opinion re butterflies raised in captivity in USA

This topic contains 5 replies, has 5 voices, and was last updated by  monkey 2 months, 1 week ago.

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  • #57204

    monkey
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    AYE TENGER-TROLANDER
    Monarch butterflies raised in captivity don’t migrate
    By Elizabeth PennisiJun. 24, 2019 , 3:20 PM
    In what may be a cautionary tale for citizen scientists trying to save North America’s iconic monarch butterfly, new research has found that butterflies raised in captivity are sometimes unable to migrate—some as a result of missing genes and others for want of the right environmental cues.
    A graduate student discovered this genetic shortfall after buying dozens of monarchs and tethering them to a short pole—a common method to test what direction an insect wants to fly. Tethered wild-caught monarchs consistently headed south, the same direction they fly during their annual journeys from the United States and Canada to Mexico. But neither commercially sourced monarchs nor local individuals raised indoors did. They tended to head in random directions.
    To see why the monarchs weren’t trying to fly south, the researchers sequenced the DNA of some of the butterflies and compared it with the already-sequenced monarch genomes. They found many differences but did not pin down any particular gene. But even with the right genes, the local butterflies raised indoors couldn’t head in the right direction; the researchers think that because outdoor-raised butterflies orient south, but ones raised indoors don’t, the latter are not getting the environmental cues that would signal them to fly south, they report today in the Proceedings of the National Academy of Sciences.
    Over their long evolutionary history, monarchs that have spread to Africa, Australia, South and Central America, and Hawaii have ceased to migrate; with mild local conditions, they have no need to go anywhere else. But butterflies in colder climates such as North America don’t survive the winter if they don’t migrate.
    Thus, the researchers say, the recent request for the U.S. government to list the species as threatened may be warranted. The findings also suggest school groups and hobbyists who raise monarchs to bolster the species’s population may want to source them locally and raise them outdoors for their entire life cycle.

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  • #57236

    monkey
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    I read with interest the article on Monarchs, & I suspect that it is correct, in North America where the weather conditions are so much harsher up North than they are here. My understanding is that the butterflies there progressively move south with each generation, finally the last generation of each season ending up in Mexico
    Here of course, NZ has a much more temperate climate & migration is not a necessity, with Monarch butterflies just clustering in certain places over winter. I understand that they leave pheromones in the selected overwintering trees & that is why each year they cluster in the same area. There are places in NZ which are well-known for over-wintering – Butterfly Bay somewhere in Northland & also I think, Hagley Park in Christchurch. So that explains why I’m so excited to see them in our area in Hamilton

    #57230

    Terry
    Participant

    Take that research with a pinch of salt! It would need to be repeated many times in different areas and settings to be proved good science. Next step, indoor raised Monarchs tagged and released and monitored. Could be they take a period of time to orientate themselves before they too would head South. Therefore incomplete data has been gathered at this stage. Not all vanessa cardui from UK bred summer generations head south back toward North Africa but some do make a return flight (why only some?) as do Vanessa atalanta, however Vanessa atalanta has the advantage of a few surviving overwintering here if the cold that winter is not too extreme.

    #57228

    Jacqui
    Moderator

    Remember that this article has been written by Americans for a North American audience. It’s different here in NZ. The monarchs are not seen as a “native” (although they are classified as a native as they flew/blew here) but not seen as a species that needs protecting.

    I don’t think anyone in NZ raises captive monarchs – most (everyone?) takes eggs from wild monarchs and I won’t say raises them in captivity but rather protects them from predators, re-releasing the adults.

    #57219

    LeslieD
    Participant

    Given the DNA differences I’d be curious to know how many generations have been raised indoors? I expect most of our ‘indoor’ butterflys are bought in from the wild population at some stage (eggs or caterpillar). And ‘indoor’ varies from shadehouse, caterpillar castle, through to actually being indoors or a greenhouse. Its hard for me to see how part of a lifestage of one caterpillar bought in from the wild, spent in some sort of shelter on usually natural vegetation would be sufficient to alter the DNA and/or stuff up its natural survival senses. But it would be interesting to hear the views of the scientist people like Terry or Norm.

    Slightly off topic but concerning gene pool, I think there is value in taking in caterpillars from another area which happens a lot here.

    #57218

    FiLeBeau
    Participant

    How very interesting. We raise around 2000 Monarchs here each season. Half are outside in the large shadehouses and half are indoors. All are released outside once their wings are dry. We have noticed that most of them fly North immediately, or fly in a few circles then fly North. Very few stay around the garden.

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