Still poison: Lead bullets remain a big problem for birds

You may have noticed a rare of show of Congressional compromise recently, when members from both sides of the aisle jumped at the chance to sponsor and vote for the Bipartisan Sportsmen’s Act of 2014. The bill would have done a number of things, but two stood out: it would have exempted lead hunting ammunition and fishing tackle from longstanding regulations, and it would have allowed federal lands (like, say, in National Parks) to be leased for the construction and operation of shooting ranges. Mix that with some new research by the US Geological Survey, Fish and Wildlife Service, and others, and you’ve got very bad news for birds.

Now, we’ve known about lead’s toxic effects in humans and every other creature for a long time. Because of its toxicity, regulations in the US have been in place for decades now limiting lead’s use in hunting certain birds (waterfowl in particular). Even still, there were hints that lead exposure from bullets is still a major issue, so researchers set out to review and characterize what we know about this. Their conclusion: “The cumulative body of scientific evidence unequivocally suggests that Pb exposure from ammunition and fishing tackle is directly responsible for numerous bird deaths each year.” They noted certain species in particular; the endangered California condor, for one, is at serious risk thanks to lead accumulating in its environment.

eaglesleadThe image above shows how lead bullets fragment on impact, which can scatter either into an animal it hits or simply into the ground around a shooting range. Copper bullets, an easy alternative to lead, do not shatter as lead does. Lead can build up in birds from direct exposure, meaning when birds mistake lead pellets for food and ingest it, or when birds eat an animal that has the lead shot in it. To the right is a golden eagle chick in a nest ready to enjoy a meal of Belding’s ground squirrels; below are x-rays showing that very type of squirrel riddled with lead fragments.

So obviously, exempting ammunition makers from lead regulations seems a poor idea if it is already a widespread problem in birds. But mix that with the shooting range provision and it gets even worse. Back to the new paper: “The highest human-caused Pb concentrations associated with ammunition are found in and near shooting ranges… many grit-seeking birds pick up Pb fragments at or near shooting ranges.”

So, let all hunting ammunition be made with lead, and let people start building shooting ranges in places where, generally, your average bird wouldn’t come into as much contact with lead bullets. Sounds good all around.

Luckily for the birds, this bill died in a procedural vote in the Senate, but the bipartisan support suggests it could reappear in some form or other in the future. It only fell in the Senate because some heavily pro-gun folks tried to include amendments outside of the “sportsmen” genre, like loosening gun restrictions in the District of Columbia. There doesn’t seem to have been much argument over bird conservation, though clearly the weight of evidence suggests there should be.  – Dave Levitan | July 15 2014

Source: Haig SM, D’Elia J, Eagles-Smith C, et al (2014). The persistent problem of lead poisoning in birds from ammunition and fishing tackle, Condor: Ornithological Applications, 116 (3) 408-428. DOI: 10.1650/condor-14-36.1

Images: Haig et al, Condor