HOW ORGANISMS INTERACT IN COMMUNITIES WHAT SHAPES A

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HOW ORGANISMS INTERACT IN COMMUNITIES WHAT SHAPES A COMMUNITY? ? PREDATION & COMPETITION!! (food,

HOW ORGANISMS INTERACT IN COMMUNITIES WHAT SHAPES A COMMUNITY? ? PREDATION & COMPETITION!! (food, SHELTER, light, nutrients, water)

Five Basic Interactions Between Species 1) Competition 1) Interspecific competition – between two or

Five Basic Interactions Between Species 1) Competition 1) Interspecific competition – between two or more species 2) Intraspecific competition – between members of same species 2) Predation 3) Parasitism 4) Mutualism 5) Commensalism

WHAT IS A NICHE? An organism’s niche describes: 1. The organism’s role in the

WHAT IS A NICHE? An organism’s niche describes: 1. The organism’s role in the community 2. It’s use of resources

§Fundamental Niche §the full range of conditions and resources it could potentially use §Determined

§Fundamental Niche §the full range of conditions and resources it could potentially use §Determined by abiotic factors §Realized Niche §that part of a fundamental niche that an organism occupies §Determined by biotic factors (COMPETITION!)

INTERSPECIFIC COMPETITION = niches of two different species overlaps §Migrate §Shifts its feeding habits

INTERSPECIFIC COMPETITION = niches of two different species overlaps §Migrate §Shifts its feeding habits §One of the species suffers population decline (even to extinction)

If the niches of two species overlap completely or significantly – how long can

If the niches of two species overlap completely or significantly – how long can they both last? What’s an organism to do? Move, adapt, or die Avoid or weaken competition by: Symbiosis Resource partitioning

A niche restricted by competition is a a) Fundamental niche b) Realized niche c)

A niche restricted by competition is a a) Fundamental niche b) Realized niche c) Resource partitioned niche True or False: A fundamental niche includes the full resources and habitat an organism can survive in.

§ Have broad ranges § Live in a variety of places, eat a spectrum

§ Have broad ranges § Live in a variety of places, eat a spectrum of foods, & tolerate a wide range of environmental conditions § Have narrow ranges § Live in one type of habitat, rely on one type of food source, or have limited range of environmental tolerance § Are typically endangered species

A: Interspecific Competition B: Intraspecific Competition 1. Two squirrels race up a tree to

A: Interspecific Competition B: Intraspecific Competition 1. Two squirrels race up a tree to reach a hidden pile of nuts. 2. A hyena chases off a vulture to feast on an antelope carcass. 3. Different species of shrubs and grasses on the forest floor compete for sunlight. 4. Brown bears hunting for fish on a river’s edge fight over space. 5. Male big horn sheep butt heads violently in competition for mates.