Resolving conflicts with Canada geese: an animal welfare perspective

The scope and significance of human conflicts with urban and suburban Canada goose populations has been growing rapidly since the mid 1980s. A lack of basic understanding about the biology and ecology of locally abundant goose populations has led, in part, to argument between opposing camps over the appropriate approaches and methodologies to resolve human-goose conflicts. Animal welfare interests have focused on the humaneness of roundup and slaughter programs, and advocated non-lethal approaches coupled with what they view as the more benign population control activity of egg addling. Some traditional wildlife managers have argued that non-lethal approaches have been tried and have failed, and that procedures such as addling do not work quickly or effectively. Differences have led to legal confrontations that absorb considerable energy and effort and may make cooperative involvement more difficult. This paper articulates some of the arguments that comprises the basis for the perspective of animal welfarists. It ends with a call for greater cooperation and involvement between all interests concerned with Canada geese.

ANIMAL POPULATION ECOLOGY AND CONTROL FUNDAMENTALS

Expensive, extensive and apparently lethal control measures have been applied against many species of pest vertebrates and invertebrates for decades. In spite of this, few pests have been annihilated, and in many cases the stated goals have become progressively more modest, so that now we speak of saving foliage or a crop, rather than extermination. It is of interest to examine the reasons why animals are so difficult to exterminate, because this matter, of course, has implications for the type of control policy we pursue in the future. Also, it has implications for the problem of evaluating comparatively various resource management strategies. There are many biological mechanisms which could, in principle, enhance the performance of an animal population after control measures have been applied against it. These are of four main types: genetic, physiological, populationa1, and environmental. We are all familiar with the fact that in applying a control measure, we are, from the pest's point of view, applying intense selection pressure in favor of those individuals that may be preadapted to withstand the type of control being used. The well-known book by Brown (1958) documents, for invertebrates, a tremendous number of such cases. Presumably, vertebrates can show the same responses. Not quite so familiar is the evidence that sub-lethal doses of a lethal chemical may have a physiologically stimulating effect on population performance of the few individuals that happen to survive (Kuenen, 1958). With further research, we may find that this phenomenon occurs throughout the animal kingdom. Still less widely recognized is the fact that pest control elicits a populational homeostatic mechanism, as well as genetic and physiological homeostatic mechanisms. Many ecologists, such as Odum and Allee (1950, Slobodkin (1955), Klomp (1962) and the present author (1961, 1963) have pointed out that the curve for generation survival, or the curve for trend index as a function of last generations density is of great importance in population dynamics.