Hunting does not only kill the animal standing in front of the gun. A bullet enters a deer, moose or elk. The animal dies. Their body is cut apart. Organs and other remains are abandoned where they fell. Then someone else arrives for dinner. Eagles. Bears. Wolves. Coyotes. Ravens. Wolverines. And if that bullet contained lead, the hunter may have left poison behind for them too.
New research examining big-game hunting across Canada and the northern United States has calculated the extraordinary amount of lead potentially being scattered through ecosystems every hunting season. During 2023–2024, hunters killed 383,402 big-game animals in Canada and another 1,711,508 across 12 US states bordering Canada. The researchers estimate that hundreds of kilograms of bullet-derived lead could consequently be left available to scavengers every year. And we are not talking about intact bullets sitting harmlessly inside bodies. Lead hunting bullets fragment on impact. Hundreds of visible fragments can spread as far as 45 centimetres from the wound channel, while microscopic fragments can number in the thousands. Once swallowed and dissolved in the digestive system, that lead can be absorbed into the body.
Hundreds Of Kilograms Of Lead
Researchers modelled 3 commonly used bullet sizes. They estimated that one .264-calibre bullet could leave 0.78 grams of lead in discarded organs. A .300-calibre bullet could leave 0.84 grams, while a .338-calibre bullet could leave 1.35 grams. Those figures assume 30% of the lead lost by the bullet ends up in the organs left behind.
Scale that across an entire hunting season. Using .300-calibre bullets, the model estimated about 340 kilograms of lead deposited across Canada and another 1,442 kilograms across the 12 neighbouring US states. And that is based largely on the conservative assumption of one bullet per animal.
The researchers also calculated a two-bullet scenario, which they describe as more realistic. Unsurprisingly, the amount of lead doubles. Even if half of hunters switched to ammunition without lead, the same model suggests around 891 kilograms could still be deposited across Canada and those US states in a single season.
Eagles Fly Straight Through The Danger
For golden eagles, geography makes this particularly grim. Two major migration routes pass through regions where huge numbers of animals are shot. One runs through eastern Canada into Maine, Vermont and New York. Another stretches from Alaska through western Canada into Washington and Montana.
Along those routes, migrating eagles can encounter the remains of hundreds of thousands of hunted animals. And lead exposure in eagles is hardly theoretical.
One analysis cited in the research found evidence of previous lead exposure in 99.3% of bald eagles and 94.1% of golden eagles examined across the US. Lead bullet fragments were found in the digestive tracts of 14.2% of bald eagles and 11.8% of golden eagles.
In Canada, 10% of bald eagle deaths examined between 1991 and 2016 in Nova Scotia, New Brunswick and Prince Edward Island were caused by ingestion of lead bullet fragments. Nearly 3 quarters of the dead birds showed evidence of previous lead exposure.
One animal is shot. Another animal eats what the hunter leaves behind.
Another dies.
Bears Are Being Exposed Too
Bears face a different problem.
A large bear may be capable of eating an entire pile of discarded organs at once. Wolves in a pack may do the same. Eagles eat less during an individual feeding, but their mobility may allow them to find more contaminated remains. Lead exposure can also accumulate. Canadian black bears have already shown evidence of cumulative lead build-up, likely because repeated exposure adds to lead stored in their bodies over time. And the true scale is uncertain. Animals shot but never retrieved are missing from official kill totals. One US study cited by the researchers estimated that around 20% of shot elk were not recovered. Small mammals such as prairie dogs and ground squirrels are also excluded from the big-game figures, despite being shot with fragmenting ammunition and often left whole for scavengers to eat.
There are uncertainties in the other direction too. Some animals are killed with bows rather than rifles, and some hunters already use ammunition without lead. The researchers therefore make clear that their numbers are estimates, not a precise national lead count. But the basic problem does not require guesswork. Hunters shoot animals with bullets that fragment. Lead enters abandoned body parts. Scavengers eat those remains. Lead poisoning follows. And unlike many environmental hazards, this one has an obvious solution.
Stop using lead ammunition.
If you care about animal WELFARE.
Don’t shoot ANYBODY.
If you care about animal RIGHTS.
Not to mention the babies who might be left without their moms