Exotic species cause problems for natives

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Among the best commentaries on critters I have ever read was one published by the editor of The Missouri Conservationist that appeared in the August, 1984 issue. It was titled, “Tolerating the Unlovely.” Excerpts follow.

“It happens almost every year, somewhere in outstate Missouri, the local newspaper carries a picture of some man holding a long snake by the tail and the cutline carries the story about how he killed the thing. Most people will read the item with perhaps mild approval, and put it out of their minds.

“But not everyone. Tom Johnson, who is a herpetologist with the Department of Conservation and an extremely sensitive man, will read the article with a little anguish. Tom, who has taken the time to learn about snakes and understand them, mourns the loss of a valuable bit of the natural world.

“Tom’s concern in the varied tapestry of the Missouri outdoors is with snakes, frogs, toads and salamanders, none of them very lovely to most of us. Some of us like to hunt bullfrogs and dine on their legs. Other than that they are just there. We tolerate toads — they eat bugs. Salamanders are so seldom seen by most of us that we don’t have opinions of them.

“Perhaps we catch a hellbender in some Ozark stream and are repelled by its hideous, slimy appearance. But beauty is in the eyes of the beholder, and the hellbender is eagerly sought by some researchers, to whom it is a unique and fascinating creature. Of course, the unlearned consider it poisonous, which it is not. To many, all ugly creatures have to be poisonous.

“Of course, no one wants to live close to a timber rattler. But a rattlesnake in some remote forest setting belongs there and seeing one is not an invitation to kill it. It isn’t going to attack unless provoked. Why not step around it and consider yourself fortunate to have met this link with our primordial past? … Most of us who roam the outdoors have tales to tell of our encounters with snakes.

“Meeting a venomous snake in the wild is a signal event, an adventure… Their death is not necessary to our story.

“We tend to place value judgments on everything, and the unlovely creatures rate low in our esteem… The bat (is ugly) but it is being studied for circulatory and heart applications. The unlovely opossum offers medical science studies on gestation and development of embryos. Who knows which unlovely creature will next provide us with valuable information?

“Much better to withhold judgments on the wild. It was here before we were, and its existence is justification enough that it has a role to play in the creation. The natural world is so filled with wonder and mystery that our ‘instinct’ to kill the ugly or unknown robs us of a chance to learn. As humans, we ought to be beyond that.”

The author was obviously advocating conservation of native animals, elements of our natural heritage. It was written prior to the introduction of large numbers of exotic, invasive species into our country, some of which are posing threats to many of our native species. The red imported fire ant has had a devastating impact on many ground-nesting vertebrates and ground-dwelling invertebrates in much of the southeastern quadrant of the United States. Burmese pythons, numbering in the thousands, infest the Everglades and adjacent areas of Florida. Other large exotic predators have established breeding populations in South Florida, including African rock pythons, Nile monitor lizards, giant Argentine tegu lizards and common caimans, relatives of alligators.

These large predators are severely impacting wading birds and small native mammals inhabiting the Everglades. A recent study revealed declines of more than 90 percent of the populations of a wide variety of small animals in the infested area, including raccoons, opossums, rabbits, and bobcats. A total of 137 non-native amphibians and reptiles now occur in Florida, more than in any other place on earth. Species known to have established breeding populations in Florida include 43 lizards, five snakes, four turtles, three frogs and one crocodilian, the aforementioned caiman.

Kenneth Krysko, a herpetologist with the University of Florida, was quoted in the most recent edition of Explore, saying, “It’s like some mad scientist has thrown these species together from all around the world. It could take decades before we know the long-term effects these species.” Efforts are underway to reduce the numbers of the species causing the most serious problems, but they may be too little too late.

On a positive note, the problems Florida is experiencing with the invasive exotics may ultimately result in increased employment opportunities for professionally trained field biologists.

Bob Mount is a Professor Emeritus with the Dept of Zoology and Entomology, Auburn Univ. He is also chairman of the Opelika Order of Geezers, well-known local think tank and political clearing house. He writes about birds, snakes, turtles, bugs and assorted conservation topics.

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