Predator & Prey Competition Relationships 11/3/2014

Predator Prey Relationships As the predator obtains food, the prey has a negative interaction (death) However, the overall prey population is improved. Weak Sick Injured Keeps in check with available resources

Deer Population DATA 6th: 8 12 6 10 “Oh, Deer!” Game Deer Food Water Shelter Deer Population DATA 6th: 8 12 6 10 20 Deer Population 10 Trials

Deer Population DATA: 2nd Period 11 18 6 12 17 8 16 10 19 “Oh, Deer!” Game Deer Food Water Shelter Deer Population DATA: 2nd Period 11 18 6 12 17 8 16 10 19 20 Deer Population 10 Trials

Deer Population DATA: 4th Period 12 20 8 18 16 14 “Oh, Deer!” Game Deer Food Water Shelter Deer Population DATA: 4th Period 12 20 8 18 16 14 20 Deer Population 10 Trials

Predator/Prey Relationship When a predator species is removed from the ecosystem, the prey population dramatically increase in numbers and often starves through lean seasons. Removing WOLVES from the forest Explosion of deer population Deer starved over winter due to lack of food to feed the increased population.

Predator and Prey Populations

Competition – driving force behind natural selection Populations compete for limited resources: Water Energy Living space Mates Competition within a species may result in the better-adapted individual, eliminating the less fit competitor. “Survival of the Fittest”

Interspecific (between species) competition Negatively effects both competing population Resources are finite If only one species, the number of individuals in the population would be greater than if the limiting resources were divided between two species. EXAMPLE: Lions and Cheetahs Extinction of species: one out competed by another using available resources the population could decrease until no individuals remain.

Competition: Paramecium and P. aurelia Survival of the Fittest Natural Selection