Effects of migration on populations

Paul Cherubini monarch at saber.net
Sun Dec 9 16:56:55 EST 2001

Pat wrote:

> I doubt that many butterfly releasers take the potential 
> effects on their species seriously or they would be
> supporting research on the problem.

Butterfly breeders have supported relevant research on monarchs
when scientifically legitimate concerns were raised about the potential
environmental impact of shipping these butterflies around the 
USA and Canada for release. Example, the tagging study in the
Rocky Mts. I talked about in my last post cost $10,000.

But instead of scientifically valid concerns from the academic and
regulatory community supported by mathematical models showing 
the potential impacts, we usually get "off-the-wall speculation" 
(as Norbert Klonda put it) like this: 

"Wayne Wehling, a USDA specialist in plant-feeding insects, said 
at least some milkweed species in Oklahoma and in Arizona are 
endangered. Allowing unregulated interstate shipment and release of 
the butterfly, Wehling said,  could tip the balance against the plants, 
on which the migrating Monarch habitually lays its eggs."

Worse, instead of challenging the scientific legitimacy of speculation
like this we see some monarch scientists enthusiastically urging new
research to address these questionable concerns -  research that would 
take hundreds of thousands of dollars and years to complete  Examples: 
Dr. O.R. (Chip Taylor) wrote a few days ago wrote on dplex-1:

"It is up to us to urge that appropriate research be done,
should evidence be lacking, on a particular issue - such as
whether monarchs are even known to utilize the threatened
milkweeds as hostplants in OK and AZ. Are monarchs common or rare 
during the time when these plants are pre-senescent (i.e. potentially
suitable hosts)? Does herbivory by monarch larvae, if it occurs, actually
constitute a threat to long lived (100 years) perennial milkweeds? "

Most dismaying of all,  Dr. Karen Oberhauser advocates not only
questionable new research, but a zero risk impact standard. On dplex-l
a few days ago Karen wrote: 

a) it seems to me that it makes most sense to put the burden of 
proof on the other side, and say that we should not move them long 
distances until it's been shown that it won't have negative impacts.

b) If releasing monarchs near endangered plants has even the 
slightest chance of hurting those plants, we shouldn't do it

c) If shipping monarchs from Minnesota to Maine has even the 
slightest chance of disrupting genetic structure, or of making it difficult 
to study that structure, I don't think we should do it.

Paul Cherubini


   For subscription and related information about LEPS-L visit:


More information about the Leps-l mailing list