Public Health
Those looking to justify the killing of Canada geese turn to the use of scare tactics with remarkable predictability. The strategy involves creating the illusion that Canada geese are a threat to public health. The mere assertion that a "health issue" exists has been an effective way to generate fear about the presence of Canada geese and an artificial urgency about what must be done. Interestingly, among the most outspoken on this issue are individuals who are unqualified to make health risk assessments. Park managers, rangers, hunters, outdoor columnists, wildlife managers, mayors, etc., are suspiciously too willing to offer their epidemiological assessments despite their lack of credentials. The origin of their information can usually be traced to something they were told by one of the other unqualified parties. While less common, there are cases where allegedly qualified individuals (i.e., health commissioners) render false information under political pressure from anti-goose forces.
In most cases, the health scare does not involve the geese per se, but rather, their droppings. The basis of the argument is that Canada geese must be killed because goose droppings contain human pathogens (disease-causing bacteria). As has been pointed out in the literature by Weiner, et al. (Applied and Environmental Microbiology, Aug. 1979, p. 258), and at a public presentation in Rockland County, New York (Sept. 22, 1993), by Dr. Milton Friend, U.S. Fish and Wildlife Service Waterfowl Infectious Disease Specialist, Canada geese are not carriers of microorganisms (pathogens) that significantly threaten public health.
In fact, in New York, the Department of Environmental Conservation (DEC) attempted to strengthen their campaign against geese by testing goose droppings for human pathogens. (It is interesting to note that these tests were carried out after they had already claimed that geese were a " threat." The outcome of their study was never publicized because they were unable to prove their point. They managed to confirm what was already known: Canada geese do not pose a health threat even remotely serious enough to justify their mass destruction. The Coalition has contacted the Centers for Disease Control (CDC) and various state health departments on this matter and these sources have indicated that no human illnesses have been linked to the presence of Canada geese in the suburban setting. Yet, as indicated in a 1991 report from the Town of Greenwich, Conn., none of this is news:
"Examination of goose droppings showed only expected bacteria in normal concentrations (Carolyn Baisley, Director of Environmental Health and Laboratory for the Town of Greenwich, pers. comm.). To date, state pathologists know of no cases where human illness can be ascribed to goose droppings (fide The Northeastern Research Center for Wildlife Diseases, Pathology Department, University of Connecticut). Indeed, only a few diseases can be transmitted to humans from birds. Thus, it appears that the primary concern is the unsightly and unpleasant concentrations of droppings rather than a health risk."
-Management of the Canada Goose in the Town of Greenwich, Conservation Commission position paper, page 4, Greenwich, CT, February, 7, 1991.
After making the health issue the central theme of an anti-goose campaign, and after the slaughter of 251 Canada geese (including several goslings) in Clarkstown, NY, came the admission that the health scare was unfounded (NY Times, 9/9/96 article, "Goose Round-up Flopped, But Mayor is Undaunted").
In this case, the assertion that geese posed a health threat was not only unsupported, but fraudulent; the Rockland County Health Department (a co-conspirator) was in possession of scientific studies showing that Canada geese were NOT carriers of shigella, salmonella or other bacterial pathogens (Applied and Environmental Microbiology, Jan. 1979, p. 14).
More information on Canada geese and public health.
Water Quality
Canada geese have also been accused of causing water pollution in areas where they congregate and are alleged to be "overpopulated." As with the health claims mentioned above, these allegations are also usually without scientific basis and made by individuals without relevant credentials.
One commom claim is that a swimming area had to be closed because of Canada geese. "Elevated coliform counts" is commonly cited, followed by "and the geese are to blame." While it is true that Canada geese contribute fecal material, and therefore coliforms, to natural bodies of water, so do a large number of other species, including mammals and other birds. This is a natural part of the ecology of lakes and ponds, and mechanisms exist to accommodate such infusions. The bacterial content at any given time is dependent on a number of factors, including temperature and the amount of rainfall in a given season. For example, the coliform counts of rivers, ponds and lakes is always elevated after rainfall as organisms (bacteria) in fecal material runs off the land into the water (non-point source pollution).
When geese are blamed for high coliform counts the accusation is generally based on circumstantial evidence. In most cases, those who target geese as being major coliform contributors have no way of knowing the origin of the coliforms measured (e.g., other wildlife, leaky septic systems, runoff, agricultural sources, etc). Coliform counts simply do not provide this type of information. Furthermore, separating the fecal contributions from all possible sources is not a trivial matter (Applied and Environmental Microbiology, Aug. 1979, p. 258) and therefore rarely carried out. In other words, most coliform count-based accusations regarding the bacterial impact of Canada geese on water quality are fundamentally misleading. However, having said all this, it turns out that the issue of coliforms is actually moot. Even if geese WERE found to be responsible for high coliform counts, there would still be no grounds to take action against them because fecal coliforms themselves are not disease causing and therefore no human health risk can be said to exist!
Why measure coliforms at all? The fecal coliform count is a very simple and inexpensive way to indirectly measure the amount of fecal material present in a body of water (coliforms are a class of plentiful organisms found in the intestinal tract of all animals). It is critical to note that this method determines health risk by implication not direct measure. The underlying assumption in applying the coliform water test is that coliforms are often accompanied by harmful bacteria; this assumption is not always correct. In the case of Canada geese, the assumption is incorrect. In fact, if it is found that geese are the primary cause of high coliform counts, this is good news for humans because studies have shown that the fecal matter of Canada geese rarely contains human disease causing bacteria. On the other hand, if high fecal counts are due to human waste, a major health threat exists since it is common for human excrement to contain pathogens that seriously affect humans.
Slandering geese as a "health threat" based on coliform counts is a common form of deception that is without scientific basis. In the rare cases where more elaborate methods have been used to determine the bacterial impact of Canada geese, it has been found that the presence of geese did not give rise to a health hazard (Johnston and Mounlin, "Microbial Impact to Public Drinking Water Supplies by Nonmigratory Canada Geese", Boston University/Harvard Medical School under Permit from the Mass. Division of Fisheries and Wildlife, 12/31/87).
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