More eagles in Pennsylvania are dying from lead contamination.
Granted, there are more eagles in the state than there has been for quite some time, so it makes sense that an increase in mortality would result from numerous factors, including lead.
But what I find alarming is the amount of lead in of some of the eagles that have perished recently, particularly in the northeast.
Pennsylvania Game Commission biologist Kevin Wenner, who oversees the northeast region, told me he submitted four dead eagles for testing this year. One died from trauma, results have yet to come in for another — and the other two eagles succumbed to lead poisoning, or intoxication.
Wenner cautioned that the two eagles were found dead, so lead can’t be ruled as the sole cause of death but at the very least it’s a contributing factor.
But one of those eagles, which Wenner submitted for testing on Sept. 19, had a lead level of 41 parts per million.
Last year there were two eagles in the region that were found dead with elevated lead levels. A golden eagle in Sullivan County was observed having difficulty flying and the next day it was dead. Test results indicated a lead level of 36 ppm. And a bald eagle in Pike County last year was found dead — it had a lead level of 27 ppm.
Wenner said a level greater than 6-8 ppm is considered as lead intoxication for eagles, and the aforementioned raptors had concentration three to five times higher.
So how are eagles ingesting all of this lead? Where is it coming from?
Wenner said a source is often hard to determine. Unless a wildlife rehabilitator recovers something that a bird excretes, it’s impossible to tell what was ingested that caused lead levels to skyrocket.
But it’s no secret how lead can enter the food chain.
The malleable metal is often used in fishing sinkers, shot and bullets. Lead remains behind when an angler snaps a snagged line, wounded game isn’t recovered or even from fragments existing in the gut pile from a deer.
I think the latter is a big contributor to lead poisoning in eagles, as they are a known scavenger and a gut pile in the winter makes for an easy meal.
According to a Game Commission press release, lead fragments can be found as far as 18 inches away from a bullet’s point of impact. If you shoot a deer in the front shoulder, for example, fragments can end up in the entrails.
Consider that the two eagles that died last year with elevated lead levels were found in February, and it’s certainly feasible that they could have fed on gut piles remaining in the woods from the late deer seasons.
While hunters aren’t intentionally, or even knowingly for that matter, leaving lead-laden gut piles in the woods for eagles to ingest, there is something we can do.
Wenner recommended burying a gut pile or, if that isn’t an option, cover it with leaves and branches so it’s not visible to eagles from the air.
It makes sense, but I have to wonder: if gut piles are a source of lead for eagles, why aren’t other scavengers, like coyotes, succumbing to lead intoxication?
Game Commission Wildlife Veterinarian Justin Brown said mammals appear to be more resistant to lead toxicity. Raptors, however, are particularly vulnerable because the acidic nature of their stomach causes rapid absorption of any ingested lead, he added.
So, the increased availability of gut piles during and after deer season coupled with the eagle’s penchant to scavenge for a meal, and the acidic nature of its stomach, creates a deadly situation for our nation’s symbol.
Does it mean it’s time to ban lead fishing sinkers, shot and bullets?
I think that’s a bit premature. But if the instances of eagles with elevated lead levels continues to increase, it’s something that I’m willing to consider.
After all, hunters and anglers are conservationists first. We should be concerned about all species — not just the ones we pursue.
Reach Tom Venesky at 570-991-6395 or on Twitter @TomVenesky