State officials are planning to start a controlled fire Thursday on Swan Island to burn decayed leaves and grasses and to improve the habitat for birds, including bobolinks, meadowlarks and savannah sparrows.

Swan Island is a wildlife management area owned and operated by the Maine Department of Inland Fisheries & Wildlife. It is in the Kennebec River, just east of Richmond and at the head of Merrymeeting Bay.

The burn also will reduce and eliminate some of the invasive plant species on the island, such as Japanese barberry, autumn olive and multi-flora rose, according to a news release from Inland Fisheries & Wildlife. It will help reduce encroaching shrubs and trees and provide growing space for milkweed, an important food source for monarch butterfly larvae.

“Prescribed burns are a valuable tool for wildlife biologists as these controlled burns improve habitat, regenerate native plants and limit invasive species,” said wildlife biologist John Pratte, who will oversee the prescribed burn.

The burn is tentatively scheduled for Thursday but could be postponed depending on temperature, humidity, wind speed and direction, and ground moisture.

It will take place on two fields on the island, totaling about 10 and 16 acres in area. Trained firefighters from Inland Fisheries & Wildlife, the Maine Forest Service, the Unity College Wildfire Club and a fire services company will carry out the burn.