Numerous studies have been finding a positive correlation with big-game hunting season and incidences of raptors (eagles, vultures, condors, hawks) with lead poisoning. The use of lead ammunition, and scavengers feeding on the remains from a hunters kill is the main source of the problem. Lead ammunition tends to fragment into tiny pieces throughout the tissue upon impact. Hunters generally only take home the meat they wish to consume and leave the remains for other animals. Scavengers which consume the carrion will ingest small pieces of lead ammunition, which leads to increased blood lead levels. Some symptoms from increased lead toxicity include  being lethargic, weakness, inability to fly, impaired vision, seizures, and death. A study conducted in Jackson Hole, WY, showed that switching to copper ammunition over the course of two hunting seasons resulted in a reduction of cases of Bald Eagles with lead poisoning. This is likely due to that copper ammunition doesn't fragment the way lead ammunition does, and 80-100% of the bullet can be retrieved compared to 20-30% for lead ammunition. 
        This film is not meant to be an attack on the hunting community. Due to the increased fragmentation of forests and certain animals like white-tailed deer, which have flourished in many regions, hunting plays an important role in biological control. Hunting organizations are also responsible for some of the largest contributions to conservation efforts. The idea with this film is to shed light to the issue, and encourage the use of non-lead ammunition.