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WKCTC Bio121: Modeling Predator and Prey

Todd Levine

A simulation illustrating simple predator prey dynamics. You have two populations, one of which preys on the other.  Each population is affected by a birth and death rate.  The birth rate of the predators depend on their efficiency at harvesting prey items, while the death rate of the prey depends on how many are caught by the predator.

Environment Ecology

  • 7 months 2 weeks ago

Allee Effect from Critical Transitions

Geoff McDonnell

Addition of Allee effect to Logistic Growth Insight 1540. From the Appendix of Marten Scheffer's 2009 Book Critical Transitions in Nature and Society p332 The Allee affect describes a threshold density (smaller than the carrying capacity K) below which populations go into free fall extinction.

Ecology Health Care

  • 6 years 8 months ago

MAT 375 Midterm file: Model of Isle Royale: Predator Prey Interactions

Andrew E Long
This model illustrates predator prey interactions using real-life data of wolf and moose populations on the Isle Royale.

We incorporate logistic growth into the moose dynamics, and we replace the death flow of the moose with a kill rate modeled from the kill rate data found on the Isle Royale website.

Thanks to Jacob Englert for the model if-then-else structure.

I start with these parameters:
Wolf Death Rate = 0.15
Wolf Birth Rate = 0.0187963
Moose Birth Rate = 0.4
Carrying Capacity = 2000
Initial Moose: 563
Initial Wolves: 20

I used RK-4 with step-size 0.1, from 1959 for 60 years.

The moose birth flow is logistic, MBR*M*(1-M/K)
Moose death flow is Kill Rate (in Moose/Year)
Wolf birth flow is WBR*Kill Rate (in Wolves/Year)
Wolf death flow is WDR*W

Environment Ecology Populations Midterm Mat375

  • 1 year 4 months ago