On 3/10/2016, the Minnesota Department of Natural Resources (MN DNR) held a public forum on a "possible requirement that only non-toxic shot be used on wildlife management areas in Minnesota's farmland zone." This was a follow-up to a request for public comments in October 2015.
In the news:
Supporters of proposal at the 3/10/2016 forum included hunters, conservation organizations, and wildlife-rehabilitators.
The main opposing argument from the Safari Club representative (and several testifiers repeating it) was that no significant population-level impact has been proven. In other words, the numbers of raptors (and other predators and scavengers) that have been brought into wildlife-rehabilitation centers with lead poisoning over the years has been lower than the numbers killed by collisions with vehicles, power lines, and window glass.
Remember that the known number of cases of lead poisoning is certain to be lower than the actual number. That there's an easy solution: switch to non-toxic ammunition. Take a look at the price chart posted at the back of the room--toxic vs. non-toxic at each level of ammunition--small differences in price. Steel is cheaper than lead: as more people switch to non-toxic ammunition it will become cheaper than toxic ammunition. Almost any shotgun with a modular choke can be fitted for non-toxic shot. Non-toxic shot--weighing less than lead shot, but therefore fired at higher velocities--is highly effective for hunting.
Yet, what the Safari Club representative wanted to talk about was what we don't know about how the deaths of wildlife from lead poisoning, and what we do know about their deaths in collisions with vehicles, power lines, and window glass.
In other words, the real reason wasn't mentioned. The real reason is "we don't like you telling us what to do."
MN DNR presentation on the proposed non-toxic shot rule.