Isle Royale Ready

Bonus QUIZ!!!!!!

Isle RoyaleWolves vs Moose

Objectives

These objectives will be accomplished via a computer simulation of Isle Royale:

• Understand various population ecology terms

– Exponential growth, logistic growth, carrying capacity, and limiting

factors

• Take a real life uninhabited ecological system and learn about

various aspects of population ecology

• Observe how variation in climate effects

– Population size and predator-prey relationships

Isle Royale Location

Isle Royale Background

• In 1900 pioneer moose swam across the open ocean to the uninhabited island

• The moose entered paradise– No predators and full of grass, shrubs, and trees to

eat

• Moose population explosion (30 yrs.)– Several thousands at its peak

• Something disrupted their paradise!!!!!!

Wolves Introduction• Lake Superior frozen in 1940 allowing an ice

bridge to form

• Small pack of wolves found the bridge and crossed to the island

• Wolves paradise began– Huge population of weak moose because of lack

of food

Natural Experiment

• Moose and Wolves have been studied since 1958– Longest running experiment of its kind

• Isolation of the island provides good condition to study predator-prey system– Large enough to support wolf pop, small enough

to keep track of wolves and moose pop annually

Important Population Ecology Terms

• Population ecology is the study of changes in size and composition of a population and the factors that cause it

• Two types of Population Growth Models:– Exponential and Logistical– Useful in helping to understand complexity of pop

growth and predict how pops will change through time

Exponential Growth Model

• No limitations to pop growth– All resources for survival

and reproduction are present

• Larger pop=faster growth– Each successive

generation produce more individuals which cause more and more offspring

dNdt

=rmax N

•rmax represents maximum per capita rate of growth=intrinsic rate of increase

•N=pop size

•t=time

Logistic Growth Model

• Real world model– Limited by availability of

important resources

• Carrying capacity (K)– The max # of species that the

local environment can support at any particular time

– Starts off exponential when the pop is small

– Begins to level off when the resources start to get used up and pop gets large

dNdt

=rmax N (K-N)K

r= per capita growth rateas density

N=K when carrying capacity is reached

Computer Simulation

Part A. The Moose Arrive

Part B. The Wolves Arrive

Part C. Changes in the Weather

Wrap up

• Discuss Presentation with Group Members• Next week:– Quiz 5• Invasive Species and Biological Control (Lab 6) and Isle

Royale(Lab 8)

– PRESENTATIONS!!!!!• Come prepared!!!