Mike wrote:
Oh, and just one other point. Does this mathematical model take
population viability levels into account? Or does it just show the
time to extinction?

I saw a model here which demonstrates that population viability levels
reach a critical point quite a while before actual extinction, but
this also accelerates the extinction. ( Hope that made sense?).

Unfortunately I don´t know what this model is called.

The Ricker model is mostly used to predict a time series of data, i.e.,
numbers at one time as a function of numbers at an earlier time. It
differs from the logistic model in that negative population growth can
occur at high numbers; it becomes quite a bit more stochastic, and even
chaotic.

The authors mainly used the Ricker model to estimate population rates of
change, then used a viability analysis to estimate extinction times.

Tim Lysyk