The Search for Mexican Spotted Owls moves to Colorado

Article by Chas S. Clifton

Wildlife – August 1995 – Colorado Central Magazine

The fluffy young owl made its begging call, something between a rising whistle and a puppy’s whine. Its plumage was a combination of a hatchling’s down and more mature feathers — it could fly, but it was not likely to go far, and if it did fly, I could follow it on foot up the ravine through the gloomy, deep-forest light.

It was a Mexican spotted owl, Strix occidentalis lucida, born that spring in a heavily wooded canyon on the east side of the Wet Mountains in Custer County — which may come as news to the editors of some field guides. It had two siblings: I had come upon all three sitting in a line on a granite outcropping, their downy heads gleaming in the half-light of an overcast late summer afternoon, their brown eyes bottomless.

The woods were quiet, gray and green. I watched the owl from the corner of my eye, having moved to within about twenty feet of it but not wanting to crowd it to the point where it would fly away. It would swivel its head toward me, then look away downhill, watching for its parents. Its nestmates perched in nearby Douglas firs, each one shadowed by a member of our banding team. “Dad” at that very moment was being banded, weighed, and measured somewhere down the ravine. “Mom” had eluded us, but we knew she was in the area.

The forest muffled all human sounds. I sat quietly, glancing sideways at the owl occasionally, letting my eyes drift away. I remembered a U.S. Fish and Wildlife Service man talking about an African nation with a rhino population so threatened by poachers that each individual beast was guarded by two rangers armed with old British .303 Lee-Enfield rifles. By the time the banding team came hiking up the draw, led by Forest Service owl researcher Charlie Johnson carrying his 20-foot noose pole, I was deep into the fantasy of uniformed “owl rangers” patrolling the woods.

But minutes later I was holding the young owl, all fluff and bones, a kitten with wings, its chances of reaching its first birthday one in three at best.

Unlike the cosmopolitan great horned owl, the Mexican spotted owl has more narrowly defined habitat needs. Here on the northern edge of their range they prefer dense, multi-story, closed-canopy forest and narrow, wooded canyons to live in. Not only does this give them some protection against the horned owls and other flying predators (hawks, for instance), but in the Southwest they may require protection from summer heat as well.

In Colorado spotted owls seem to prefer mixed conifer forests (often ponderosa pine and Douglas fir) at about 7,000-8,000 feet elevation for nesting. In the canyon country of southern Utah, however, they may be at lower altitudes but in even more vertical settings.

The spotted owls’ rarity was only of interest to a limited number of birders and wildlife biologists, of course, until the fuss over logging old-growth forests in the Pacific Northwest erupted in the 1980s. (As a former Oregon resident, I can attest that fluctuations in the housing market, the export of unmilled logs, and increasing automation in the mills had been eliminating timber-industry jobs since at least the early 1970s, well before the average person had even heard of spotted owls.)

When intense study of the northern subspecies began, at least two-thirds of its old-growth habitat was already gone. Like the Tennessee snail darter, the northern spotted owl became a convenient symbol to attack or defend. Making the owl the issue is easier and less mentally taxing than cutting through the public-relations smokescreen to discuss political pressures on the Forest Service to harvest trees faster than they grow or how private companies could clearcut their lands, knowing they could switch over later to cheaper state or federal forests.

Several years later, in 1987, spotted owls became an issue in the Southwest — this time the Mexican subspecies, which lives from southern Colorado south into Mexico. A pair of owls was found nesting in a planned timber sale that year on the heavily logged Lincoln National Forest in southern New Mexico. Mindful of their colleagues’ difficulties in the Northwest, local Forest Service officials closed down part of the sale and began developing a management policy to try to head off similar polarizing controversies.

In 1989 the U.S. Fish and Wildlife Service (USFWS) was petitioned to list the Mexican spotted owl as a “threatened” species, the same status given the northern subspecies. A “threatened” species, by federal definition, is one likely to become “endangered” within the foreseeable future. “Endangered” means a species is in danger of extinction in all or a significant part of its range.

Public hearings were held in Arizona and New Mexico in January and February 1992. People responding to the listing proposal tended to be about evenly divided except in Flagstaff, where timber companies bused in hundreds of employees to weight the process. In addition, a USFWS spokesman said, the agency received large numbers of identical form letters protesting the proposal, mixed in with more genuine public comments.

Serious inter-agency study of Colorado’s spotted owls began in 1989, involving the Forest Service, Colorado Division of Wildlife, Bureau of Land Management, National Park Service, and the Bureau of Indian Affairs on the Southern Ute and Ute Mountain reservations. The newness of the subject meant there were few experts, but that in turn made it possible for people like Mary and me — strictly average birders — to make a real contribution to ongoing research.

Our involvement started at a table staffed by local Forest Service personnel during the little 1990 Earth Day fair in Ca$on City, held in the Wal-Mart parking lot at the edge of town. District Ranger Cindy Rivera said she was seeking volunteers to look for spotted owls. No one on her staff had any ideas if the owls were in the area or even had a tape of what they sounded like, but a local Audubon Society member copied a Cornell Laboratory of Ornithology recording for us.

In early August 1990, through perhaps 30 percent forethought and 70 percent luck, we located a pair. Since our two birds were half of the San Isabel National Forest’s known population at that point, we were, by local standards, “experts.”

Together with the northern spotted owl (S.o. caurina) Mexican spotted owl and the California spotted owl (S.o. occidentalis), this is one of three subspecies. (Its noisier eastern cousin is the barred owl, whose “Who cooks for you?” call is familiar in woodlands almost anywhere east of the Great Plains and in some parts of the Pacific Northwest.) Often a little grayer than the northern spotted owl — some birders like to say “sunbleached” — it occupies a distinct range stretching from the mountains of Mexico up into forested parts of Arizona, New Mexico, southern Utah and Central Colorado.

Central Colorado may represent the Mexican spotted owl’s northernmost range. One historic record comes from Queen’s Canyon on the northwest edge of Colorado Springs: a spotted owl was shot there in the 1920s.

Now, researchers have begun to find spotted owls as far north as the mountains west of Sedalia. Others are breeding in Frmont and Custer counties and in southwestern Colorado around Mesa Verde. But the overall numbers are low, and, I suspect, have been for a long time. By comparison, current estimates of the total population in the Southwest hover around 2,000 birds (exclusive of whatever spotted owls live in Mexico.) There are not yet enough data to show whether the population is stable, declining, or increasing.

As beginning birders turned owl contractors, Mary and I have encountered reactions from our friends ranging from blank looks to an assumption that our work verges on the mystical. One friend suggested that we must have time for lots of deep, philosophical discussions during our long walks in the woods.

In fact, based on our and others’ experiences, the two most frequent conversational openers among owlers are “Did you hear something?” and “Are you sure we’re on the trail?” Listening, not talking, is the owler’s main job. Often, however, owls must be challenged into vocalizing.

As many birders know, the invention of the portable tape recorder made locating owls much easier. The owler merely walks on a quiet night through good habitat, pausing at intervals of a quarter mile or so to play a territorial call — in our case, a four-note series similar to the barred owl’s but with a different rhythm and somehow “barkier.”

If a spotted owl is within earshot, it will usually answer. Sometimes owls of different species will answer — or even birds other than owls. For instance, we have heard prairie falcons respond angrily from their cliff eyries when a spotted owl call was broadcast across the canyon. Great horned owls (a predator on spotted owls) may reply, in which case we stop calling and move on. Smaller owls such as saw-whets and flammulated owls may also respond; they too get written up on our contact sheets and ultimately entered into a computer data base maintained by the BLM.

The tape recorder makes for a consistent call, but naturally it is more satisfying to get a response to one’s own vocal owl imitation. Some owlers get so good they fool each other; others are less concerned about perfect imitations. “You can bark like a dog, and [spotted owls] will respond,” remarked a sanguine Forest Service biologist.

If an owl is located, all researchers next want to know if it is part of a nesting pair. One way they find out is by “mousing” it. If they can find an adult owl roosting during the daytime, they will place a pet shop mouse or gerbil on the ground nearby and back off. The owl’s interest in the mouse overcomes its shyness at this point; almost immediately it flies down and grabs the free dinner. (Photographers also use this technique to get dramatic pictures of owls flying down with talons out — the tethered mouse is outside the picture.)

At this point, an owl with a mate or young nearby will frequently take the mouse to them while the researchers, running through the forest, attempt to follow it — often the only way to find a nesting ledge on some rocky outcrop.

Roosting owls can often be captured for banding during the daytime. While they are not blinded by sunlight, as folklore has it, they are less active, counting on their camouflage-pattern plumage to make them invisible. Researchers can snag them with telescoping noose poles: the stiff wire noose catches on the feathers but only holds the owl loosely, enabling team members to grab the bird and hold it long enough for banding.

Even with marking and banding, owls’ movements are still mysterious. Research from the Northwest shows that spotted owls can move to lower altitudes in winter, but they are not long-distance migrators. According to Joseph Ganey, a leading Southwestern spotted-owl researcher, some Arizona owls carrying tiny radio transmitters were found to migrate as much as 30 miles in winter, from mountain breeding grounds into lower, warmer areas.

How far immature owls will move as they disperse from their nests is still unknown, he said. In Arizona (where the owls have been studied more intensely than in Colorado), they apparently have crossed expanses of desert in order to populate isolated mountain ranges, Ganey said.

Studies of young owls’ dispersal should progress rapidly as researchers begin mounting tiny radio transmitters on juvenile birds. Sewn to a tail feather, the transmitters will eventually fall off at molting, but by then trackers should have an idea if, for instance, spotted owls are moving down in altitude during the winter.

If they are moving down, they return to their nesting range before Rocky Mountain winters have abated, for like other owls, the Mexican spotted owl breeds early in the year. In late March, I stood on old, crusted snow photographing one of “our” owls, now mature, as he proclaimed his territory from a spruce limb.

When my wife and I walked away down the canyon, he followed us for about a quarter mile, now thoroughly angry at the intrusion. His barking hoots carried even over the tumbling noise of a swollen creek — he was still there, he had come through the winter, and this was his place.

Chas S. Clifton and his wife, Mary Currier, live in Wetmore. They have carried out owl inventories for the Bureau of Land Management’s Cañon City District for the past four summers.