Readers’ wildlife photos

While sitting at the airport, I just received a few animal photos from my old friend Peter, who once spent several years in Africa. It’s an unusual gathering of springtails in New England. Peter’s notes are indented:

This is a large group of Collembola crossing a dirt road in New Hampshire. I estimate the arc to be about ten or twelve feet long. However, in terms of the number of individuals on the move, this is like the sort thing one might see on the plains of Africa, only with wildebeest. It will probably take a couple of hours for them to cross the road.

The phylogenetic position of springtails seems to be somewhat controversial. They are arthropods (phylum Arthropoda), but it’s not universally agreed that they’re in the subphylum Hexapoda along with other insects. They could be a sister group of Hexapods but not nested within the Hexapoda. At any rate, here’s what a springtail looks like close up (photo from Wikipedia). And as you can see from the photo above, they’re small—at most a few mm long.


Your question: Why did the springtails cross the road?



  1. GBJames
    Posted May 22, 2019 at 8:50 am | Permalink

    It is a travel strategy that probably works better in the forest than on a road. I would think that most of those guys will end up as little more than a smear.

    • Dominic
      Posted May 22, 2019 at 10:38 am | Permalink

      😦 I hope not…

  2. rickflick
    Posted May 22, 2019 at 9:03 am | Permalink

    I wonder why they’d travel as a group?

    • Draken
      Posted May 22, 2019 at 10:20 am | Permalink

      Why, group discount of course.

      • rickflick
        Posted May 22, 2019 at 11:28 am | Permalink

        If it’s Tuesday, it must be the other side of the road.

  3. ThyroidPlanet
    Posted May 22, 2019 at 9:07 am | Permalink

    I’ve seen springtails up close – it’s maddeni because you can barely see them – and if I think about it, most things you can “see” you can see pretty good with the naked eye. Springtails are at the far end of that.

    My riddle answer(s) :

    – Hooke’s law
    – because it was summer
    – because their spring constant was too high
    – because they couldn’t weight

    … I am not a professional comedian.

  4. W.Benson
    Posted May 22, 2019 at 9:21 am | Permalink

    Large aggregations of Collembola do not seem to be unusual. Here is the abstract from a 1949 report:
    “In general, podurid and entomobryid springtails and oribatid mites are the most abundant arthropods in the litter of the forest floor and are important in the overall formation of organic soil (Allee, Emerson, Park, Park and Schmidt, 1949). On occasion, certain species of springtails have been reported as forming aggregations of almost incredible numbers of individuals. Elton (1927, p. 109), for example, states that swarms of collembolans are said to have held up a Swiss train, the minute insects covering the rails so heavily that the driving-wheels of the locomotive revolved ineffectually.”
    Orlando Park. 1949. A Notable Aggregation of Collembola. Annals of the Entomological Society of America, 42 (1): 7–9.

  5. Charles Sawicki
    Posted May 22, 2019 at 9:35 am | Permalink

    I suppose, like other animals, large groupings provide protection from predation. Seriously, it would be interesting to follow the horde to see where they are headed. If you do, report back.

    • Peter
      Posted May 22, 2019 at 10:20 am | Permalink

      Sorry, by the time I returned they had melted into the leaf litter on the side of the road.
      I see this kind of thing several times a year, but they are easy to overlook since they just look like a stain on the road after a rainstorm or something. For all I know, they may travel like this all the time, but in a lawn or in the woods you might never notice them.

  6. Debbie Coplan
    Posted May 22, 2019 at 10:23 am | Permalink

    Thank you for this post. I am embarrassed to say, I never heard of Collembola. Happy to hear about it now and see them in action.

  7. Posted May 22, 2019 at 11:09 am | Permalink

    Agree on the epic-ness of this migration. All we need are predatory mites and soil centipedes stalking the herd, looking for a sign of weakness or distractedness to exploit.

  8. randy bessinger
    Posted May 22, 2019 at 2:32 pm | Permalink

    Why did they cross the road…because it is there. One small step…one really small step.

  9. Christopher
    Posted May 22, 2019 at 5:29 pm | Permalink

    Anyone else see “…once spent several years in Africa” and thus misread “springtails” as springboks? No? Just me then.

    Sometimes it’s a wonder how I get dressed by myself in the morning. Well anyway, a lovely little story about a lovely little beastie. Podura are pretty cool relatives, a bit fatter and love water. They can coat parts of a pond shoreline in their grey stoutness. Observing micro-fauna like this is probably the closest I’ll ever get to the Serengeti experience but backyard safaris are nothing to stick your nose up at. Or at which to up your stick nose or whatever the proper English be.

  10. Rob Aron
    Posted May 23, 2019 at 10:26 am | Permalink

    Why did the springtails cross the road?

    To show an armadillo that it could be done, of course.

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