No one knows how many Mexican spotted owls live across the Southwest, whether it’s as few as 1,000 or as many as 10,000. The last real count, in targeted areas of Arizona and New Mexico, was completed in 2002.
That same year, the Rodeo-Chediski Fire burned across nearly half a million acres of forest lands in Arizona’s White Mountains, long one of the owl’s important habitats. The fire charred wide swaths of the owl’s territory and raised new questions about its numbers and its long-term recovery.
Researchers are only now beginning to understand the impacts of the fire, at the time the largest in recorded Arizona history. One thing that’s become clear to scientists, advocates and owl enthusiasts is that Mexican spotted owls are struggling to survive.
Federal wildlife managers point to megafires like Rodeo-Chediski as among the biggest threats to the owls and to a whole host of species that live in the forests, including bats, small ground-dwelling mammals and larger animals like elk and bears. A fire as destructive as Rodeo-Chediski can disrupt wildlife habitat for decades.
Still, some independent researchers assert that fire has always been a part of the Southwest and that it’s actually the treatments aimed at limiting fires that harm owl populations.
Shaula Hedwall, one of the biologists on the Mexican spotted owl recovery team, is trying to determine the extent to which either of these is true. Her research is a small part of larger efforts across the Southwest to count and monitor the raptors.
What they’d like to know most of all is how the birds are coping alongside forest management activities intended to reduce high-intensity fire risks, such as prescribed burns and thinning.
To do that, those researchers are focusing on breeding pairs, which play a crucial role in assessing populations, whether their numbers are decreasing, increasing or stagnant. Where there are breeding pairs, owlets are born, eventually fledge and may survive to establish new territories.
It’s labor-intensive and costly to track individual owlets using demography studies that follow individuals. That requires capturing birds, banding them and tracking their movements over time, said Hedwall. The last count did it that way, but only looked at small patches of habitat in Arizona and New Mexico and wasn’t a thorough population count or a measure of larger population trends.
Using occupancy rates in specific areas provides a more practical way to assess trends over time. Greater reproduction rates mean the area’s population has a better chance at survival.
“We’re looking right now at the effects of prescribed burning … on occupancy and reproduction in owls, and mechanical thinning and burning on owl occupancy and reproduction,” said Hedwall. “And we’re also measuring changes in habitat that occur from thinning and burning.”
Mexican spotted owls are heat sensitive, according to Hedwall, who is a senior fish and wildlife biologist at the U.S. Fish and Wildlife Service. Because of that, they like cooler microclimates, such as forests of mixed conifers like Douglas fir and ponderosa pine, with stands of Gambel oak sprinkled in.
They like vertical canopy diversity with medium trees to perch on when foraging and sleeping, also called roosting. And they like taller, older trees to roost and nest in. If the area is sloped and north-facing, it’s even better.
Hedwall was a co-author on a March paper assessing habitat, a study led by Chris Witt from the U.S. Forest Service, with other Mexican spotted owl experts, including Gavin Jones and Joe Ganey, both from the federal Rocky Mountain Research Station.
In the paper, the team analyzed owl habitat from 1986 to 2020, using satellite imagery, Google Earth Engine and modeling to classify the footprint of the Rodeo-Chediski Fire into four distinct categories based on the degree to which patches of habitat aligned with spotted owl preferences.
They estimated that over 35 years, nearly 83% of the forest type that matched preferred owl habitat pre-fire had changed post-fire. More directly, they found that it reduced habitat for roosting and nesting, two key behaviors that indicate stable owl habitat, by 38%.
Related: How the Schultz Fire reveals long-term costs of big wildfires, from floods to habitat loss
Researchers were able to create a living map, said Jones. As fires roar across the landscape, models of suitable habitat are overlaid with recent events to see where owls could persist.
The new technology has been revolutionary for monitoring habitat. Researchers can now go all the way back to satellite imagery records and combine them with current events, allowing them to make determinations about long-term habitat trends.
Jones and his colleagues recently published two more papers on changing spotted owl habitat using the same technology. Habitat isn’t just vegetation, he said, and his two papers add other elements such as climate and topography to map owl habitat at a finer scale. Two additional areas they looked at lost about 25% of suitable spotted owl habitat.
“I really think this changes everything,” said Jones. “We can essentially, at any time when a fire happens, when a drought happens, when some type of management operation happens, we can just remap spotted owl habitat almost instantly.”
His isn’t the only research with sobering results. Michael Lommler, the Colorado data specialist at the Great Basin Institute, submitted his dissertation on spotted owl habitat selection after the Rodeo-Chediski Fire.
He looked at 20 protected activity centers, or PACs, which are areas where spotted owls are known to roost and nest, during the breeding season between 2014 and 2016. He compared current observations with historical data provided by the Forest Service.
According to his research, the presence of breeding pairs was reduced by 50% within the perimeter of the fire. Before the Rodeo-Chediski Fire, owl pairs were present at the same rate in PACs both inside and outside the fire perimeter. After the fire, site occupancy for both breeding pairs and individuals was lower where high-severity burning occurred.
“Spotted owls are looking for certain levels of forest structure with high canopy cover, large mature trees, generally looking for shady, cool spots in which to nest and roost,” said Lommler. “And because of the effects of the wildfire, there is simply less of that habitat available.”
To help halt some of that habitat loss, federal biologists, and researchers like Lommler, are recommending an array of fire management tactics that include thinning, prescribed fire and managed fire.
Nearly 90% of the Rodeo-Chediski Fire occurred on the Apache-Sitgreaves National Forests and the Fort Apache Indian Reservation. Since the fire, according to a forest representative, over 45,000 acres within the footprint of the fire have undergone treatments, either mechanical thinning, prescribed burning or replanting. Within the perimeter of the Rodeo-Chediski footprint, over 25,000 acres have undergone prescribed burning, and over 18,000 acres have been mechanically thinned.
There’s another theory that seems to contradict that work. A team of independent researchers says that the Southwest is well adapted to fire and so are Mexican spotted owls.
Fires, even large ones, are a part of the natural cycle and can even benefit owls, they say. After periods of fire, forest stands open up, and hunting becomes easier for birds as they soar through stands of singed trees.
It’s the treatments to reduce fire that are actually harming owls, they contend, primarily through salvage logging, which occurs after a forest is burned and contributes to habitat loss. During this process, land managers remove all the sellable trees.
But instead of methodically removing trees, entire patches of forest are razed, turning potential habitat into stump forests that are of no use to the birds, the researchers argue. That reduces some of the structure the owls need to perch and feed, reducing habitat.
Chad Hanson has worked on spotted owl research projects for over 25 years. He is the director and principal ecologist at the John Muir Project, a research organization that advocates for land management policies that prioritize ecological health. He’s also one of the main proponents of the “fire is good for owls” concept.
He’s authored several studies that look at the effects of logging on owl populations. According to his findings, the burned forests are intricately connected to the health of spotted owls.
“When (the Forest Service) is talking about thinning and thinning of small trees and under undergrowth, they’re not talking about pruning shears,” says Hanson. “They’re talking about chainsaws and bulldozers and giant feller bunchers and massive, multi-ton logging machinery, tearing through the forest and taking out huge old trees.”
Logging in national forests used to be a widely accepted major threat to spotted owls as recently as the 1980s, said Monica Bond, a wildlife biologist and biodiversity activist with the Wild Nature Institute. In the decade that followed, the Endangered Species Act listing of the northern spotted owl halted many logging projects in the Pacific Northwest.
The timber wars marked a pivotal shift, when the science of logging the ecological harm done to forests was thrust to the fore of the debate between conservation and commerce.
Long regarded as overgrown and in need of management, old-growth forests were seen by the public as a solution to climate change. The rainforest along the Pacific Northwest coast, the U.S. Forest Service estimates, stores 2,100 million metric tons of carbon per year, which is 24% of car emissions in Oregon and Washington, one of the largest natural carbon sinks in the country.
At the same time, conservation groups such as the Sierra Club were advocating for greater protections. Undervalued and misunderstood, old-growth forests and the benefits they provide were abstract to many. The northern spotted owl became an effective face for why these forests needed protection.
Hanson says it’s at this point that the Forest Service, logging industry and some politicians started to rebrand, replacing the word “logging” with more benign terms such as restoration, thinning and fuel reduction.
It was around this time that the perception of threats started to shift from logging to fire. To save spotted owls, the Forest Service contended, fires needed to be prevented.
In 2007, five years after the Rodeo-Chediski Fire, the Forest Service issued a plan to burn 162,000 acres within the burn area to reduce fuel loads. Despite this plan, nearly 20 new fires have occurred in the area since 2002. And nearly 30,000 acres have been salvaged logged, according to Bryant Baker, a GIS map specialist and conservation director at the nonprofit Los Padres ForestWatch.
In short, none of the efforts to reduce fires actually prevented future fires from happening, said Bond, the biologist, but instead led to less suitable habitat for Mexican spotted owls.
“I found they actually liked to forage in the areas that had burned severely when it’s closer to their nest,” Bond said. “So they did forage in the unburned stuff and the lightly burn and moderate, but they showed a preference for foraging in these high severity burned areas closer to their nests.”
These newly burned stands, rather than hindering owl growth, were encouraging it, Hanson said. The patchy structure, Bond said, provides clear sight lines and minimum cover for prey.
A useful contrast that Hanson points to is the Horseshoe II fire that burned in the Chiricahua Mountains of southeastern Arizona in 2011. It is the fourth-largest fire to burn in Arizona.
According to his research, the area where the fire occurred is mostly protected from logging. This offered a good opportunity to observe the response of Mexican spotted owls to burned landscapes. The work he cited found that owl populations had doubled in the area three years after the fire.
The research concluded that owls used these burned areas, called snag forests, to forage. In burned areas, prey boons were observed as the small mammals, insects and reptiles that the birds feed on seek cover that doesn’t exist.
Instead of salvage logging and thinning efforts to reduce fuels, Bond suggests the idea of “proforestation,” which is just letting nature take its course and allowing tree regeneration on its own.
With climate change fueling the dry conditions for wildfires to thrive, the likelihood that fires continue to burn across the West is growing. The 10 largest fires in Arizona have all occurred in the two decades following Rodeo-Chediski in 2002.
As fire regimes continue to change, biologists expect owls to suffer if the status quo is maintained. Whether by direct fire setting or indirect fire management, forests are being altered by human activity.
Hedwall, the USFWS biologist, points to the connections between the climate, the environment and how humans and animals interact with the world. Less precipitation means more fires and less vegetation productivity, which leads to less food production, such as small mammals, for owls.
As a member of the Mexican spotted owl recovery team, she works with partners to recover Mexican spotted owls and she needs to understand how forest management can be used to support owl recovery.
She recently started her day on a breezy afternoon in the Coconino National Forest, just west of the area where the Rodeo-Chediski Fire burned.
She was headed to one of the spotted owl Protected Activity Centers that her team is monitoring. This area had not been burned and for now, it’s a reference site that’s being monitored to see how the owls fare in untreated sites compared to those where prescribed burning and mechanical thinning have occurred.
The forest is lush, the soil is rich and the canopy is so dense that only dabbled light permeates the forest floor, nearly 100 feet from the treetops. This particular site is the 600-acre management area for a breeding pair of owls.
After four hours of trekking up and down slopes, through underbrush and over tree trunks, Hedwall whispered, “shhhh!” She heard the distant hoot of a male up the side of the mountain. She raced up the slope, colleague Jamieson Arnold, who works for the Forest Service, in tow, recording the time, date and location.
They wanted to spot the owl, hoping to locate the nest. The faint contact call of a female owl followed, telling the researchers they were in the right area.
“Wait, I hear them, it’s that way,” Hedwall said. “They both are calling. It was a male call. And the female gave contact calls!” She and Arnold darted higher up to see if they could locate the source of the sound.
Another hour’s worth of searching produced no leads. The calls were heard, but no owls or nests were seen that day.
On day two, Hedwall felt renewed. She was in a treatment area where a prescribed burn was slated to take place.
Julia Camp, Arnold’s manager, joined Hedwall, this time in a new PAC. The owls have continued to use the site since the Forest Service and USFWS burned the area in 2017. It didn’t take long before the hoot of the male echoed through the forest. This time the call was loud, crisp and clear.
He was near where they were standing. After a few minutes of craned-neck searching, they found the nest. Hedwall went higher up the slope to get a better vantage point.
“I see a fuzzball! I might see two fuzzballs,” she exclaimed in a hushed shout. “That’s what you’ll see with raptors, one small, one big. They’ll probably fledge next week.”
She was feeling lucky, so much so that she was keen to check out another nest site several miles away. The researchers hadn’t visited this site since April. This time, the male made his presence known, not with a sound, but by flying directly toward the two biologists. The nest was near.
“He’s going to follow us,” said Hedwall. Perhaps he was keen to escort the humans out of the area.
“Found it,” she declared after searching a patch of forest surrounding an old Gambel oak. The female was sitting on a chick, maybe two, deep inside a hollowed-out cavity.
One of the most significant drivers in the efforts to understand Mexican spotted owl populations, where they live and the effects of forest management is the 2012 recovery plan and a subsequent 2013 lawsuit filed by WildEarth Guardians.
The recovery plan mentions site-specific actions federal agencies should take to measure and assess spotted owl populations to determine the status of the species. The document essentially functions as a roadmap to delisting or uplisting if conditions worsen.
Following its publication, the New Mexico-based conservation organization alleged that the Forest Service had abdicated its responsibility to assess how the birds were responding to activities related to logging. The group also said USFWS had ignored potential impacts on spotted owls.
WildEarth Guardians fought for the protection of spotted owls in the 1990s. Twenty years after Mexican spotted owls were listed as threatened in 1993, the conservation group said the Forest Service intended to weaken some of the guardrails put in place to protect the birds.
In 2019, a Tucson-based federal judge partially agreed with them and placed an injunction on some logging activities in New Mexico and Arizona.
In 2020, the two federal agencies reached an agreement with the group. As a part of that agreement, both agencies agreed to monitor Mexican spotted owl populations. The outcome could affect the bird’s listing.
A slew of research projects has addressed issues raised by lawsuits. In addition to Hedwall’s work, the Forest Service contracted with Bird Conservancy of the Rockies in 2013 to assess Mexican spotted owl populations across portions of their range until 2025.
Their work covers over 200 randomly selected sites across Arizona and New Mexico. The sites are represented by square kilometer patches on forest land, the primary habitat of Mexican spotted owls. Each site is visited by a team of scientists who check each plot annually.
According to Marion Clement, the Mexican spotted owl coordinator for the organization, the more data that’s collected, the firmer their foundation for making conclusions.
“We use a loudspeaker or game caller to play a territorial call that a Mexican spotted owl would make, and during the breeding seasons, the owls are very tuned in to defending a territory,” said Clement. “So, if they’re within earshot, especially if they’re nesting, they will come in and make themselves known.”
The spotted owl’s recovery is measured by trends in populations over a 10-year period and trends in habitat. While the final verdict is still out, Clement cautions that some of the tentative data that they’ve collected do not bode well for delisting.
Researchers are seeing a slight decline in breeding pairs. “It’s not … drastic, but it’s there,” she said. “When we detect … single owls, they’re modeled separately from pairs. And those also seem to have a slight decline.”
As environmental conditions such as fire continue to alter Mexican spotted owl habitat, these can be used to tell scientists what suitable habitat still exists across large swaths of the Southwest.
While all groups studying owls have seen data that’s resulted in less than desired outcomes for spotted owls, Hedwall offers a key to why some of the current conclusions should be approached with care.
The main element to determining population trends, she said, are long-term studies over years and vast areas, something Clement is currently working on.
While forested habitat for Mexican spotted owls may be changing because of climate change and forest fires, the owls may find refuge in the many canyons that dot the landscape.
Hedwall also challenges the idea that the owls rely heavily on severely burned forests, saying that those findings may be overstated. They use these areas, and many others, for foraging, she said, but the more important factor for owl populations is the need for nesting and roosting habitat. Without those, there’s no new population source.
“Having burned, high intensity burned landscapes everywhere is not good for nest and roost habitat for owls,” Hedwall said. “They will use those areas for foraging as long as they’re not too big, but it’s not nest/roost habitat long-term for these birds.”
Later on the second day in the field, another surprise came: Arnold, the Forest Service scientist, had radioed from the other site. His team had found a nest where he and Hedwall had been the night before.
It was encouraging news for the researchers. With three separate breeding pairs, all with owlets, the prospects for the Mexican spotted owls appeared to be good in this part of the forest this season, despite the planned burning and mechanical thinning.
Hedwall and Camp spent that Friday inputting all of the information they recorded that week into their database. But their work to determine how forest management activities affect owls won’t end for a few years.
The prospects of forest management and conservation coexisting doesn’t seem far off, based on their work. It’s about very specific site actions that allow managers to treat areas of the forest while also leaving some areas intact, she cautions.
“What I’m trying to do is not only maintain or enhance existing habitat (Mexican spotted owls) are using for nesting and resting, but also work with people to create habitat that will develop into nesting and roosting habitat into the future,” she said.
“I hope … we’re going to learn a whole bunch about how owls are actually using the landscape and that we’re going to be able to use that information to inform forest management moving forward so that we can maintain habitat for these birds.”
Lindsey Botts is an environmental reporter for The Arizona Republic/azcentral. Follow his reporting on Twitter at @lkbotts and Lkbotts on Instagram. Tell him about stories at firstname.lastname@example.org
Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at environment.azcentral.com and @azcenvironment on Facebook, Twitter and Instagram.
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