CHEYENNE, Wyo. (AP) — Wyoming's second wolf hunting season started this week and the state has lowered the quota of wolves available for hunters to kill.

Wyoming Game and Fish Department spokesman Alan Dubberley says hunters have reported killing four wolves since the season opened Tuesday in the designated trophy hunting zone bordering Yellowstone National Park. The state classifies wolves outside the trophy area as predators that may be shot on sight.

Hunters killed 42 wolves in the trophy zone last year. Dubberley says the quota there this year is 26 wolves. He says the state expects to end the season with no less than 160 wolves left in the trophy zone.

Environmental groups are still challenging the federal government's decision to end federal protections for Wyoming wolves.