b-fly releases at events

[Paul Cherubini]

Patrick Foley wrote:

> There is considerable scientific value in knowing about stray butterflies.
> As Ehrlich's group and Ilkka Hanski's group and others have shown, butterfly
> populations are not always persistent locally. Metapopulations (in the broad
> sense) persist only if recolonization occurs, but such recolonization events
> are tricky to study quantitatively. They are often rare events. If natural
> recolonizations are swamped by schoolchild releases, we have little hope of
> evaluating the viability of metapopulations. 

If we replace the word "butterfly" in your piece above with "Painted
Lady" (the species under discussion) this is what we end up with:

"There is considerable scientific value in knowing about stray Painted
Ladies.
As Ehrlich's group and Ilkka Hanski's group and others have shown,
Painted Lady populations are not always persistent locally.
Metapopulations of Painted Ladies (in the broad sense) persist only if
recolonization occurs, but such recolonization events are tricky to
study quantitatively. They are often rare events. If natural
recolonizations of Painted Ladies are swamped by schoolchild releases,
we have little hope of evaluating the viability of metapopulations of
Painted Ladies."

Pat, could you present us with a mathematical model of risk that would
help everyone understand how there is a reealistic chance that natural
recolonizations of Painted Ladies could be swamped by school releases
and thus destroy our ability to evaluate the viability of
metapopulations of Painted Ladies? 

Paul Cherubini, Placerville, California