BANGOR — A federal judge on Wednesday wondered aloud if trappers and hunters were getting the message that the Canada lynx is an endangered species and it’s a federal crime to kill it, move or possess its carcass or own its pelt.

“I don’t know how long my patience will last with these kinds of cases,” U.S. Magistrate Judge Margaret Kravchuk said after sentencing a fourth man in U.S. District Court in four years to jail time for a violation of the Endangered Species Act that involved a lynx. “At some point, I may have to impose longer sentences. Seven days of incarceration hasn’t stopped this.”

Kravchuk sentenced William McCoy, 41, of Fayetteville, Pa., to seven days in federal prison for trying to cover up the fact that a Canada lynx, an endangered species, was caught in one of his traps two years ago. McCoy was sentenced immediately after he pleaded guilty to violating the act.

By pleading guilty, McCoy admitted that in December 2008 he removed a lynx’s body from his trap set in the town of Stacyville and carried it about 50 yards away so wardens would not know he had unintentionally trapped the animal.

A charge that he killed a gray jay, a protected migratory bird, in a separate trap that had been set illegally was dropped in a plea agreement with federal prosecutors.

“I’ve based my whole life on [trapping],” McCoy told the judge just before she imposed the sentence. “I’m a good person. I do what states tell me to do, and I trap in a lot of states.”

McCoy, who has no criminal history, told Kravchuk that he did not trap the lynx intentionally but panicked when he found the dead animal in one of his traps and attempted to discard its body.

Assistant U.S. Attorney James McCarthy advocated for a sentence of seven days. Defense attorney Terence Harrigan of Bangor urged Kravchuk to impose a fine rather than jail time.

The judge said McCoy’s sentence of seven days was the same as for two other men previously sentenced on a similar charge involving the same species. She noted that other defendants had intentionally obtained the bodies of lynx or the animal’s pelt.

Last year, Kravchuk sentenced Alan B. Clark Jr., 38, of South Hero, Vt., to seven days in jail for having a lynx carcass. The judge imposed the same sentence on Kevin L. Fortin, 59, of Van Buren in December 2006 and ordered him to pay a $1,500 fine for having a lynx pelt. She sentenced Ricky Learnard, 43, of Van Buren in January 2007 to 21 days in jail for shooting the lynx whose pelt Fortin was found to possess.

A temporary resident of Maine during trapping season, McCoy was warned earlier in the 2008 trapping season that his trap settings did not comply with Maine rules intended to deter the accidental capture of lynx, bald eagles and other protected species, according to the prosecution version of the events to which he pleaded guilty.

Maine game wardens checking on McCoy’s traps discovered boot tracks in the snow on Dec. 4, 2008, leading from a tree where he had set traps before to the dead lynx, discarded about 50 yards away. The tree where the trap had been set had claw marks, fur and other signs that the lynx had been caught and died.

During a subsequent interview with wardens, McCoy confessed to finding the dead lynx in his trap and attempting to hide its carcass in a panic, according to the prosecution version of events. He also admitted to burning the boots he had been wearing at the time after learning that investigators were spotted at the site.

In imposing the sentence, Kravchuk told McCoy that it was the cover-up of the lynx’s death that brought the trapper before her.

The judge stayed the execution of McCoy’s sentence 30 days and requested that the Federal Bureau of Prisons allow him to serve his sentence as close to his home residence as possible.

McCoy has not trapped in Maine since the incident with the lynx, Harrigan said after the sentencing. The trapper paid fines for violations of Maine fish and wildlife regulations in Millinocket District Court before leaving the state for good. The lawyer said that Wednesday’s conviction would not affect McCoy’s ability to obtain licenses to trap and earn a living.

A violation of the Endangered Species Act, which is a federal misdemeanor, carries a maximum penalty of six months in prison and a maximum fine of $25,000.

The death of the lynx in December 2008 as well as other deaths that season became part of a legal battle between two groups — the Wildlife Alliance of Maine and the Animal Welfare Institute — and the Maine Department of Inland Fisheries and Wildlife.

The two organizations had charged that DIF&W was violating the Endangered Species Act by allowing trapping activities that occasionally injured or killed lynx. U.S. District Judge John Woodcock later rejected the groups’ claims that Maine’s trapping policies could cause irreparable harm to the state’s lynx population.