The study, published in the journal Forest Ecology and Management, looked at forest structure and breeding bird communities in three burned and unburned areas of the Nantahala National Forest in western North Carolina between 2016 and 2021. Researchers measured the state of the forest there, including how much tree canopy and how many shrubs survived, and took a count of birds during their spring and early summer breeding seasons.

Within five years of the fires, the researchers found, 71 percent of trees in the most severely burned areas had died, compared with just 7 percent in areas that didn’t burn. But recovery after the fire was swift. Within five years, shrub cover had increased 70 percent. And despite an over 90 percent reduction in tree canopy in the severely burned areas, birds thrived in the aftermath.

By the fifth year, the researchers write, the total abundance, number of species and diversity of birds had doubled in the most severely burned areas compared with the unburned ones.

The researchers spotted birds in the severely burned patches that they didn’t find in the unburned ones, including the indigo bunting, chestnut-sided warbler and eastern towhee. All three prefer shrubs to canopy trees. Even among forest birds, species diversity increased in the most burned areas, and the measures went up in places with the heaviest tree deaths and shrub recovery.

“I think a lot of the forest birds are not as particular as the literature might have previously suggested, as long as there is some vertical structure — like some live trees or standing snags — and cover,” Cathryn Greenberg, a research ecologist with the U.S. Forest Service and the study’s lead author, said in a news release. “Other studies show that even mature forest birds bring their young into recently disturbed areas, where insects and fruits are abundant, to learn how to forage under thick shrub cover for protection.”

More research is needed to better understand how breeding birds might respond to forest fires in the long term, the researchers write. Meanwhile, the study could help drive fire management and forestry practices in the region.