For the Birds Radio Program: Trumpeter Swan Lead Poisoning

Original Air Date: Feb. 2, 1989

If we banned lead for waterfowl hunting, why are so many swans still dying of lead poisoning?

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(Recording of a Trumpeter Swan)

Last weekend I went to the annual Minnesota Audubon Council down in St. Paul, where the first order of business was to visit the spanking new Raptor Center. This state-of-the-art facility was just finished last fall, and it’s quite a place. Bald Eagles, Snowy Owls, and Peregrine Falcons are housed in huge rooms designed perfectly for their needs as well as for human visitors to get wonderful views of these splendid birds of prey. The raptor center treats injured raptors from throughout the nation, from the huge and majestic Bald Eagle to the tiny and cute Saw-whet Owl—and in their two-and-a-half million dollar facility they can now do it in style.

There is also a wildlife clinic that treats mammals and non-raptors on the St. Paul campus, so you seldom see anything at the Raptor center that isn’t a bird of prey—that is, until this winter. Suddenly these hawk and owl experts are finding themselves waist deep in Trumpeter Swans. Several months ago the Minnesota D.N.R. asked them to treat any lead poisoned swans that turn up because they have so much experience in dealing with rare and endangered birds. When the agreement was made, no one dreamed that lead-poisoned swans would ever be too serious of a problem. But because of this year’s drought, the raptor center suddenly finds itself in a worst case scenario, treating over 35 deathly ill Trumpeter Swans.Poisonous lead pellets have been sitting like a time bomb at the bottom of lakes and marshes for decades. Waterfowl, like most birds, need grit for digesting their food, and they frequently ingest these lead pellets while feeding in contaminated sediments. Since Minnesota banned the use of lead shot in waterfowl hunting, the problem seemed likely to eventually go away, but instead, this year’s drought and low water levels exposed shot that had long sat in water too deep for waterfowl feeding. Swallowed pellets are slowly ground up in the gizzard, and the toxic element is released to the bloodstream to cause an agonizing death.

Thanks to a radiograph machine in the new Raptor Center, veterinarians can determine quickly and accurately whether any shot remains in the gizzard, can flush it out, and then radiograph it again to make sure they got it all out. They then treat the poisoned bird with injections of EDTA—an expensive drug that binds chemically with lead to form a harmless molecule which can be excreted by the kidneys. It takes three large injections every day to keep the birds alive until their systems completely get the lead out. Meanwhile, the weakened birds require intravenous fluids and force feeding. Because of the huge expense of EDTA, use of the radiograph, and the labor-intensive treatment, the center estimates that they are spending about $3,000 each for treatment–money which they had understandably not budgeted this year. If you’d like to help this worthy effort, you can make a tax-deductible donation to the Raptor Center at the University of Minnesota, St. Paul Campus, 55108.

Experts have known since the 1950’s that about two million waterfowl die of lead poisoning every year. And Bald Eagles often become poisoned after scavenging on the lead-laden carcasses. Minnesota has banned lead shot for waterfowl hunting here, but even so, lead continues to be added to our wetlands every year, since it’s still perfectly legal in shooting grouse, pheasants, quail, and crows, even if those birds are flying right over a marsh. If this is truly going to become a kinder, gentler nation, we need state and federal legislation to ban this poison once and for all.

(Recording of a Trumpeter Swan)

This is Laura Erickson, and this program has been “For the Birds.”