The state's Department of Natural Resources said a gray wolf was trapped and killed on Tuesday in Oneida County and hunters elsewhere across the state reported four kills on Monday as the state-sanctioned effort to reduce the population began.
So far, the state has issued 638 of the 1,160 wolf-harvesting licenses it authorized for the season, which runs through February 28 or until hunters reach the quota of 201 wolves. The licenses cost $100 for state residents and $500 for hunters from outside Wisconsin.
The move to allow the hunting and trapping of the state's wolves has been opposed by some humane societies, which have filed suit challenging the use of dogs in the hunts.
In addition, the Humane Society of the United States and the Fund for Animals said this week they would sue the U.S. Fish and Wildlife Service in federal court to restore protections for Great Lakes wolves. The two groups asked Wisconsin and Minnesota to postpone wolf hunting and trapping until the case is heard.
In Minnesota, where the wolf-hunting season begins on November 3, the state's Court of Appeals earlier this month refused to block the season.
About 4,000 wolves in the northern Great Lakes region - primarily in Wisconsin, Michigan and Minnesota - lost their federal status as endangered or threatened last January.
In the Northern Rockies, conservationists have warred with ranchers and sportsmen over wolves since they were reintroduced to the region by the federal government in the mid-1990s.
Conservationists welcomed the restoration of an animal that had been shot, trapped and poisoned to near extinction in Idaho, Montana and Wyoming. But ranchers and outfitters contended wolves would prey on livestock and big-game animals targeted by hunters.
Moves by the U.S. Fish and Wildlife Service in recent years to strip wolves in the region of federal protections were blocked by lawsuits by conservationists.
Congress last year lifted federal protections from wolves in Idaho and Montana, which have since sought to cut the number of wolves - mostly through hunting and trapping - to as few as 300 from an estimated 1,500.
Wolves in Wyoming were delisted on October 1, the first day of Wyoming's regulated hunting season. There are an estimated 350 wolves in the state.
Under a plan approved by the U.S. Fish and Wildlife Service, Wyoming permits restricted hunting in certain areas but classifies wolves in most of the state as predatory animals subject to unlicensed shooting and trapping.
The Center for Biological Diversity and other groups last month notified the Fish and Wildlife Service they intended to sue the agency over its approval of Wyoming's wolf-management plan.
All three states must maintain at least 150 wolves, including 15 breeding pairs, to prevent relisting.
(Additional reporting by Laura Zuckerman; Editing by James B. Kelleher and Peter Cooney)