John Slutsky, the owner of La Luna Dairy in Wellington, knows all too well how problematic flocks of starlings can be around large amounts of cattle feed.
“For the young calves, it was the worst,” said Slutsky, who tried poisoning, shooting and scaring the birds away for years in conjunction with the USDA’s Colorado Wildlife Services without success. “Some of them would be literally covered with (bird guano).”
This year, Slutsky said that his dairy has been remarkably starling free, though he questioned whether that could be because of the successful poisoning at Horton Feedlot, roughly 11 miles away as the European starling flies. He does know that it’s not because of any actions that he has taken at the dairy.
“I can say for a fact that we have never poisoned a starling,” Slutsky said. “We tried, but they (Wildlife Services) were never able to get the birds to go to the poisoned grain.”
While Wildlife Services is routinely under fire for its more controversial programs — especially regarding the killing of predator species, such as wolves, coyotes and mountain lions — its projects concerning bird-damage management tend to generate a lot less press. That is partially true because the service tends to lump all such measures together, whether it’s scaring flocks of birds away from airports or poisoning hundreds of thousands of birds to protect agricultural interests.
At least that’s how the Colorado Wildlife Services proceeded through its own environmental assessment concerning bird-damage management, a 208-page document that was adopted in January 2013. The use of the DRC-1339 poison is only a small part of the document, which essentially certifies that all the Wildlife Service’s bird management activities are environmentally compliant across the state. DRC-1339 is only available to Wildlife Service personnel, but avian toxicants available to private individuals include Avitrol and Starlicide Complete, both of which contain formulated DRC-1339.
Regarding the use of DRC-1339, the document essentially mirrors comments made by Wildlife Services employees regarding the recent poisonings, which is not surprising since one of the assessment’s chief authors was Mike Yeary, Director of USDA’s Colorado Wildlife Services. What is more surprising, however, is that the authors made no note of the public discomfort with the poisoning of large flocks of birds and little or no note of recent studies regarding the use of DRC-1339.
“DRC-1339 is one of the most extensively researched and evaluated pesticides ever developed in the field of wildlife management,” states the EA, citing a 1997 USDA study. “Over 30 years of studies have demonstrated the safety and efficacy of this compound.
“Secondary poisoning has not been observed with DRC-1339 treated baits,” the EA states, referencing a 1979 study. “This can be attributed to relatively low toxicity to species that might scavenge on birds killed by DRC-1339 and its tendency to be almost completely metabolized in target birds leaving little residue for scavengers to ingest. Secondary hazards of DRC-1339 are almost non-existent.”
But in writing the environmental assessment, Wildlife Services did not mention growing concerns about the susceptibility of both bird and mammal populations experiencing secondary poisoning, including magpies, raptors (especially owls) and some small mammal populations (especially cats). This secondary poisoning could occur through direct consumption of poisoned substances, such as a cat eating an undigested kernel of poisoned corn in the digestive tract of a starling, or through chronic consumption of the flesh of poisoned birds for a prolonged period of time.
Much of the emerging information was chronicled in the USDA’s own 2003 report, “Acute and Chronic Toxicity of Compound DRC-1339,” authored by three researchers at the USDA’s National Wildlife Research Center in Fort Collins. Cited as a source in the 2013 environmental assessment, the 2003 report does reflect how efficient DRC-1339 is in targeting mostly starlings and other birds blamed for agricultural damage. But the 2003 report doesn’t mirror the 2013 environmental assessment or the statements made by Wildlife Service employees.
“The biochemical mechanism behind the toxic action of DRC-1339 and the ultimate cause of death are not clearly understood for any species of animal,” the 2003 study states. The study goes on to say that once ingested by animals, the avicide is “rapidly hydrolyzed to 3-chloro-p-toluidine (CPT), which is believed to be the toxic compound” in the DRC-1339. The CPT is believed to cause necrosis of the the kidney, but “in less sensitive species, the mode of action of CPT is believed to be depression of the central nervous system, resulting in cardiac or respiratory arrest,” the report said.
Another key feature of the starling-poisoning program is that selective targeting of destructive birds is done at the field level. Essentially, field technicians find the best location and time that the maximum number of starlings can be poisoned, while limiting the exposure to other birds and animals.
Wildlife Services information indicates this targeting is almost a 100 percent proposition, but that wasn’t the case when Slutsky brought in the service to poison birds at La Luna Dairy. Slutsky said that service personnel were never able to get a single starling to their proposed bait site, mostly because of the abundance of grain at locations the starlings were already using.
Slutsky said the starlings were more than a nuisance; the threat of contamination and the spread of diseases such as salmonella were constant areas of concern while the starlings flocked at his dairy. Essentially, the dairy tried almost every method at its disposal to get rid of the starlings, including boom boxes blasting bird distress calls and huge inflatable owls.
This year, the flocks have just vanished, which may or may not be due to successful poisonings at the Horton feedlot.
“This year has been great, in not having to deal with the starlings,” Slutsky said. “But there are still the pigeons.”
And for most of Wildlife Services’ poisoning efforts, the public will never know exactly how the poisoning is conducted, because the Service has shielded its clients from all disclosure. In fact, in the case of the Horton Feedlot poisoning, they insisted that their clients were protected from this disclosure even though the poisonings in five states were part of a publicly-funded study.
The North Forty News in November submitted a Freedom of Information Act request to the U.S. Department of Agriculture for locations of mass bird poisonings in Colorado administered by Wildlife Services. Although the USDA acknowledged the request, it has not yet responded with the information.