SULLIVAN — A bald eagle found in Sullivan with lead poisoning died overnight Jan. 13.
Maine game warden Chris Roy responded to a Jan. 6 report of the eagle found lying on the ice on Flanders Pond, said Diane Winn, co-founder and executive director of Avian Haven, a bird rehabilitation center in Freedom. Roy took the sick eagle to Ellsworth, from which a chain of Avian Haven volunteers transported it to the sanctuary.
The Sullivan eagle was one of five in Maine that were found with lead poisoning during the first two weeks of the new year.
“Only one of the five eagles admitted so far in 2020 with elevated blood lead levels is still alive, and we do not have high hopes for that remaining one,” Winn said early Jan. 14.
An eagle found in Thorndike Jan. 1 died the same day. An eagle found Jan. 9 in North Chester died the following day. Another, found Jan. 12 in Peru, died Jan. 13. The remaining eagle, which was still alive as of Tuesday, was found Jan. 2 in Thorndike.
Eagles are “opportunistic predators,” says the website of the National Eagle Center in Wabasha, Minn. In addition to hunting live prey, they are scavengers that will feed on carrion.
Lead poisoning occurs when the eagle eats carrion killed by hunters using lead ammunition. This can include game used as bait for other animals as well as gut piles left behind in the field. The connection is well documented by studies, Winn said.
“Many hunters are still unaware of the danger of leaving game meat that has been shot with lead in the field where eagles can get to it,” she said. “It only takes a tiny fragment of lead to debilitate or kill a bald eagle.”
One No. 6 shot contains enough lead to kill three to five eagles, according to literature provided by Avian Haven.
Even humans can be poisoned by eating game meat shot with lead ammunition, which breaks up into tiny fragments upon impact with the animal.
Winn said it is unusual to find five eagles with lead poisoning in the span of only two weeks, but she expects to see more before the winter is over. Typically, Avian Haven admits a dozen eagles per year that have elevated levels of lead in their blood. The majority of cases occur from October through April, when eagles are feeding on game remains rather than fresh fish.
About two-thirds of the adult eagles admitted to Avian Haven over the past several years have been exposed to lead. Whether the exposure results in death depends on the levels. But, even lower levels of exposure are problematic.
“Lower blood lead levels are not fatal but affect body systems in such a way as to impair coordination, increasing the likelihood of sustaining injuries, many of which cannot be repaired,” Winn said.
In general, raptors are much more sensitive to lead than mammals and eagles are among the most sensitive of the raptors.
Anyone who finds an eagle that is obviously injured or is acting strangely can call the Warden Service or a rehabilitator such as Avian Haven.
“Our admission exam for all eagles includes both X-rays and measurement of blood lead levels,” Winn said. If X-rays reveal the presence of lead fragments in the bird’s digestive tract, Avian Haven removes them with a stomach flush. Blood lead levels also can be reduced with treatment.
“But, by the time we get the bird, irreparable damage to organ systems may well have already been done,” she said.
Winn would like to see the state require the proper disposal of the potentially toxic remains of game killed with lead ammunition, including carcasses, gut piles and waste meat from game butchers.
“If this meat could be kept out of the field, the problem for eagles would pretty much disappear,” she said. “Hunters can also, of course, voluntarily choose non-lead ammo, both bullets and shot pellets.”
Lead is also used in fishing gear, but Avian Haven has never admitted an eagle with a lead fishing lure in its system. Loons can get lead poisoning from ingesting lead fishing sinkers and Winn encourages fishermen to use sinkers made of other materials.
Anyone who wishes to dispose of lead safely can take it to a site that takes old lead fishing sinkers. A list can be found at https://fishleadfree.org/me/.