Seglund, a species conservation program manager with Colorado Parks and Wildlife, and Macklin, a longtime bird researcher studying pinyon jays as part of her graduate work, are among the scientists trying to answer the questions nagging land managers, bird watchers, and wildlife advocates throughout the Southwest: What is causing pinyon jay populations to plummet? And can sorting out the answer help us better care for one of the West’s most abundant and least appreciated forests?

Pinyon pines’ branches burst into a canopy just above the ground. Without a long trunk hefting these uppermost branches skyward, it’s possible to stand nearby and look almost eye-to-eye with birds in the overstory. Pinyon pines commonly intermingle with junipers, creating an ecosystem known as pinyon-juniper woodlands that grows in places so dry and rocky that most other trees struggle to survive. In these arid regions, pinyon-juniper woodlands provide shade, shelter, and forage for a suite of plants, mammals, reptiles, and pollinators, along with about 70 species of birds—including pinyon jays, which live closely tethered to these trees.

Altogether, the pinyon-juniper ecosystem covers perhaps as many as 100 million acres in Arizona, Colorado, New Mexico, Nevada, Utah, and other parts of the West. John Muir observed vast, continuous swaths of it as he rambled across Nevada in the summer of 1878; he described entire mountain ranges blanketed with pinyons, a “curious little conifer” that exceeded in number all other trees combined. But apart from such anecdotes, there’s little record of the historical extent of these woodlands.

Still, early colonists are thought to have cut millions of acres of pinyon-juniper forest as they built towns and cleared land for farms and ranches. Nevada’s mines and smelters alone consumed an estimated 600,000 to 750,000 acres of pinyon-juniper during its 19th- and early 20th-century silver boom. Well into the 20th century, land owners and managers treated the ecosystem as a wasteland, since the trees aren’t straight or tall enough to produce useful lumber. Untold acres were bulldozed, burned, chemically treated, masticated, or chained, a process by which bulldozers drag chains over the ground to rip out trees. Between 1950 and 1964, ranchers cleared more than 3 million acres of pinyon-juniper forest to create rangeland for grazing livestock.

The jays are compelled to stockpile both by pinyon pines’ short masting season and its loosely understood irregularities. Some years, almost every tree in an area will be laden with seed-bearing cones. Other years, the trees produce virtually none. Pinyon jays are highly dependent on this fat-rich food source: A plentiful nut crop one year correlates to nesting success the following spring. Like most birds, pinyon jays’ reproductive organs shrink to non-functional size outside of breeding season, so that their bodies are lighter for flight. If the previous fall has yielded few cones, the birds may skip breeding. But uniquely, at the mere presence of green pinyon cones in late summer or early fall, pinyon jays return to reproductive condition.

“This co-evolved mutualism is really lovely, but it also figures into the decline of the bird,” Kristine Johnson tells me later. Johnson recently retired from running a pinyon jay research program through the University of New Mexico and is now a senior research scientist with Animas Biological Studies in Durango, Colorado. She has studied pinyon jays for more than 20 years, and seen nesting colonies completely vanish from an area after its pinyons died. As the climate gets hotter and drier in the Southwest, droughts are becoming more common, which can weaken or kill even drought-tolerant pinyon pines. Drought also makes the trees more susceptible to bark beetle infestations, and causes them to produce fewer nuts, both in terms of smaller crops and more years between them. For pinyon jays, this makes reproduction challenging.

“And if they defer and defer and defer [breeding] while they wait for good food,” Johnson points out, “then the population obviously is not going to be maintained.”

Another factor in the jays’ decline may have to do with age of the Southwest’s pinyon-juniper forests. Pinyon pines can live up to 600 years, but in many areas, they’re now less than 140 years old because so many were cut in the 19th and 20th centuries. Since pinyon pines take decades to mature—growing for 25 to 35 years before bearing cones and 75 before yielding robust crops—centuries of forest clearing might now be conspiring with climate change to deprive pinyon jays of their most important food source.

Another piece that scientists and conservationists are trying to figure out is how past and current fire management may impact the jays’ survival. Some think that a century of wildfire suppression has led to overly dense forests that deprive pinyon jays of the mosaic of mixed-age trees in which they thrive. This line of argument favors thinning dense stands to prevent destructive wildfires. But that could also rob birds of nesting habitat. Further complicating the puzzle, other scientists claim that pinyon-juniper forests aren’t adapted to wildfire at all, and have documented projects aimed at thinning fuel loads actually increasing grass cover—a fuel for more wildfires, raising soil temperatures, and depleting living soil crusts, a crucial building block for ecosystem health. Land management practices, like historic and ongoing thinning, grazing and clearing efforts for other endangered species like greater sage grouse, have also changed the woodlands’ composition, but how and to what extent isn’t yet clear.

A conservation strategy for pinyon jays written by a multi-state working group underscores this uncertainty. The causes of pinyon jay decline are “poorly understood,” the report concludes, and likely vary over the bird’s range and over time. Boone, of the Great Basin Bird Observatory, says that a leading contender among the theories is that pinyon pines are becoming less reliable at producing nuts. But drilling into what’s causing those changes, whether it’s shifts in age of the trees or in the climate or in forest management, is work for the coming years.

“If [pinyon jays] have been declining this seriously and for this long,” he says, “obviously there’s some missing piece.”

Finding that missing piece will be key. In 2004, the International Union for Conservation of Nature characterized pinyon jays as a vulnerable species. State wildlife agencies in Arizona, Colorado, Idaho, Montana, Nebraska, Nevada, and New Mexico have prioritized their conservation. The U.S. Fish and Wildlife Service is currently evaluating threats to the species and whether they deserve endangered or threatened species status, with a decision expected in 2028. Unless something changes, advocates like Defenders of Wildlife worry pinyon jay populations could drop by half again by 2035.

In Santa Fe County, Peggy Darr, Defenders of Wildlife’s New Mexico representative, launched a county-wide pilot project to alert landowners to take extra care of what’s generally seen as a hardy desert tree. Scattering mulch at a pinyon pine’s base to cool the surface temperature, surrounding them with straw wattles to slow runoff, skipping pesticides, and watering them might persuade the trees to produce seeds more often. It’s a small-scale effort, Darr concedes, but with pinyon jays declining as fast as they are, it’s time to try anything.

Audrey Kruse, community engagement director with the Grand Canyon Trust, fights entrenched state and federal practices to save clusters of old-growth pinyon and juniper trees, trying to change how an ecosystem that spans millions of acres is overseen one small project at a time.

And to boost public awareness of the plight of pinyon jays, Audubon Southwest partnered with a brewery in Albuquerque, New Mexico, and a meadery in Flagstaff, Arizona, to release signature brews both called “Oh Hey, Pinyon Jay.” These efforts, they all hope, will add up.

The community-collected data might also tease out a glimpse of our future landscape. Climate change is transforming the Southwest, so the question is becoming, where might pinyon jays seek habitat in the decades ahead, and how do people begin protecting those places now?

“What was doesn’t matter much anymore,” Darr says. “It’s more, what can it be moving forward in a new climate regime?”

Walking on a trail outside Santa Fe, Darr points out the remnants of dead pinyon pines scattering the dusty earth. The junipers, not much taller than we are, are still thick enough to obscure the arroyo below, but many of the mature pines have withered to bare, gray branches after recent drought. Still, there’s a pinyon jay colony nesting nearby, and perhaps because of it, pinyon seedlings are starting to emerge. The knee-high, tender green saplings often tuck under or weave into the branches of junipers, fully engulfed in the shade of the more drought-resistant “nurse” tree. Here, they’re not so much gaining ground as trying to reclaim it.

We sit next to a rare surviving pinyon, the air and ground palpably cooler in its shade, and look over the nesting colony. The females incubating nests wait silently through the warm spring afternoon. When the males return with bills full of nuts, the females will erupt into a noisy chorus, the birds passing nuts from bill to bill before settling back into silence. Sometimes Darr sits for hours, waiting to watch them return.