensalism, and Parasitism
Mutualism
• This is a winwin relationship
• Both
organisms
benefit from
each other
• 
Commensalism
• This is a win-??
(no one cares)
relationship
• One organism
benefits, the other
one doesn’t care –
it isn’t helped or
harmed.
• 
Parasitism
• This is a win-lose
relationship
• One organism
benefits, the other
is harmed
• 
tick
flea
Digger Bee & Palo Verde
•Mutualism
Gila Woodpecker & Screech Owl
• Commensalism
•
http://helios.bto.ed.ac.uk/bto/desbiome/saguaro.ht
m
Mexican Long-tongued
Bat & Palmer Agave
• Mutualism
Phainopepla & Mistletoe
• Mutualism
•
•
http://waynesword.palomar.edu/plnov99.htm
http://www.laspilitas.com/California_birds/Silky_flyc
atcher/Phainopepla..html
Cowbird & the Oriole
• Parasitism
Wood Rat & Prickly Pear
• Mutualism
•
•
http://www.arizonahighways.com/custom.cfm?name
=c_nature.cfm&secid=33&id=144
http://www.desertusa.com/magoct97/oct_pa/du_prk
pear.html
Cactus Wren &
Cholla Cactus
• Commensalism
•
http://www.arizonahighways.com/custom.cfm?name=c_nature.
cfm&secid=37&id=100
Hummingbird & Ocotillo
• Mutualism
•
http://www.desertmuseum.org/pollination/hu
mmingbirds.php
Saguaro & Palo Verde
• Commensalism
•
http://lowenddslr.com/photos/sabino-canyon-nursery-tree.php
Desert Tortoise / Prickly Pear
• Mutualism
Mistletoe and Mesquite
• Parasitism
Mistletoe is a
parasite. It
lives off of
another
plant. (They
like Mesquite
trees)
•
http://helios.bto.ed.ac.uk/bto/desbiome/parasite.htm
Javelina and Mesquite
• Mutualism
Gila Woodpecker & Saguaro
• Commensalism
Broomrape & Bursage
• Parasitism
Yucca & Yucca Moth
• Mutualism
•
http://waynesword.palomar.edu/ww0902a.htm