bird poisoning

An Annual Recurrence of Avian Chlordane Poisoning in one NJ Town

By Marcia Anderson

Cooper's Hawk

Cooper’s Hawk

(Part two of a series on chlordane poisonings)

Residents reported finding dead starlings, grackles and robins in Scotch Plains, New Jersey, as long ago as July 1977; and, more recently, in July of 1996, New Jersey Fish &Wildlife (F&W) investigated a report of a large number of these dead birds. During an inspection of the area, 75 birds, including 18 grackles and six starlings were recovered from one property adjacent to a local golf course and dead birds were visible on adjacent lawns and streets. The following year, over a three-week period in July, F&W visited a residential area adjacent to a local golf course and recovered a total of 425 dead or sick birds including 307 grackles, 104 starlings and 14 American robins. Thirty-five more debilitated birds were captured alive. Many of these birds were uncoordinated, sometimes flying into stationary objects, while others were seen falling from trees or falling to the ground in midflight

Although birds can fly great distances, sick and debilitated birds seek the comfort of their homes, or roosts, and do not travel far from them, so F&W knew that the source of the poison was nearby. Chlordane poisoning was diagnosed as the primary cause of death in all of the 1997 birds analyzed. In a published paper, F&W believed this to be the largest avian chlordane poisoning incident reported in the United States.

Just last July (2012), confirmed chlordane poisonings occurred in Summit,(approximately eight km from Scotch Plains), Parsippany, Maplewood, and Gibbsboro, N.J.; and on Western Long Island.

Raptor Poisonings

Confirmed and documented cases of lethal chlordane poisoning were found in nine Cooper’s hawks and other raptors. Raptors are secondarily poisoned by consuming contaminated songbirds. Approximately 80 percent of the prey taken by Coopers hawks in the eastern U.S. is avian; so the consumption of chlordane-contaminated birds is the most probable cause of most Cooper’s hawks poisoning cases. The incidence of chlordane poisonings in all raptors, including Cooper’s hawks, peaked in July, coinciding with the peak period of chlordane poisoning of songbirds from eating chlordane-contaminated beetles and grubs.  Poisonings of Cooper’s hawks are of particular concern, because this species is listed as endangered by the state of New Jersey. 

From 1999-2000, 95 raptors were found dead throughout N.J., and were submitted for examination as part of the Fish &Wildlife’s West Nile Virus monitoring program. Chlordane poisoning was found to be the major cause of Cooper’s hawks’ mortality. The incidence of chlordane poisoning in other hawks was lower due to differences in feeding habits.

Take Home Message

Many commonly used insect sprays, weed killers and rodenticides are highly toxic to birds.

Don’t be fooled by chemical products as being touted as “organic.” Many environmentally destructive chemicals are organic. Residues of these compounds remain in soils, sediment, and biota levels sufficient to cause death in some bird species. Also be wary of products with the prefix “eco”, “environ”, or allegedly “green.” Always read the product label first for proper use instructions, use restrictions, and environmental effects, for a truer sense of its impact. In many cases there are less dangerous alternatives to chemical pest control and lawn care. For example, grub control could be pursued with biological methods such as the use of Bacillus popilliae (Milky Spore), or nematodes.

Human safety concerns

As long as you or your children do not munch on grubs, beetles, or birds you should be fine. Make sure your pets do not eat dead or debilitated birds. Wash your hands thoroughly after digging in the garden and before touching food. If you find a sick or injured bird in New York City contact the Wild Bird Foundation: www.wildbirdfund.org. In New Jersey contact the Raptor Trust: info@raptortrust.org .

About the Author: Marcia is the bed bug and vector management specialist for the Pesticides Program in Edison. She has a BS in Biology from Monmouth, second degree in Environmental Design-Landscape Architecture from Rutgers, Masters in Instruction and Curriculum from Kean, and is a PhD in Environmental Management candidate from Montclair – specializing in Integrated Pest Management and Environmental Communications. Prior to EPA, and concurrently, she has been a professor of Earth and Environmental Studies, Geology and Oceanography at Kean University for 14 years.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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30 years after the EPA Ban, Chlordane still Poisons Local Birds

Chlordane

Chlordane

By Marcia Anderson

During a visit to the New Jersey Raptor Trust, a wild bird rehabilitation center, I became aware of recurring and confirmed regional chlordane poisonings in our local bird populations. This prompted my investigation into its cause. Songbirds and raptors in suburban areas of  New Jersey, New York and surrounding states have been found dead and dying of chlordane poisoning every summer, for over 14 years. The gruesome event occurs like clockwork every June and July.

Why? The New Jersey Department of Environmental Protection Fish and Wildlife and the New York State Department of Environmental Conservation tested soils from some local golf courses and found that wildlife poisoning still occurs where there was a substantial effort to control beetle grub populations with organochlorine pesticides for more than 30 years, from the 1950s to the 1980s. This resulted in turf contamination by the very persistent and commonly used organic pollutant (POP) chlordane. While environmental problems have lessened, they have far from disappeared.

 Chlordane Background

Chlordane was introduced in the United States in 1947 as both an insecticide and an herbicide to control lawn, garden, and commercial pests and weeds in turfgrass.  In 1979 restrictions were imposed on the use of chlordane because of its potential human carcinogenicity. It was banned for home, garden and agricultural uses in 1983 – 30 years ago. Chlordane products were allowed for restricted underground termite control for an additional five years until suspended in 1988. The ban of a toxic chemical does not immediately eliminate it from the environment, and chlordane poisoning of birds is still common.

Chlordane is environmentally persistent, and once applied, much of it still remains unaltered in the environment. Residues remain in soils, sediment and biota at levels sufficient to cause death in some bird species. Evaporation is the major route of removal from the top soil layer where chlordane slowly volatilizes into the atmosphere. Sunlight can also break down small amounts of chlordane. Chlordane rapidly binds to clay and soil particles making it highly immobile within soil layers. Chlordane does not chemically degrade and is not subject to biodegradation in soils. Perhaps the only good news is that chlordane has a low potential for groundwater contamination, because it is insoluble in water.

How chlordane is re-exposed:

Many bird mortalities were discovered when the New Jersey Fish &Wildlife Department was testing what they thought was an outbreak of avian West Nile Virus. They discovered that the deaths were attributed to high chlordane concentrations in already resistant insects. Concentrations of chlordane were high in Scarab, June, and Oriental beetles and highest in adult Japanese beetles from suburban area golf courses.

Spring emergence of grubs and adult beetles directly coincides with summer peaks in bird mortality. Songbirds were exposed to chlordane through the ingestion of soil invertebrates, including the aforementioned beetle grubs. In spring, beetle grubs are eaten by grackles, robins, starlings, and crows. By June, emerging adult beetles are eaten by kestrels, blue jays and house sparrows.

The timing of raptor deaths, such as Cooper’s hawk mortalities, coincides closely with the July peak in songbird mortalities, as hawks often feed on smaller songbirds debilitated by the chlordane. Chlordane and its breakdown products are lipophilic, meaning that it bioaccumulates in fatty tissues. Chlordane also affects the nervous system by blocking important chemical signals and enzymes that result in overstimulation and death.

If you find a sick or injured bird in New York City contact the Wild Bird Foundation: www.wildbirdfund.org . In New Jersey contact the Raptor Trust: info@raptortrust.org .

About the Author: Marcia is the bed bug and vector management specialist for the Pesticides Program in Edison. She has a BS in Biology from Monmouth, second degree in Environmental Design-Landscape Architecture from Rutgers, Masters in Instruction and Curriculum from Kean, and is a PhD in Environmental Management candidate from Montclair – specializing in Integrated Pest Management and Environmental Communications. Prior to EPA, and concurrently, she has been a professor of Earth and Environmental Studies, Geology and Oceanography at Kean University for 14 years.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.