Fires Give Birds a Lasting Boost in Sierra Nevada Parks

In the forests of California’s Sierra Nevada, what once looked like destruction is turning out to be renewal. A new study finds that low- and moderate-severity wildfires can benefit bird populations for decades, offering fresh evidence that fire is not always the enemy of wildlife it is often made out to be.

The research, published in Fire Ecology, examined more than twenty years of bird-monitoring data from Yosemite, Sequoia, and Kings Canyon National Parks. It found that 28 of 42 bird species had higher population densities in areas that had burned. For many of them, those population boosts persisted for more than 30 years after the flames went out.

A Phoenix Effect for Forest Birds

On a bright May morning in Yosemite, the charred skeletons of pines still stand, silvered by ten years of sun and snow since the 2013 Rim Fire. Between them, patches of green and gold shimmer with new life: shrubs, saplings, and the darting shapes of Mountain Chickadees and Western Tanagers. The landscape looks raw but alive. That, say scientists, is the point.

Lead author Dr. Chris Ray of The Institute for Bird Populations said the team was surprised by just how long the effects of fire lasted.

“Given the effects of fire on the nature and structure of bird habitats, and the long post-fire process of vegetative succession, maybe it’s not too surprising that birds are responding to fires for so long,” said Ray. “But even low-severity burns had lasting effects on some species: for example, Western Tanager and Hermit Warbler were much more abundant at points that had experienced a low-severity burn 35 years ago than at points that never burned in the previous 35 years.”

For decades, U.S. forest policy focused on suppressing fires. But in the Sierra Nevada, that approach interrupted natural cycles. Before European settlement, fires, often started or managed by Indigenous communities, kept forests open and diverse. With suppression came dense, fuel-rich stands and an increased risk of catastrophic “megafires.”

The study suggests that restoring a patchwork of different fire intensities and return intervals, what ecologists call “pyrodiversity,” can benefit the majority of forest birds. Fires that burn with mixed severity seem to create a mosaic of habitats that support a wider variety of species over time.

Lessons for Land Managers

Out of the 42 species analyzed, only five showed negative or mixed effects of fire on population density. The rest, from juncos to towhees, seemed to find new opportunities in the wake of flames. Moderate burns, in particular, appeared to offer the strongest and most enduring benefits. That finding could reshape how park managers think about prescribed burns and wildfire response.

Dr. Ray emphasized that nearly all of the burned sites in the study experienced low to moderate severity fire. In other words, the results may not apply to the massive, high-intensity wildfires that have plagued western landscapes in recent years.

“Our results don’t necessarily apply to the very large and high-severity fires that have been occurring more often in these landscapes in recent years,” Ray said. “But land managers might be heartened to hear that many birds might benefit even from burns that aren’t all low-severity.”

Researchers note that these national parks act as ideal “natural laboratories,” relatively undisturbed by logging or development. That makes them perfect for studying long-term ecological change. Since 1998, the National Park Service’s Inventory and Monitoring Program has gathered systematic bird data that underpins studies like this one.

Unfortunately, the future of that monitoring effort is uncertain. Funding for The Institute for Bird Populations to continue bird surveys in the Sierra Nevada parks was cut after the 2025 field season, just as the ecological story of fire and renewal was becoming clearer.

Still, the message that emerges from the study is an encouraging one: when fire returns at the right scale and intensity, life often follows. Burned forests are not just scenes of loss—they are the beginning of a long, complex renewal that keeps the Sierra Nevada’s skies full of wings and song.

Fire Ecology: 10.1186/s42408-025-00402-2