Languages of Nature


Frederik Sjoberg’s entomological memoir The Fly Trap deserves much better than my month late musings, but here they are.

The titular fly trap is the Malaise trap, an essential piece of entomological collecting equipment devised in the early twentieth century by the Swede Rene Malaise, when he noticed that flies had a tendency to collect in the highest corner of his tent.  Malaise made several extraordinary collecting journeys, to Kamchatka and Southeast Asia, and uncovering something of the man is one of the driving forces behind Sjoberg’s book.

Sjoberg’s own interest is in one way the polar opposite of Malaise’s: for years Sjoberg collected only on the island of Runmaro, not far from Stockholm, and mostly in his own garden.  He found more than two hundred species of hoverflies in this way, these being members of the widespread but rather inconspicuous insect family Syrphidae.  Some of these harmless creatures are very convincing mimics of wasps and bees, which is a source of amusing aggravation when the entomologist is accosted by ignorant summer vacationers.

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Insect Collection, from Wikimedia Commons, CC BY David McClenaghan and CISRO

It bears remembering that in common with many other insect taxa, there remain many things about the life history and distribution of hoverflies, and no doubt many species, that are unknown to science.  Many of Malaise’s specimens lie unsorted in museums to this day.  Hence it is possible for the dedicated hobbyist (it’s not clear but I gather that Sjoberg supported himself with translation, and perhaps the civility of the Swedish state) to make real contributions that are truly appreciated by a small community of specialists.  Amongst them, memories are long and the appetite for new reports tremendous; after a long summer of collecting Sjoberg describes settling in for the winter with his cabinets and writing to his colleagues about his most interesting discoveries.

He talks about the Legendary Flies, and it’s really hardly funny at all; it’s awe inspiring, these animals that are seen twice in a century, if that.  He tells the incredible story of the Fly Tree, a giant which stood for centuries in a Swedish town until it was brought down with dynamite by insane government busybodies.  It was so named because every summer night it was surrounded by a cloud of flies, some of which are speculated to have bred only in pools of water that collected high in the trunks of ancient trees.  Where are they now?

Birds are my current pursuit in the domain of natural history, and I asked myself if there are legendary birds.  There have been so many people looking for the Ivory Billed Woodpecker that it’s very hard to believe that it’s not extinct.  Others, like the condors, whooping cranes, or Kirtland’s warbler, they are extremely rare, but, still, I think, more accessible than the Legendary Flies.  Something I have yet to attain to.  On the other hand, Sjoberg’s discussion of learning natural history the way one learns a language is, I think, quite widely applicable and accessible.  He has invested so much time in learning hoverflies because reading the Book of Nature is so pleasurable.  Simply looking is pleasurable as well, but that’s not all there is.  I’ve learned that one has to know at a glance many species of warblers to feel the full impact of a really busy day of spring migration.  One has to go out a lot, and listen carefully, to really appreciate the explosion of cedar waxwings in Boston in the first week of June.

I’m wondering what language I want to learn next.


Rocks with Guts

I’ve just read a book about freshwater mussel conservation.  While I’m sure I could just as well have read a similar book about frogs or bats or sedges, I’m pleased to report that Sarah Gascho Landis’ Immersion is a fairly decent example of the genre.  And mussels may just be especially weird, hence the quote in the title of this post.


Some freshwater mussels (U. S. Fish and Wildlife)

I’m a bit of an amateur naturalist, but I’ve barely paid attention to mussels.  Perhaps nondescript shells don’t seem very remarkable when they turn up on the banks of a slow moving but seemingly healthy river.  Or maybe studying them in situ doesn’t seem worth the effort.  Landis has some good stories about that, searching for mussels in rivers choked with (sometimes full) beer bottles, dead cats, or simply a big snag that seems determined to drown someone.  What I find interesting, though, is the mollusks’ ability to hide and turn up in the strangest places or under the worst circumstances.  I still remember finding a huge black crawdad crawling through the grass on a rain soaked roadside.  Mussels have a similar ability to push the boundaries of their aquatic habitat and run up against our terrestrial ways.  I’m fascinated by the idea of hundred year old bivalves in the deep eddies of tiny, rocky creeks far up in the mountains.  There are even mussels that live in ponds!

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A mussel displays her lure.  (U. S. Fish and Wildlife)

How do they do it?  Fish, mostly.  Landis is apparently mesmerized by the mussel reproductive cycle, and it is pretty amazing.  Mussels don’t come together to mate; female mussels must capture free floating sperm from the water.  Once they have nursed a brood of baby mussels, many mussels rely on a fish to host the babies, and then release them elsewhere.  Lampmussels deploy an astounding minnow shaped lure to bring in a predatory fish and then reward them with gillsful of mussel larvae.  Some mussels have evolved the ability to defeat the immune response only of specific fish; overall, it’s a specialized and vulnerable reproductive strategy.  Fish, mussels, and thousands of tiny streams throughout the piedmont region of the American southeast have somehow combined to produce a hotspot of unrivaled biodiversity, including some three hundred mussels species.  I wish Landis had tried to say a little more about the long term evolution of the group; it seems like it would be a fascinating story.


The Tennessee-Tombigbee Waterway is a massively disruptive 200 mile link between the Tennessee and Mobile Rivers

Lately mussels have taken a tremendous amount of abuse.  Droughts, water pollution, and the complete restructuring of watersheds are taking an even greater toll than the freshwater pearl and button crazes of the late nineteenth century.  Of the three hundred or more species of lampmussels, snuffboxes, pigtoes, pistolgrips, etc., dozens are federally listed.  Landis has a few heartening stories of mussels rebounding in habitats that were completely dried or polluted to death.  Often these successes came through a lot of hard scientific work (a mussel hatchery sounds like a daunting engineering project) and enforcement of environmental law.  Overall, though, the outlook does not seem good.  There are different ways of looking at this.  Landis presents the case that mussels are a convenient measure of the overall peril of water pollution.  She also writes movingly in a more personal register of the intrinsic value of biodiversity.  She says that learning to see mussels is like discovering a hidden library.  Even if I never see more than a handful of these species, I know that I want to live in a world that boasts of these strange “rocks with guts”.