Graphical Estimation of the ``Critical Value'' of the Juvenile Survival Rate

The ``critical value'' of the juvenile survival rate is the value of t that corresponds to a transition matrix whose dominant eigenvalue is at least 1.

> for t from 0.18 to 0.30 by 0.01 do

> A[2,1] := t;

> map( abs, [eigenvalues( A )] );

> od;

Thus, somewhere between t=0.25 and 0.26 the dominant eigenvalue goes from being less than 1 to greater than 1. This means that any owl population that initially contains a nonzero component in the eigenspace of the dominant eigenvalue will survive forever.

>