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Employee Input Dooms Proposed Canada Geese Study

By Eddy Ball
June 2007

Chris DePerno
Chris DePerno, left, fielded questions as Julius Thigpen looked on. (Photo courtesy of Steve McCaw)

Colleen Anna
Several attendees, such as Biologist Colleen Anna (pictured here), were skeptical about the need for and safety of the NCSU project. Biologist Maggie Humble, who deals with resident geese at her Durham home, questioned the effect of the repellent on other birds. "What will it do to the cardinals?" she asked. (Photo courtesy of Steve McCaw)

Chris Ayers
Chris Ayers described how he would measure geese response to repellent-laced grass. The study also planned to quantify the effects of repellent and mowing patterns on feeding, as well as look at fecal mass, seed germination ability, pathogen content, and nitrogen and phosphorus content. (Photo courtesy of Steve McCaw)

Comments by employees have convinced NIEHS management to turn down a Canada Geese study on campus proposed by North Carolina State University (NCSU) Fisheries and Wildlife Sciences researchers. The comments, presented to NIEHS Associate Director for Management Marc Hollander, were in response to an information session about the proposed study presented by Professor Christopher S. DePerno, Ph.D., and Graduate Student Chris Ayers on April 26 in Rodbell Auditorium.

In addition to studying the behavior of Canada Geese, DePerno and Ayers proposed testing the efficacy of the Environmental Protection Agency (EPA)-approved repellent Flight Control Plus®. They were seeking to include the NIEHS campus as one of six study sites in the Triangle where researchers would apply the repellent to the birds' food source and study the effects of different mowing schedules on feeding patterns.

DePerno opened the session with a familiar tale of an environmental success story soured by the unanticipated overpopulation of a species once endangered by "unrestricted harvest." Today an estimated 600,000 resident, non-migrating Canada Geese thrive along the east coast of the United States. As a result of what DePerno called a "management success," in some places the population and its impact on humans increase by ten percent each year.

One resident goose can defecate up to 30 times a day, leaving behind one to two pounds of feces for the average three to four pounds of grass it eats every 24 hours.

The waste, which can contain zoonotic pathogens and parasites, such as Giardia, creates a potential health concern wherever children play. The fertilizer-rich feces can also contaminate waterways and turn walkways into safety hazards.

The animals are aggressive in defense of their young and willingly take on humans perceived as threatening their nests - whether on suburban lawns, athletic fields and golf courses or at offices, parks and institutions. When geese find a friendly habitat, such as the many lawns, ponds and lakes in the Triangle, they tend to abandon their annual migrations. As non-migratory birds, they can live as long as 25 years. With each couple producing 5 to 12 eggs each year, the problem can only worsen over time.

DePerno and Ayers represented the repellent as species-specific, humane, safe and non-toxic - and far more effective than dogs, fencing or alarming noises for deterring the geese. They also maintained that the study's goal is to get much needed information about the geese and not necessarily to support a specific strategy for dealing with the unwanted visitors. "These wildlife issues can be very contentious, but we're researchers," DePerno explained. "I'm neither for geese nor against them."

Meeting facilitator Microbiologist Julius Thigpen, Ph.D., joined DePerno in the question and answer portion of the session. Several people in the audience wanted to know more about the possible effects of consumption of the repellent by children and pets. National Toxicology Program (NTP) Investigator David Malarkey, D.V.M., Ph.D., noted that "the geese are not really a problem on our campus." Malarkey also questioned whether the active ingredient of the repellent, 9,10-anthraquinone, is really as safe as the manufacturer claimed. He added that NTP studies of the compound had found evidence of its carcinogenic potential.

"I decided against the study based on the comments I received," Hollander said after rejecting the proposal. He described the information session as part of a strategy to increase stakeholder participation in decision making that includes reviving the Environmental Awareness Advisory Committee.

9,10-anthraquinone - A Tale of Two Agencies

Arkion Life Sciences and distributor SePRO Corporation( Exit NIEHS describe Flight Control Plus® as an "effective and humane (non-lethal) Canada Goose repellent." The repellent works by causing "temporary but very effective digestive irritation" in geese. Because it leaves a distinctive "Visual Warning" that the birds recognize when viewed in the ultraviolet light spectrum, geese soon associate the sight of treated grass with the digestive irritation and have no choice but to seek an alternative food source. SePro claims that the repellent won't wash or rub off treated grass, making it persistent and safe for humans.

In December 1998, the EPA issued its Fact Sheet( Exit NIEHS in response to a request for approval for non-food use as a repellent for the product Flight Control Plus® from Environmental Biocontrol, International. Based on studies submitted by the company, EPA found no reason for concern regarding occupational, school and day care exposures. "The information submitted in support of the application for registration of anthraquinone," the agency concluded, "adequately satisfies the requirements set forth in 40 CFR 158.690 (c) for biochemical pesticides for nonfood outdoor uses. The overall toxicological risk from human exposure to anthraquinone is considered negligible."

In 2004, however, NTP toxicity testing on rodents told another story in a report by scientists at the Batelle Columbus Laboratory. NTP Technical Report 494( raised concerns about clear evidence of liver carcinogencity in rodents consuming dosed feed containing the compound. The report also found non-neoplastic lesions in other organs and suspected involvement in the endocrine system.

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