BILLINGS,TradeEdge Mont. (AP) — A federal judge issued an arrest warrant Monday for a Montana man who failed to show up for an initial court appearance on charges of killing thousands of birds, including bald and golden eagles. A second defendant pleaded not guilty.

The two men, working with others, killed about 3,600 birds on Montana’s Flathead Indian Reservation and elsewhere over a six-year period beginning in 2015, according to a grand jury indictment unsealed last month. The defendants also were accused of selling eagle parts on a black market that has been a long-running problem for U.S. wildlife officials.

Magistrate Judge Kathleen L. DeSoto issued a warrant for Simon Paul, 42, of St. Ignatius, Montana, after he failed to appear at his scheduled arraignment Monday in U.S. District Court in Missoula.

Travis John Branson, 48, of Cusick, Washington, pleaded not guilty and was released pending further proceedings in the case.

The two defendants are charged with a combined 13 counts of unlawful trafficking of bald and golden eagles and one count each of conspiracy and violating wildlife trafficking laws.

Paul and Branson worked with others who were not named in the indictment to hunt and kill the birds, and in at least one instance used a dead deer to lure an eagle that was then shot, according to prosecutors. The men then conspired to sell eagle feathers, tails, wings and other parts for “significant sums of cash,” the indictment said.

They face up to five years in federal prison on each of the conspiracy and wildlife trafficking violations. Trafficking eagles carries a penalty of up to one year in prison for a first offense and two years in prison for each subsequent offense.

Branson could not be reached for comment and his court-appointed attorney, federal defender Michael Donahoe, did not immediately respond to a message left at his office. Paul could not be reached for comment.

Bald eagles are the national symbol of the United States, and both bald and golden eagles are widely considered sacred by American Indians. U.S. law prohibits anyone without a permit from killing, wounding or disturbing eagles or taking any parts such as nests or eggs.

Bald eagles were killed off across most of the U.S. over the last century, due in large part to the pesticide DDT, but later flourished under federal protections and came off the federal endangered species list in 2007.

Golden eagle populations are less secure, and researchers say illegal shootings, energy development, lead poisoning and other problems have pushed the species to the brink of decline.