Warm Up: Image Explain: In your notebooks, find 3-4 errors with this food web, and describe how to fix them.

During which years is the population of willow trees growing exponentially? 2. What is the carrying capacity of this population? 3. What kind of graph is shown when a population reaches its carrying capacity? Warm Up #2 4. Explain why a population cannot grow exponentially forever.

Communities – All the living things in an ecosystem Community Interactions Chapter 4.2 – Page 92 Communities – All the living things in an ecosystem

Predator-Prey Interactions

Predation Definition: An interaction in which one organism captures and eats another PREDATOR – the organism doing the eating PREY – the organism getting eaten

Predation: Not Predation:

“Boom – Bust” Population Cycle Some populations increase rapidly and then decrease rapidly THINK ABOUT IT…. Describe why a predator – prey interaction usually results in a boom-bust cycle (BOOM) (BUST)

Predator ADAPTATIONS: Things that help them find and capture prey easier Speed / Agility Coloring Team up in packs Acute senses Claws, teeth, fangs, stingers

Things that help them avoid getting eaten Prey ADAPTATIONS Things that help them avoid getting eaten Retreat to safety Flee quickly Camouflage Warning coloration Mimicry

A closer look at MIMICRY

Competition When two or more organisms attempt to use the same ecological resource in the same place at the same time Can occur between members of the same species, or between members of different species Organisms compete for food, water, space, sunlight… other essentials

Symbiotic Relationships Definition: A close interaction between two species in which one of the species lives in or on the other.

One organism benefits, the other is harmed Parasitism One organism benefits, the other is harmed Examples: Tapeworm Mosquito Fleas/ticks Sea Lamprey Bacteria

Both organisms benefit from the interaction Mutualism Both organisms benefit from the interaction Examples: Bee and flower Crocodile and Plover Oxpecker and Zebra

One organism benefits, the other is neither helped nor harmed Commensalism One organism benefits, the other is neither helped nor harmed Examples: Fringed toed lizard and rat Moss and tree Barnacle and whale

Symbiosis Image Explain What kind of relationship is this? (MUTUALISM, COMMENSALISM OR PARASITISM?) Who benefits? How can you tell?

Symbiotic – Crab Example Read the article and determine what type of relationship is shown. How can you tell? BRAIN POP!!!