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  • While we welcome the sight of our first monarch this spring, Dr. Lincoln Brower reports concern about this year's early migration, and its implications for conservation:

    "Monarch Watch messages coming in from numerous observers east of the Rocky Mountains indicate that the monarchs are moving northward on their spring remigration back into the USA much earlier this year (1997) than is normal. I believe that this is ominous for the following reasons:

    "Several observations made this spring (February-March 1997) in Mexico suggest that monarchs began leaving the Rosario and Sierra Chincua overwintering sites at least 2 to 3 weeks earlier than usual. I think the main reason for this (and this trend seems to have begun at least 2 years ago) is that illegal thinning of the forest inside the colony boundaries and denuding the forest adjacent to the colonies is allowing the dry season winds to penetrate through the forest with a higher velocity. This then leads to higher evaporation rates of critical moisture stored by the butterflies. In other words, the monarchs may well be leaving Mexico early because deforestation is speeding up the otherwise normal rate at which the butterflies dessicate. What I think we are witnessing is the unraveling of the microclimate in Mexico due to the relentless thinning of the Oyamel forests which is stimulating the butterflies to leave sooner. Keep up the good reporting. The data are invaluable.

    Lincoln P. Brower
    Professor of Zoology
    University of Florida

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