Shocking Monarch News – California Coast 2020

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    Caryl
    Participant

    On January 17, 2021, the Xerces Society – an international conservation group – announced the results of its 24th annual winter butterfly count, and the news isn’t good for butterfly lovers. The group reported that the population of monarchs that winters along the California coast hit a low of less than 2,000 butterflies, a 99.9% decline since the 1980s, when up to 10 million butterflies overwintered in California. Read more here and glorious photos.

    Monarch butterflies are in trouble: Here’s how to help in your own yard

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    Jacqui
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    I have been monitoring this discussion. Andy Davis (a research scientist at the Odum School of Ecology, University of Georgia and editor of the journal ANIMAL MIGRATION) says:

    “From everything we know right now, once a population becomes a permanent-resident one, then that’s it, there is no turning back to a migrant one. Of all of the resident populations around the world, none have shown any indication of switching to a migratory one, and in fact, it has been the opposite in most cases (migrants that become resident).

    “This issue has in fact been studied very well in fact. Two years ago, a study was spearheaded by Micah Freedman, who asked if resident monarchs have the ability to switch back to migrants. The answer was maybe. However, the issue, as John pointed out, is that once they become permanent residents, their OE level goes up and you don’t really want them to become migratory at that point (even if they could migrate with OE, which is doubtful).

    “For grins, I went back and looked at the blog I wrote at the time for this study, and ironically, all of these same issues were raised 2 years ago – OE, resident switching, “refuge” populations, tropical milkweed…

    Can non-migratory monarchs still become migratory – answer: maybe, but…

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