Stan,
Bald eagles are well known to have different digestive physiology than just about any other avian predator. They have unusually high acid content in the digestive tract, the theory is it developed in response to the eagles penchant for eating carion, when available, as a way to protect the birds gut while consuming spoiled meat. Owls seem to be almost impervious to lead poisoning, by way of comparison.
It makes Bald Eagles more sensitive to lead in the environment.
THAT SAID, nobody has been able to demonstrate that using lead ammunition has hurt eagle populations in the last 50 years.
I'm all for good science, and not knee jerk regulation.
Best,
Ted
In the last 50 years, there's been a veritable explosion in the eagle population: From only a few hundred breeding pairs to the current five figure level. Unfortunately, although we usually focus on wildlife as a species, the bald eagle is a separate case. Highly visible, our national symbol. And obviously, because there are so many more of them these days--in places where they hadn't been seen in a very long time--more sick birds will be found.
It would seem that woodcock also have a high tolerance for lead. Studies have shown that the lead in their systems far exceeds the level that would be fatal to waterfowl. Of course in the case of woodcock, it's particularly difficult to determine the source of the lead, given what and how they eat. If there's lead in the soil, since they probe for worms, it's quite likely they'll ingest lead. Analyzing the lead, researchers note that it COULD come from lead shot. But none of the birds examined in the study in question had any lead pellets in their digestive systems.
