Wild Thing: Of Crazy Ants, Kudzu, and West Nile Virus

Wild Thing is an occasional series where JHU Press authors write about the flora and fauna of the natural world—from the rarest flower to the most magnificent beast. 

guest post by Russell F. Reidinger, Jr.

racoonRaccoons work hard to get into attics, sometimes destroying siding or roofing materials along the way. Once inside, raccoons may damage electrical boxes, wiring, or plumbing vents, or spread disease. Most raccoons strongly resist eviction, especially if they have young. Trying to get raccoons out, especially whole families, can take planning, resilience, and work. And, even with success, raccoons may try aggressively to get back in. Given that raccoons can bite and scratch, and the uncertainty of diseases, the better strategy might be to get professional help.

In retrospect, most homeowners have who experienced raccoon invasions would probably agree that preventing access to their homes would have been preferable to removing the raccoons. Regardless, raccoons in attics are mental images that often come to mind when thinking of wildlife damage. So are images of squirrels in attics or skunks under porches or deer jumping in front of cars.

But images of some animals—the crazy ant, for example—do not typically pop up when we think of wildlife damage. Yet crazy ants cause extensive damage to island ecosystems. Called “crazy” because of their erratic movement, the ants can form colonies in tree canopies and tolerate multiple queens. Supercolonies with 300 queens have been discovered. The ants are voracious omnivores that eat grains, seeds, and detritus. They “farm” scale insects and aphids. So, where is the problem? The ants spray red land crabs with lethal amounts of formic acid, then eat the protein-laden crab carcasses. Crazy ants have killed 15 to 20 million crabs since the late 1980s on Christmas Island alone. The absence of the crab, formerly a keystone species for the Islands, has caused dramatic changes in litter cover and species richness, along with a concomitant decline in some endemic species.

Kudzu_field_horz1Kudzu, also called “the vine that ate the South,” is another example of wildlife that causes damage. Brought to the United States from Japan for the 1876 Philadelphia Centennial Exposition, the vine was planted widely in the eastern United States for erosion control. Kudzu is now prominent in many southern landscapes, where its vines can cover entire canopies, telephone poles, or abandoned houses. The covered landscape provides a green, ghostly appearance from a vantage over the canopy, but suffocated native vegetation lies underneath. Kudzu carries soybean rust fungus. While efforts have been made to use kudzu for products such as soaps and jellies, and it has even been the subject of poems, kudzu remains a serious southern ecosystem problem.

Hailing from the West Nile Province of Uganda, West Nile virus was first identified in 1937. It appeared in New York City in 1999. The disease, transmitted by mosquitoes,  infects many vertebrate species, but most are asymptotic. The movement of the virus in the United States tracked closely that of some migratory birds. Species such as blue jays seem particularly sensitive and serve as indicators of the disease. While many people infected with the virus show no symptoms, a few will get meningitis or encephalitis. In the United States from 2009—2010, the Centers for Disease Control reported about 1,700 human cases, with 69 fatalities.

One can question whether problems such as these are part of wildlife damage management. Are the species domesticated or wild? Do they affront humans or their interests? The answers can be complex. In fact, it is the principles and concepts underlying answers to broad questions such as these that are part of the real substance of Wildlife Damage Management. If you are looking for a step-by-step manual on how to remove raccoons from an attic, this book is not for you. If, however, you want to understand the biological, ecological, and human dimensional concepts underlying wildlife damage management as it is currently practiced (and, we believe, how it will be practiced into the foreseeable future), this is the book for you. We review characteristics of damaging plant and animal species in North America and around the globe; summarize physical, pesticidal and biological control methods; and emphasize traditional vertebrate pests with abundant examples. But we take the position that today’s wildlife damage management also includes invasive plants and animals and wildlife diseases and zoonoses. And we include some speculation on how wildlife damage started anyway, beginning with Australopithecus afarensis, a preman who served more as prey than predator. I encourage you read our book.

reidingerRussell F. Reidinger, Jr., is a former director, National Wildlife Research Center, USDA APHIS / Wildlife Services, and an adjunct professor in the Department of Agriculture and Environmental Sciences at Lincoln University in Jefferson City, Missouri, and in the School of Natural Resources, University of Missouri, Columbia. With James E. Miller he is coauthor of Wildlife Damage Management, published by JHU Press.

5 Comments

Filed under Biology, Conservation, Wild Thing

5 responses to “Wild Thing: Of Crazy Ants, Kudzu, and West Nile Virus

  1. Pingback: Wild Thing: Of Crazy Ants, Kudzu, and West Nile Virus | jhublogs

  2. Carol W.

    Great article. Do you also offers ways to combat kudzu growth? There are groups that use goats to reduce the invasive biomass!

    • Graham

      Goats? Interesting.

      Is there anything else, perhaps easier to obtain in an urban area, that would also do the job? Also, how much does it even matter that these plants are growing? I kind of like the look on old houses

    • Russ Reidinger

      First, thanks for reading, enjoying and commenting on the article! In managing wildlife damage, we often count success when we increase the human value of wildlife or when we diminish their negative values. Kudzu is a great example. It has been used for erosion control, as forage for livestock, to make baskets and medicine (it is listed as one of the 50 main herbal plants in its native Chinese), and has shown up in many a food recipe. All these uses give it positive value to people, not even counting its aesthetic appeal (see Graham’s comments) to some (I like its ghostly appearance).

      But, the damage kudzu causes native plants and ecosystems is also undeniable. By some estimates, kudzu is claiming an additional 150, 000 acres each year, and is now found in Canada in addition to the United States. The costs to ecological services are negative in the eyes of many. In Tennessee, goats have been used to help clear kudzu from walking trails in park areas near Knoxville, and along high ridges of Chattanooga. In these examples, native vegetation takes precedence over the invasive kudzu. Others have used other methods to manage kudzu. Repeated mowing sometimes works, as can prescribed burning, bulldozing, and herbicides.

      Regardless, kudzu illustrates another important point in managing wildlife damage. Damage is a human concept. People are unlikely to agree on what constitutes it. That is part of what makes managing wildlife such an exciting challenge.

  3. Desiree Lyons

    Kudzu isn’t all that bad — there are many uses for it, ie basketweaving. I’ve also heard it can be used in foods and medications