People down at the "J and B Market" talk of 'coons and the need for stocking them. A lost ring-necked pheasant, an introduction from China years ago, wandered across the road as I drove to the cabin. What is the fascination? Why is "getting new" viewed by so many people as being better then "improving the present?"

A popular technique within the array of techniques available to people interested in wildlife management is stocking or introducing animals. An exotic is an animal introduced from outside its known natural range; a transplant is one moved within its native range, but into an area where it may never or no longer occurs naturally. Exotics and introduced species are discussed in the same terms, generally as "introduced species." An introduced plant or animal is one moved from one place to another by people. There are some notable examples of introduced animals that have become successful game animals. Fish of a wide variety have been successfully stocked for food and as game. The successes are spectacular. Hidden behind and among the successes are a variety of problems. These are difficult to see in the bright lights of successes. If the manager or public perceives no problems, then no problems exist! This is not so. There are many problems, and they must be perceived to be avoided. Perception and informed action can prevent the best intentions from going awry.

I think the problems have been poorly accounted or understood in the past. The potential benefits, also conspicuous, will be listed. The question of whether (and if so, when) to stock is one of the most difficult to answer within wildlife management because of these conflicting lists of benefits and costs, both of which have very uncertain probabilities.

Sindermann (1986) described a frustrated group once proposing the "International Decade of Indiscriminate Oecological Transfers." It would be called project IDIOT and would hasten to stir up all ecosystems by vast transfers of everything. After a century, when everything had more or less settled down, after all of the ecological disruptions had been observed and adjustments made, then there would be no more need for regulations, customs inspections for disease and pests, enforcement, or meetings to discuss the problems of introductions! It was a well-named proposal! It was facetiously proposed to be a 10-year project. I fear society has agreed on the concept but extended the time. They had a good name for it.

There are few certain problems with introductions, only risks of costs and unfortunate situations, now and for the future

"It is important that all persons involved with the study, conservation, and management of resources recognize that any introduction requires a readjustment. Readjustment may be minor or imperceptible, or major. Perturbations may occur, sometimes decades after the introduction ... Living resources may not behave in new environments in a manner that we expect or predict, and therein lies a major part of the risk factor. Furthermore, introductions have been implicated in and sometimes proven to have been responsible for the decline and extinction of native species..." (Courtenay and Taylor 1986:31).

These problems include:

1. Initial disaster failure of the effort and thus only costs and no benefits
2. Potential disease and parasite transmission to native species
3. Reduction or destruction of indigenous species
4. Managerial neglect of native species
5. Shifts in populations and thus harm to some users or user groups
6. Stunting of some populations
7. Hybridizations
8. Escapes and difficult (costly) containment, and
9. Degradation of the environment (as by carp in some aquatic areas and by grazing animals producing
barren land in terrestrial areas).

How can the wildlife resource manager of a country or region tell when introductions or transplants are appropriate? The main criteria are:

1. The proposed exotic must be needed and have a desirable ecological, recreational, and economic potential
2. It should fill a vacant niche
3. It should not cause a drastic reduction of indigenous species
4. It should be preceded by studies of the ecology of the animal and these should guide the introduction
5. Disease interrelationships should be examined and, if necessary, a quarantine established. (Parasites are almost impossible to eliminate on or within imported animals.)
6. Trial releases should occur
7. A control mechanism must be available to prevent over-population from the final release. (The above was based on Kohler and Courtenay, 1986:34.)

The benefits typically expected from introductions are to the extent the new species achieves stated objectives. These may include:

1. They consume pests such as harmful insects
2. They become game or furbearing animals
3. They supply food for humans
4. They consume and control plant weed species
5. They become forage for carnivorous animals
6. They provide great esthetic beauty (e.g., gold fish in ponds or waters)
7. They diversify human and wildlife food
8. They provide a recreational opportunity
9. They fill new areas or waters, creating a resource where none existed.

The needs for a introduced-species program in a region or by an agency are:

1. First, to get the management system fully under control for all native species
2. To use local species or strains to create new strains that may meet needs
3. To establish quarantine procedures and enforcement to prevent transmission of pathogens or parasites
4. To develop a full information base (sometimes with new research) on candidate species
5. To develop a comprehensive genetic background and data base.
6. To develop models and computer-aided systems to estimate the full array of consequences of an introductionon associated species, the environment, and the human users, communities, and their social and economic structures
7. To develop regional and international consultation and agreements for action in cases where a species spreads beyond its targeted area. The Indo-Pacific Fisheries Council is one such group that concentrates on exchange of information about fish species. Action to control species transfer is very difficult, both in concept and practice.

Perhaps education is one way, but this seems long-term and the evidence is that it is highly ineffective. At least it needs to be tried at different levels. A comprehensive system is needed that establishes law (partially as education), establishes rewards and incentives for not doing it (reducing the appearance of need or making introduction seem practical), provides immediate action to reduce problems that might allow a need to arise, rewards effective customs work and enforcement, keeps on general pressure for a concept of "local is good," and makes clear assignment of all costs (as from a forest fire) if problems arise from the introduction (making the risk "dollar clear"). Many introductions are virtually irreversible, making cost assessments almost meaningless because they bankrupt a family, a society, a world … forever

8. To develop regional (state and provincial controls) over live imports, at least to assure information is available
9. To develop a protocol for introductions including:

1. establishing an informed commission or decision body
2. submitting a descriptive proposal for introduction detailing all known objectives, benefits, risks, and consequences.

Included should be:

1. objectives and basis for proposal
2. rationale
3. plan
4. risks
5. economic consequences
6. social consequences
7. political consequences
8. life history and niche
9. competition
10. predation
11. carrying capacity
12. relations to community diversity
13. genetics
    • hybridization
    • change in gene frequency
    • change in disease resistance
14. behavior
    • interaction with other species; pest potential
    • migratory
15. pathology
16. alternative options with native species
17. bonding plan (10 years) by the proposer
18. plan for eradication in event of undesirable consequences in first 10 years

As negative or as risk-averse as these requirements may sound, I'm not opposed to introductions. I am, however, for orderly, informed, rational introductions that provide society with a very high expected net benefit. The barriers before introductions should be reasonable, but they should exceed the complications that might arise from a failure afterwards.