MISSOULA, Mont. (AP) -- A Pennsylvania man pleaded guilty to a federal wildlife charge Tuesday and agreed to testify in this week's trial of a co-defendant described by Montana game wardens as a ''serial poacher."

Nicola Alfeo, 40, was scheduled for trial Thursday along with Dean E. Ruth of Seeley Lake and Ruth's nephew, Gale M. Ruth Jr. of Pennsylvania.

Instead, Alfeo pleaded guilty to a misdemeanor -- transporting illegally taken animals -- that carries up to one year in prison and a $100,000 fine. U.S. District Judge Donald Molloy agreed to sentence Alfeo after he testifies in the Ruths' trial.

Alfeo told the court he shot a male antelope and male deer in October 1998 near Seeley Lake and took them to Pennsylvania. Alfeo also said he paid Dean Ruth's brother, Gale M. Ruth Sr., $500 for Montana hunting tags. He later traveled to Seeley Lake with Gale M. Ruth Jr. where he shot the animals.

Alfeo said he also paid $500 to Dean Ruth for lodging and $1,000 for the hunt. He said he did not have a hunting license, never saw the hunting tags and didn't look at the tags Dean Ruth put on the animals.

Dean Ruth, Gale Ruth Jr. and Alfeo were arraigned in May on conspiracy and violations of the Lacey Act. The three charges carry maximum penalties of five years in prison, a $250,000 fine and three years of supervised release.

In December, Dean Ruth, 36, and his wife Renita were charged in state court with a combined 43 poaching-related charges. The Ruths pleaded not guilty in March.

They surrendered to state wildlife authorities in January after an extensive search that extended to Pennsylvania, where the couple lived before moving to Montana about three years ago.

Some of the investigation centered on property the Ruth family still owns southeast of Erie. Game officials have said the Ruth family has a history of game violations dating back 50 years in Pennsylvania.

Authorities said the charges against the Ruths involve more than 100 ''trophy-class" game animals -- including moose, bear, mountain lions, elk, white-tailed and mule deer -- that were killed in Montana over an eight- or nine-year period.

In April, Dean Ruth and two other men were convicted of killing a bear out of season in Pennsylvania. He was fined $800 and charged $2,500 in restitution.