The photo was taken in early May 2023, about 10 years after this patch of forest in Yosemite National Park burned in the 2013 Wildfire. Photo by Robert Wilkerson. Credit: Robert Wilkerson
Researchers have found that low- and moderate-severity fires not only benefit many bird species in the Sierra Nevada, but those benefits can last for decades. In addition to several bird species that are already known to be “fire specialists,” a large number of other, more generalist species, such as dark-eyed juncos and mountain tits, have clearly benefited from wildfires.
This study will help landowners make decisions about how to manage forests and fires in a changing fire regime.
IN studypublished in the magazine Fire ecologyResearchers from the Bird Populations Institute, the National Park Service and UCLA examined two decades of bird monitoring data from Yosemite, Sequoia and Kings Canyon national parks for 42 species, as well as up to 35 years of high-resolution fire history data, before collecting the bird data.
They found that 28 of 42 bird species had higher population densities in burned areas, and for most of these species population density remained higher for decades after the fire. The positive effect of fire lasted at least 35 years for 11 species. Only five of 42 species showed a negative (one species) or mixed effect (four species) of fire on population density.
Fire regimes in the Sierra Nevada have changed over the past few decades. Historically, fires have been more frequent in the region, with low and mixed severity fires often controlled by indigenous peoples. These fires helped preserve forests that were dominated by larger, older trees with more open understory. After the 1870s, settlers stopped the practice of burning Indigenous crops and began to suppress natural fires.
More recently, warmer climateincreased drought and fuel accumulation from fire suppression have increased the size and frequency of severe fires across the Sierra landscape.
Forest managers across much of the region now use controlled burns and other fuel reduction techniques to try to stop the current trend of large, intense fires, sometimes called “megafires.”
The benefits of certain types of fires for wildlife are increasingly being recognised, but lead author Dr Chris Ray, from the Bird Populations Institute, said the researchers were most surprised by how long fires lasted to affect bird numbers.
“Given the impact of fire on the nature and structure of bird habitat, and the long process of vegetative succession following a fire, it is perhaps not surprising that birds take so long to respond to fire,” says Ray.
“But even low-severity burns had long-term consequences for some species: for example, western tanagers and hermit warblers were much more abundant at points that had seen mild burns 35 years earlier than at points that had never burned in the previous 35 years.”
Ray points out that 97.5% of study sites in burned areas had mild to moderate burns.
“Our results do not necessarily apply to the very large and intense fires that have become more common in these areas in recent years,” she notes.
Likewise, 42 bird species included in this study were relatively common, so “these results do not necessarily apply to some species that are rare in these landscapes because we could not apply our data-intensive statistical models to species that we did not observe very frequently.”
These results suggest that managing forests to create a mosaic of fire return intervals and fire severity, also known as “pyrodiversity,” should benefit most forest birds.
Ray notes that there is a strong tendency for more positive effects in moderate burns compared to mild burns. “Landowners may be happy to hear that many birds can benefit from burns that are not always mild,” says Ray.
Additional information:
Fires are causing rapid and sustained growth in bird populations in California's protected forests. Fire ecology (2025). Two: 10.1186/S42408-025-00402-2
Courtesy of the Bird Populations Institute.
Citation: Fire provides long-term benefits to bird populations in Sierra Nevada National Parks (2025, October 9), retrieved October 9, 2025, from https://phys.org/news/2025-10-benefits-bird-populations-sierra-nevada.html.
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