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    Re: Monarch Butterfly Navigation
    From: Frank Reed
    Date: 2016 Apr 19, 17:00 -0700

    Francis Upchurch, you wrote:
    "Down here in SW Cornwall, there are multiple confirmed stories of some of the old fishing boat skippers, back in 50s-early 60s, before Decca, loran, GPS, who regularly went out after a storm to find lost net gear, steamed 50 miles out with no charts or keeping dead reckoning, just a compass and primitive echo sounder for depth, and often found said lost gear, i.e navigated "blind" to within an few hundred yards after a storm. They just knew where they were. I've spoken to some of these old boys and I generally believe them. "

    Not very long ago, I posted a message right here on NavList where I pointed out that every good tall tale and a great many works of pure fiction begin with the phrase "this is a true story". And what do you know! Here you've gone and done just that, Francis. :) You have begun with the phrase "there are multiple confirmed stories" and that serves its purpose: it conditions the reader to believe the veracity of the following lines with reduced skepticism. Why, yes, of course it's true! Didn't he just say that these stories were "confirmed"?? And heck, you conclude by telling us that you've spoken to "these old boys" (they can't be wrong if they're "old boys," right?), and you believe them. True story!! 

    Ha ha. Of course, I'm teasing, Francis, and you know the problems with stories like these as much as anyone. First, we have to take them as heard, after the fact. We have zero actual evidence of how much effort those fishermen put into finding their nets nor do we really know what tools they used to navigate to them. Maybe they dragged for them all day long... but it's a much better story if you can say you went right to the lost nets without any effort. And I bet they caught an extraordinarily big fish that very same day, too! The second problem is more serious, and that's a type of confirmation bias. We remember our lucky successes and we ignore our far more frequent unlucky failures. We all do this, and it is a huge problem in any scientific endeavour --and yes, making claims about human beings' ability to blindly navigate to objects is science, it is not miraculous or magical. Those fishermen can get lucky. If they are unlucky, do we take note?

    You added:
    "The Polynesians seemed to know a thing or two as well."

    Of course the Polynesians knew a "thing or two", maybe even three things, but this doesn't mean they were magical navigators or even unusual navigators (in the position-finding sense of the word "navigator"). There are no new tricks under the sun for long-distance traditional navigation. As we speak, the Hawaiian ocean-sailing catamaran Hokule'a is making a tour of the east coast of the USA, and they're telling anyone who will listen about their "traditional" methods of Polynesian celestial navigation. But there's not much tradition in it all. The celestial methods they're using have been developed by modern Micronesian and Polynesian navigators in the past few decades in an effort to reconstruct an imagined form of long-distance navigation. They're plausible methods that navigators might have used centuries ago... or maybe not. It's also plausible that Polynesians sailed in some chosen direction and simply continued until they hit land or until supplies ran low. There's precious little evidence of long-distance trade in the pre-colonial Pacific yet plenty of evidence in local archipelagos. This historical reality does not support theories of significant long-distance Polynesian navigation.

    You added:
    "The famous or infamous Slocum only did one lunar for longitude, but was within 5 miles of his DR after 40 days at sea! Some DR that."

    Well, so he claimed, but he was a cocky, boastful man in an era when all men were expected to be cocky and boastful (in fact, by the standards of his own time, Slocum was down-right humble, but by the standard of any other era, no... boastful). Slocum's proof that his DR and his lunar were as accurate as he claimed was sighting the island of Fatu Hiva in the Marquesas. This is a mountainous island whose high peak is visible from some 60 miles across the ocean. Hardly an exact check on position. Slocum did, however, marvel in a letter home the following year about his own feeling that his reckoning always seemed to be dead on, each arrival on the day he expected. He himself could not see any of the explanation which seems so obvious today: he was no longer a merchant mariner on this voyage working by a schedule; he was the first global yachstman, and he sailed when he wanted to, in good weather, and in the best sailing seasons. Needless to say he also used his sextant every clear day for latitude and apparently he kept his dead reckoning with the usual diligence of a 19th century navigator using that famous small tin clock to record the hours spent on each heading.

    Francis, you added:
    "Maybe us humans still have some vestigial evolutionary ability to navigate by some hidden and largely lost mechanism, preserved and honed by just a few?"

    Yes, and maybe some of us have ESP... Remember the 1970s when that was oh-so-fashionable?? Even vestigial evolutionary abilities still have to make some evolutionary sense. What caused those capabilities to evolve? None of our ancestors were migratory (in the sense of long-distance bird migrations). They spread acros the continents like ink diffusing in water, but they did not migrate. On the other hand, we are descended from foragers, hunter-gatherers. Therefore there was some considerable evolutionary pressure for a basic ability to "close the box" navigationally, that is to be able to go out in one direction from base camp for a few hours, then turn in a different direction for a while, then maybe a few more legs, and eventually be able to "instinctively" return to the starting base camp. There is a plausible evolutionary pressure there, and we should expect that humans may have a natural ability to do that: to close the box of a very basic dead reckoning model. Note that this is utterly irrelevant to long-distance navigation, and also note that it is merely a plausibility model. Also note, too, that it is utterly ridiculous, despite some recent media reports, to suggest that such native abilities (if they exist) are atrophying "because of GPS and smartphones". Bashing the latest technology is always oh-so-fashionable.

    You concluded:
    "If Monarch Butterflies can do it, maybe we can too?"

    See, this is how these stories go off the rails. If monarch butterflies can do... what?? These butterflies appear to have an extremely limited ability to get direction from the Sun and a very basic ability to measure elapsed time helps in that. But that's all they're talking about in this story. And then the story gets re-told by media, and suddenly we go from basic direction-finding to "solving" the mystery of monarch butterfly navigation. Surely every NavList reader can see that you cannot reach a single region in Mexico from any location in the northern USA and Canada just by following the Sun! That does not solve the problem of monarch butterfly navigation, and it's not even clear that there is a problem of butterfly navigation. The Wikipedia article on this topic covers it nicely: https://en.wikipedia.org/wiki/Monarch_butterfly_migration.

    Frank Reed
    Conanicut Island USA

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