A Philosophy of Vertebrate Pest Control

Vertebrate pest problems are foremost economic, po l i t i c a l and social rather than b i o l o g i c a l anomalies. Students are often turned away from vertebrate control, which is a p p l i e d ecology, by professors who know only theory and do not understand the ecology of man-modified environments. Applied ecologists seeking alternative methods of vertebrate control benefit environment far more than the negative, anti-control approach based on halftruths that are used for self-serving purposes by many protectionist organizations and government leaders in CEQ, EPA and USDI. A healthy ethic, wi th deep ecological conscience, would be to appreciate the glory of death in nature, for death means l i f e to other i nd iv id uals wit hi n a species. A vertebrate control operation has benefit factors other than the i n d i v i d u a l or species being controlled, whereas the objective of w i l d l i f e management favors the w e l l b e i n g of local populations of the species in question. Since Land-Grant U n i v e r s i t i e s are geared for research and extension support from the USDA, it is a mistake to have the r e s p o n s i b i l i t y for vertebrate pest control in the conservation-w i l d 1ife-management oriented Fish and W i l d l i f e Service of USDI. I am pleased to give this paper as a substitute for a speaker who had to cancel. Slides w i l l be shown during half of the talk to illustrate my philosophy and give examples of consultations on rodent control overseas. Decisions about vertebrate pest problems should be developed from a deep appreciation of the need to protect and preserve w i l d l i f e , balanced by recognition of the importance of w i l d l i f e management, and guided by a healthy understanding of the ecology of vertebrate pests in environments that man, wisely or unwisely, has modified for hi s own well-being. Most b io lo gi sts, however, seem to lack basic knowledge about the ecology of disturbed environments. My experiences as a consultant have widened and deepened my philosophy of vertebrate control in particular. It has been my good fortune since 1969 to have had 10 short-term consultantships w i t h the United Nations (Food and Agricultural Organization or World Health Organization) on vertebrate pest problems i n v o l v i n g rodents, European rabbits, deer and other introduced mammals, vampire bats, and other species. These assignments have ranged in duration from about two weeks to s ix months. I have also had F ul br igh ts to New Zealand and A u s t r a l i a and a second year-long assignment to New Zealand. I continue to learn much w i t h each new assignment, not just about the people-problem aspects of vertebrate pests, but also about w i l d l i f e ecology in disturbed environments. Nature is not only a l l in cl usi ve but abounds with more confusion than many ecologists are w i l l i n g to admit, in particular when it comes to problems of vertebrate pests. Perhaps of greatest importance, my foreign experiences have dramatically demonstrated that almost a l l vertebrate pest problems are foremost economic, p ol it ic al , social, and even religious problems rather than biological anomalies. They are p r i m a r i l y people problems-created by people and d i f f i c u l t to handle m a i n l y because of the human relation involved. I try hard to get this philosophy across to my students before they leave their academic sanctuary. Too many people, unfortunately, develop a professional syndrome in which, being h i g h l y trained in theory, they lose s en si ti vit y to the practical world of reality. That vertebrate problems are mainly economic and political, not biological, is d i f f i c u l t to get across to many people. Unless students are also exposed to the practical reality of nature in man-altered environments, they u s u a l l y are prone to th in k that vertebrate pest problems can be solved by a p p l y i n g textbook theories they learned in college. Unfortunately, they u s u a l l y learned these theories from professors who have l i t t l e understanding of the ecology of vertebrate pests because they, too, mostly were taught no more than theory. To discuss vertebrate control l o g i c a l l y , in t h i s country or abroad, one must recognize some of the current misunderstandings about the ecology of animal control. Where man modifies natural environments, he changes the types of habitats present, d i sr upt ing to varying degrees the cycle of renewal of life. To f a i l to recognize the need in these altered environments to protect and manage some species and control others is to ignore the basic p rin ci pl es of the balance of nature. The h o l i s t i c science of ecology has demonstrated the interdependence we and a l l other organisms have w i t h each other and w i t h various resources. 116 Contributions to the quality of the environment are probably much greater from those few researchers who are developing safer and more selective means of controlling offending vertebrates than from the extremists who think the best solution is to outlaw all existing rodenticides, avicides, and predacides. When such toxicants are outlawed without alternative nonlethal methods of control, it usually merely forces the public to adopt whatever "environmentally disruptive" control methods they can devise, legal or illegal, with the environment being the scapegoat. Too many current ecological and wildlife textbooks attempt to stress the balance of nature as if it is a delicate balance between individuals, and imply that man should let nature resolve the vertebrate pest problems. Most of them still mistakenly suggest that encouragement of natural predators is the most effective way of controlling vertebrate pest species. Many also think that biological control methods, i.e., habitat control, should be a primary goal of all vertebrate pest control. Sometimes it is a good method, but we must remember that the trade-off with habitat modification is very disrupting to all other species of vertebrates. Whenever a field vertebrate species is managed by habitat alteration the suitability of the habitat will be changed for all species, thus affecting most nontarget vertebrates far more than even the careless use of poisons, traps, or shooting, which, as our keynote speaker Dr. Gus Swanson pointed out, usually affects only a few individuals, not populations. Many biologists fail to recognize that forest and range environments are actually quite stable as far as vertebrate species are concerned. An equilibrium has evolved between the wildlife species and the soil and vegetative complex. Removal of even a large number of individuals of one vertebrate species rarely has a measurable effect on the others. For example, if all of the deer, the dominant herbivore, were removed from North America, the effect on any other vertebrate species (except for a few wolves, mountain lions and coyotes) would be difficult to measure until the vegetation had changed through no longer being grazed and browsed by deer. Instability of an ecosystem results primarily from physically modifying the environment or introducing exotic plants and animals. Consequently, few agricultural crops or home gardens could survive if all native vertebrates were permitted free range in environments thus modified. Control of wildlife populations in man-modified environments is often a basic tenet in ecologically wise husbandry of our wildlife heritage, producing both tangible and intangible benefits to man and the environment. Most biologists, and even the new generation of trained ecologists, commonly do not react to vertebrate pest problems objectively, as a well trained biologist should, but instead respond more frequently to their emotions than to reality and the laws of nature. As Dr. Dale A. Wade pointed out to one of my classes, political and administrative influences on the direction and effectiveness of animal control problems are often thought to be clear and obvious but usually are not. It would not be difficult to focus control efforts on a specific and clearly defined problem, but seldom can all aspects of the problem be recognized unless one considers all related ecological and political factors. Initially it seemed to be just teachers of biology, conservation, and wildlife management who established such a critical atmosphere against vertebrate pest control that students were obligated to shun this area of training. Today, even though many students recognize the ecological significance of disturbed environments and the need for research on animal control, many preservation, conservation, and ecological organizations have joined the anti-vertebrate-control ranks. Some self-serving so-called protectionist organizations actually distort true facts to gain additional memberships or donations. Its unbelievable how much money can be raised by using these half-truths. However, we must recognize that nothing can be gained with closed minds on either side of the controversy, and a more constructive relationship is needed between control agencies and protectionists organizations. There is a lack of trust. Too many government officials in the Council of Environmental Quality, Environmental Protection Agency, Department of the Interior, and leaders of other organizations sit in unique and protected positions where they can orchestrate all sorts of distorted facts, thus creating serious problems for the control people. A consequence is a loss of credibility among workers in vertebrate pest control that is going to be very difficult to overcome. And too many people in prominent positions do this just for their own ego rewards, or for financial support obtained by stirring the emotional pots. Unfortunately, the environment often suffers in the end. It is very difficult to attack most political and philosophical conflicts about vertebrate pest control, because even if one does survive the attack the scars rarely fade.