The More You Learn, the Less You Know

by Conrad Vispo

Published Spring of 2008 in Our Town


Not the best school motto, but nonetheless, a truism. Actually, I find it inspiring. After all, it is the search for buried treasure that motivates researchers. But humankind has accumulated so much information that it’s sometimes hard to believe there is anything left to learn, which can be discouraging to an aspiring explorer. As a contribution to the documentation of our ignorance, and with the hope of stoking the embers of curiosity, I offer this brief essay on what we don't know about the animals with whom we share our landscape, except that what we don't know is surely much more than I can even imagine.


Let's start small. Really small. Microscopic creatures are easy not to know. Their effects--rotting wood, steaming compost piles--may be visible, but they themselves are not. Someone once estimated that the biomass of underground microscopic organisms may exceed that of organisms who roam the surface. Some of these, for example, fungi, periodically become visible, and some are only debatably animals, but the point is that there is a vast, underground world teeming away out of view. There are surely thousands, if not hundreds of thousands or even millions of species of microscopic organisms going about their daily lives under our feet. They are the largely unsung support crew for many of our plants--mineralizing rock, capturing nutrients from the air, and forming strange collaborations that help plants collect solubles from the soil.


Explorers of the underground realm are only beginning to discover it. Methods are now available that allow us to begin to catalog residents, but in most cases, we haven't the foggiest idea what these creatures are doing. It's as if somebody handed you a very incomplete list naming the animals in a forest, but you had no idea which ones were birds, frogs, mammals or ants and were nearly clueless about who ate whom or what. Under the ground we are only beginning to realize that the equivalent of rabbits aren’t fleas, and turtles aren’t rocks.


We have come up against this corner of the unknown in our work with farmers, here in Claverack and elsewhere in the county. They want to know if they’re using their grasslands sustainably. Or, more precisely, how much can they graze or hay a field without slowly robbing it of its nutrients and degrading the soil into near sterility?


This is not as straightforward a question as it might seem. Our grasslands are not passive pools of nutrients depleted by harvests and restored by fertilizer. They hum with life, and that life helps plants grab nutrients out of the air and scrap them from the rocks. So, the question is really this: At what rate are these on-the-scene workers gathering nutrients relative to the rates at which we are removing them with our harvests? And more important, is there anything we can do to make their job easier? The answer is, we hardly know. The beam of our flashlight has fallen on only scattered corners of the underworld arena.


But surely we know more up here in the visible world, no? Well, yes, we know a bit more about say, bees than we do about microbes. We know that there are probably something like 400 to 450 species of native bees in our state, although there are surely still species left to discover. But what are all those bees doing? Where do they live? What, if any, pollen and nectar do they seek? How do their lives interact with ours? Given the recent concern over the fate of the Honey Bee (which was introduced to our continent by European colonists), it is amazing to realize how little is known about the other bees who, though they rarely make honey, can be important pollinators. For most species of bees, we have no idea whether their populations are nose diving, rocketing upwards, or are relatively stable.


Our own work, in collaboration with Martin Holdrege, is a small contribution to the knowledge of bee pollination of crops on local farms, including at least one in Claverack. When added to information gathered from the few other wild bee researchers in the Northeast, it might provide us with a better understanding of what all those bees are doing. If we can learn which bees are most important for the pollination of which plants, then perhaps we can begin to better manage our land for the well-being of those species. Right now, our understanding of bees and their ecology is probably equivalent to what Audobon knew about birds. We know some things, but there is an immensity still to learn.


Our unknowing extends to all insects. We are not even sure, for example, if some of our most showy butterflies, such as the Tiger Swallowtail and Pearl Crescent, are single species, or two or more look-alikes. One of our most gorgeous butterflies, the aptly named Regal Fritillary, has completely disappeared from the region over the past 50 years, but there are only wild guesses as to why that happened. And then there are the ants (probably 60 to 70 species in New York), spiders (around 700 species), beetles and moths (thousands). The numbers of these organisms is daunting, their ecological role likely huge, and the number of people studying them, pitiful.


But the frontier of our knowledge is hardly over the horizon even when it comes to such seemingly well known species as frogs, birds, and mammals. Take the Wood Frogs and Spotted Salamanders who show up at many local pools in the spring. Their early-April orgies are conspicuous, and so where and when they breed and lay their eggs is fairly well known to us. But what do they do the rest of the year? Where do they forage in the summer? Where do they sleep in the winter? We have some rather precise physiological knowledge of how Wood Frogs freeze (and survive to unfreeze) in the laboratory, but we have very limited knowledge of where they pass the winter in the wild. Likewise, Spotted Salamanders are part of a group called mole salamanders, and yet we have only glimpses of whose holes they use, how deep they travel, and what, if anything, they do while underground.


Birds are perhaps the best known group of animals, simply because so many people watch them. The dedication, expertise, and prevalence of birders is legion and inspiring. And yet, and yet. Bobolinks are raucous summer residents of our late-mown hay fields. At the right place and time, they are hard to overlook as males jockey for females, and later in the year the fledglings stumble into the air. But where do they go during the off season? Southwards surely; Bolivia and Argentina probably. A friend recently went in search of their winter quarters. She found a few birds, but I don’t think she came close to convincing herself that she could state with certainty where all Bobolinks overwinter.


And what about shrews? Short-tailed Shrews are the size of a mouse; with their tiny eyes and grey velvet coat, they are often mistaken for moles. They are also, to add an exotic twist, one of the world's only poisonous mammals. Not to worry; their saliva has little effect on us, but what is it about the lives of these animals that makes poisonous saliva so useful? Cat owners may see the occasional short-tailed shrew among the offerings on their doorsteps, but the nether-reaches of the shrew world are the Sorex, or long-tailed shrews (Sorex is their scientific name, apt for a small creature with a pointy nose.) They are some of the tiniest mammals in the world. Our smallest local species weighs about as much as a penny, its heartbeat can exceed a thousand beats per minute, and when active, it must eat more than three times its weight every day. There is even a Water Shrew. Slightly larger, it lives along and feeds in small creeks. Diving into cold water seems slightly suicidial for an animal already living on the metabolic edge of feasibility, Does this species occur in Claverack, or anywhere in Columbia County? We don’t know. Few, if any of us, have ever seen one. Sorex could wink out of local existence and nobody would notice, at least not directly.


This possibility of indirect effects brings us to the final aspect of the unknown-- the complexities of the ecological web. How do species interact?  


A recent feature on NPR revealed the role that wolves play in controlling stream erosion at Yellowstone. Apparently, the wolves scare elk into spending less time browsing streamside willows, which allows the willows to grow up. The willows, in turn, stabilize stream banks. While we currently have no breeding population of wolves or elk in the county (although we probably did once), we do have coyotes and white-tailed deer. The role of deer in the alteration of forest composition is well documented, but how do increased coyote populations affect the patterning of ‘forest management’ by deer? What aspects of the “natural” appearance of our landscape are actually reflections of this complex interaction which certainly includes us as actors? That one animal eats another is obvious, but when one species subtly changes the behavior of another, few of us have the time or the inclination or the powers of observation to notice.


And how about the interactions of ants and butterflies? One family of butterfly, the Blues of Nabokov’s study (represented locally by Azures and Hairstreaks) have developed interesting relationships with ants. Somewhat like aphids, the caterpillars of certain species are tended by ants. The ants glean a sweet liquid from the caterpillar and in turn, appear to protect the caterpillar from predators. But the plot thickens. In some cases, the ants appear to be so taken by the caterpillars (thanks to some tricky caterpillar chemistry) that they even carry the caterpillars in and out of their nests, thereby protecting the caterpillars when they are not feeding. In Europe, it appears that some Blues have adopted a Trojan Horse tactic that takes advantage of the ants’ hospitality. When brought into an ant nest, the caterpillars of these species begin to eat the ant larvae. Does this happen amongst any of our local species? I asked one of the most knowledgeable Lepidopterists I know. His answer: No idea.


And finally, rabbits. Most of us see rabbits regularly, and yet the only county mammal currently under consideration for Endangered Species status is a rabbit—the New England Cottontail. “On the hoof,” the New England Cottontail is nearly indistinguishable from the Eastern Cottontail. Fifty years ago, New England Cottontails abounded in the region; A hundred years ago, Eastern Cottontails were nearly unknown east of the Hudson River. As a result of expansion into changing habitats, fueled by human introduction, the Eastern Cottontail has spread throughout the area, and the New England Cottontail has virtually evaporated. Today, all (or at least almost all) the rabbits around us are Eastern Cottontails. Do the two species compete? Is our hand in changing land cover playing a major role? Might New England Cottontails still live in Claverack? We can only guess. (Based on surveys that others have conducted regionally, the answer to the last question is probably ‘no’, but I’d gladly inspect any rabbit skulls found in the woods, as the two species can be differentiated by skull traits.)


Not all of these unknowns (a very partial list) may seem important from a human perspective, but how can we know what’s important, when we don’t even know what’s happening? Furthermore, the needs of our own species can’t be our only criteria of importance. Yet we can’t evaluate what might be important to other species, when we barely grasp their natural history. This is hard to believe in a time when so much information is available at the click of a mouse.  But the Age of Complacency seems to have followed the Age of Discovery, at least in the field of natural history. Books about animals are bursting with details of the known, but if I ever get around to publishing my “Idiot's Guide to the Unknown,” it will be filled with blank pages.