By Marcia Anderson
(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.
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: firstname.lastname@example.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.