Spotted owls and flying squirrels:
using eigen-analysis to predict observed behavior of a discrete linear dynamical system

Peter Brown
Center for Computer-Based Instructional Technology,
Department of Computer Science

Murray Eisenberg
Department of Mathematics and Statistics

University of Massachusetts, Amherst

Note to reviewers:  In this alpha version, some references and other items are missing.  And we need to check the units for these populations, i.e., measuring in tens, hundreds, thousands?  also what the time units are, i.e., months, years.


Northern spotted owls and flying squirrels inhabit old-growth forests in the northwestern United States.  The squirrels are a major food source for the owls: the owls just love to eat squirrels.  Collected data (see [source to be supplied]) provides month-by-month population figures for both owls and squirrels.  The main problem here is to explain certain numerical regularities one can observe in such data and, more importantly, to be able to predict these regularities if one knows just the two population sizes at any one given starting time.



•The model




•Questions: growth rates


•Questions: relative population sizes


•Using eigenvalues [hardly begun!]



 Converted by Mathematica  (September 5, 2002)