[Leps-l] [leps-talk] Monarch Armageddon

[Foley, Patrick]

While Paul's skepticism may be justified in part, I think he goes too far.

We are not talking about the extinction of a species here, but the disappearance of an adaptive behavior which will no longer be adaptive if the environment changes enough. How much is enough? We don't presently know.

Butterfly migration is hardly universal. Most butterfly species do not migrate with anything like the consistency and vigor of the monarch. It is not obvious that this adaptive migratory behavior can be sustained except under unusual circumstances -- circumstances which we are busy changing.

To end the monarch migration, you do not need to kill off every monarch or every milkweed or every overwintering site. You need to offer monarchs a higher fitness with a different strategy. Since every other butterfly species has a different strategy, such a possibility does not seem remote.

Patrick

Patrick Foley
bees, fleas, flowers, disease
patfoley at csus.edu
________________________________________
From: leps-l-bounces at mailman.yale.edu [leps-l-bounces at mailman.yale.edu] on behalf of Paul Cherubini [monarch at saber.net]
Sent: Tuesday, February 12, 2013 10:50 PM
To: Leps List
Subject: Re: [Leps-l] [leps-talk] Monarch Armageddon

On Feb 12, 2013, at 10:01 PM, Roger Kuhlman wrote:

> Winter roosting locations of Eastern Monarchs are very
> constrained in numbers and locations. These conditions
> put them at a significant risk of extinction.

The eastern monarchs have multiple mountain ranges
in Mexico covered with thousands upon thousands of
acres of forest and the butterflies occupy mere pinpoints
amounts of land within those forests (e.g. 1-5 acres).

So even if those forests were someday heavily logged or
urbanized the butterflies would still be able to find plenty
of cluster trees.

Look at the situation in California:  In very heavily urbanized
areas the monarchs still find overwintering trees on golf
courses and in city parks:
http://www.youtube.com/watch?v=JEhT3Q6b5yE
http://www.youtube.com/watch?v=uwfnWscesIM
http://www.youtube.com/watch?v=kOk2eo3WG_E
http://www.youtube.com/watch?v=pMVQJf6JKOU

One overwinter grove in California that sometimes has
the largest number of monarchs has a busy road
and railroad line running right through it:
http://www.youtube.com/watch?v=vdh8FvFfI0I

> Also I think you know that modern farming practices and
> suburbanization have greatly reduced the numbers of
> milkweeds in both eastern and western US. Fewer
> milkweeds means fewer Monarchs.

But the milkweeds and monarchs still number in the
millions. So how could it be conceivable that the migratory
monarch could go extinct when both the number of
butterflies and the number of it's larval host plants
still number in the millions and will for the forseeable
future?

Paul Cherubini
El Dorado, Calif.
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