Midnight hikes through the wilderness may help answer important questions about how Mexican spotted owls are recovering.

We knew that we had about a 50-50 chance of seeing what we came to see. But still, we were determined to climb through the night, 2,000 feet straight up the side of a mountain, to find the threatened Mexican spotted owl.

Nobody knows how many of these owls are left in the wild, or what exactly is threatening their survival. But our team at Defenders of Wildlife, along with the U.S. Fish and Wildlife Service (FWS) and the U.S. Forest Service are doing everything we can to find out.

FWS listed the Mexican spotted owl as threatened in 1993, citing habitat destruction caused by logging and wildfires. But the species’ population continued to decline. By 2000, experts determined that the owl’s numbers had gone down by more than 30% in the national forests of Arizona and New Mexico, with population declines as high as 40% in New Mexico. In 2012, the Service revised species’ recovery plan, identifying the primary threat as stand-replacing wildland fire, meaning fires so intense that they kill most or all of the trees in the area.

Yet there are still legitimate questions about what truly constitutes the greatest threat to this owl. Is it really fire? Fires have always been a natural occurrence in the southwest, and it’s likely that Mexican spotted owls adapted to this threat as they evolved alongside it.

In fact, monitoring data for the Mexican spotted owl during recent, high-severity fires shows that the owls return to their nest sites after the fire, and even increase reproduction. This information indicates that these owls actually thrive in a post-fire environment. Their rate of reproduction in severely burned areas is higher than in others, even seven years after the fires.

If natural wildfire patterns aren’t the greatest threat to Mexican spotted owls, what is? Some experts wonder if humans’ widespread manipulation of the forest, often to change fire behavior, could be the larger issue. Forest managers have the authority to do nearly anything they deem necessary to prevent uncharacteristic fires in the owl’s habitat. But when does forest thinning — the cutting down of smaller trees and burning the leftover needles and branches that are most likely to burn — become a threat to the cool, closed-canopy forests and big trees the owl seems to prefer for nesting and roosting? Unlike the impact of wildfires, there is literally no empirical data on how forest thinning and other mechanical forest treatments may impact Mexican spotted owls.

On top of that, it’s hard to gauge how the species is faring if we don’t know how many owls there are now, if their numbers are growing or falling, and if they are spreading to new places or not. If land managers are going to contribute to the recovery of this rare owl, and if our team is going to help them do that, then this is information that we’re going to need to find out.

We are coordinating with the U.S. Forest Service to help get some answers — and that sometimes requires a sturdy pair of hiking boots.

Earlier this summer, I joined Karl Malcolm, PhD, Regional Wildlife Ecologist for the Southwestern Region of the U.S. Forest Service, and two very fit biological technicians from the Bird Conservancy of the Rockies in a long night of hiking. Our destination was a one-square-kilometer survey grid on the very top of the Sandia Mountains, high above the metropolis of Albuquerque. The site was deep inside the boundaries of the Sandia Mountain Wilderness, and it would take us 2 ½ hours to reach it. And since the biologists would need to begin their owl-calling just after dark, we began our trek as the light was fading.

We gazed over the lights below while the bio-techs delighted us with stories from recent surveys where owls had flown in and perched just feet from their device. According to their survey results, we had about a 50-50 chance of calling in the Mexican spotted owl. Sadly, there was no such luck that night. But even that, in and of itself, was a valuable result.

As we staggered back down the trail with our headlamps, I thought about the Mexican spotted owl and all the questions we have about what presents the greatest threat to their recovery and what it will take to protect the species. I returned to my vehicle at 2 AM with no certain answers, but pleased with the knowledge that at least we’re taking steps to get them. It may take some time, but Defenders of Wildlife will be there along the way to ensure spotted owls are around for the next generation.