Ch. 14 - Exploitative Interactions

Exploitative Interactions

Interactions in which one organism increases its fitness at the expense of another organism.

What are the different kinds of exploitation?

Herbivory, parasitism, predation, pathogens

What kind of exploitation are caddisfly larvae (studied by Lamberti & Resh (1983))?

Herbivory (they eat algae and bacteria)

What kind of exploitation is the influence of birds/bats on tropical forest arthropods?

Predation

What kind of exploitation is the chytrid fungus that has affected the amphibian populations?

Pathogens

What 3 trophic levels contribute to the snowshoe hare & predator population cycles?

• the hares

• food supply (quantity/quality)

• predators

What are some complex exploitative interactions?

• parasites altering behavior in birds (ex. spiny headed worms)

• Rust fungus manipulating the growth of host mustard plants

• Cordyceps (fungus) that attack and infect ants.

Refuge

Protection of exploited populations from predators and parasites.

Types of refuge

• physical refuge - e.g. large size, camouflaging

• numbers/grouping

• flight

• spatial - burrows, trees, env.