Lloyd Loope reviews: A Field Guide to the Reptiles and Amphibians of the Hawaiian Islands. Sean McKeown. Diamond Head Publishing, Inc., Los Osos, California, 172 pp. $14.95 (ISBN 0-9650731-0-6 paper).
February (ed.:1997) has brought to light the discovery of two new alien species established in the wild on Maui -- both of them tree frogs (The Maui News, February 6, 1997, A1). I was relatively well prepared for this event since I had just purchased a copy of Sean McKeown's book, so I could calculate right away that Dr. Fern Duvall's discovery had increased the number of alien amphibian species in Hawaii from 5 to 7, and the number on Maui from 3 to 5. Additionally, the book helped me to understand why someone might have the arrogance, ignorance, or whatever it takes to purposely and illegally introduce a tree frog species to Maui.
This field guide is handsomely illustrated and is a very interesting book. It opens up a whole new world to the person interested in natural history of alien species in Hawaii. It provides fascinating details on the biology of each species, on care of the species in captivity, and provides distribution maps for each species in the Hawaiian Islands. Unfortunately, the book provides much eriudite-sounding misinformation on the "beneficial and benign" nature of reptile and amphibian introductions to Hawaii. I find this alarming because the book is appealing; many people will read it and become miseducated. And the author, who sadly probably really is the "foremost authority on Hawaiian herpetology," is said to be a bona fide conservationist who is "a working member of the International Union for the Conservation of Nature (IUCN)."
Author Sean McKeown does indeed recognize that a very few species (his "island supertramp" species) of reptiles and amphibians would be or are bad for Hawaii. After mentioning that there are 720 species of treefrogs worldwide, he states that "virtually all but a very few individual species of treefrogs would be both beneficial and benign if they were to be introduced in the Hawaiian Islands. Regrettably, the single species that has the capacity to do great harm to island ecosystems, the Cuban Trrefrog, is now present in Hawaii," having been illegaly imported from South Florida to Oahu in the 1980s. Strangely, McKeown just doesn't seem to grasp the concept that generalist species of tree frogs are likely to undergo population explosions in island ecosystems which are lacking in native tree frogs. These generalist tree frog species are going to depend on insects for their food supply, and some of them are likely to invade high-elevation rain forests where native Hawaiian forest birds depend on native insects for food.
The author goes on to say that there are over 2,500 species of snakes, "the great majority of which are non-venomous and beneficial to humans." He considers the Brown Tree Snake an anomaly. "Virtually all other snakes are specialized as to where they can live and what they can eat. Most snakes feed on rats and mice and benefit mankind." (Yes, those two sentences are in juxtaposition!) "No other snake has caused the extinction of a single species of animal anywhere in the world." Yet most of us wouldn't have heard of the Brown Tree Snake if it hadn't by chance been transported to the island ecosystem of Guam 50 years ago, established and spread over the island, and built up populations 10-50 times as large as in its native habitat.
Regarding the potential impact of invasions in Hawaii, we are only beginning to realize the potential consequences. Transport of heretofore obscure species from place to place is accelerating at an alarming rate. I do not believe Hawaii's laws are sufficiently restrictive to prevent further devastating alien introductions, yet all snakes and most tree frogs are prohibited, as they should be. Unfortunately, it may be the person whose conscience is soothed by the misinformation in McKeown's book who breaks the law and smuggles in the snake species which establishes in Hawaii and wreaks havoc.