Keystone Species Questions and Answers

1. Make a list of the organisms in the article dealing with wolves. Wolves -jays -deer Grizzley -magpies -rodents Wolverines -martins -insects Bald Eagles -black bear -fungi Gold Eagles -coyotes -bacteria Ravens -foxes -elk Mt. Lions -hares -beaver Otter -moose -ducks Mink -wading birds -songbirds Fish -frogs -grass Willow -Aspen -cottonwood

2. Make a list of some species interactions. Predator-Prey: wolves and elk, coyotes and mice Interspecific comp: wolves and mt lions, moose and beaver Intraspecific comp: mice with mice, wolves with wolves Mutualism: beaver and willow Commensalism: magpies and wolves

3. Food Web from list

4. What is a Trophic Cascade?

A Trophic cascade is when a predator has an indirect effect (either increase or reduction) on a non-prey item at a lower trophic level. Example: the predator (bird) has a positive effect on the basal species (plant) via reduction in the abundance of the herbivore (caterpillar).

5. How is the starfish a keystone species?

6. Are keystone species always predators?

They help to maintain suitable habitats for many other species in savanna and forest ecosystems. directly influence forest composition and density In tropical forests, elephants create clearings and gaps in the canopy that encourage tree regeneration. In the savannas, they can reduce bush cover to create an environment favorable to a mix of browsing and grazing animals. Many plant species also have evolved seeds that are dependent on passing through an elephant's digestive tract before they can germinate; it is calculated that at least a third of tree species in west African forests rely on elephants in this way for distribution of their future generations.