Out With The Owls

Biologists mark a decade of counting Mexican spotted owls


It's a fine thunderstorm-and-sunshine sort of afternoon on the Mogollon Rim, the pine-covered escarpment that towers above Payson, and we've come calling on a pair of Mexican spotted owls.

Standing at the edge of a steep, rain-soaked canyon that's walled by skyscraper pines, shade-stunted oaks and delicate ferns, Jim Harvey, a seasonal worker for the U.S. Forest Service, draws his mouth into an "O" and belts out four mellow hoos -- a typical owl how-do-you-do.

We wait quietly, but minutes go by and his call goes unanswered.

He draws a deep breath and tries again. "Hoo-hoohoo-hoo."

Nothing. Just the insistent squawking of a flock of jays high in the treetops.

But to Harvey, who is overseeing a six-person team that's counting Mexican spotted owls this summer for the Forest Service, the chattering jays are unwitting informants.

"That's a good sign," he said, pointing toward the sound of the fussing birds.

"The jays like to hang around the owls and nag them. Chances are, if we find the jays, we'll find the owls."

The Mexican spotted owl, which is cousin to the northern spotted owl of the Pacific Northwest and the California spotted owl of southeast California, was listed as a threatened species in 1993 due to habitat changes caused by logging and the threat of catastrophic forest fires.

Wildlife biologists for the Forest Service have been surveying owl populations and tracking their breeding success rates since 1989. They use that information to manage timber sales, prescribed burns and recreation projects in ways that won't endanger the owls or their habitats.

In 1994, 841 spotted owls or mated pairs had been found in Arizona and New Mexico.

To date, 70 owls or mated pairs have been found in the Tonto National Forest, many of them along the Mogollon Rim, and their numbers seem to be stable, said Don Pollock, who heads up the Tonto National Forest's zone wildlife staff.

In search of the elusive birds, Harvey and I push past the wispy saplings and low-growing oaks competing for sunlight near the road and step into the sun-filtered world where the spotted owl and a few other predators rule the food chain.

This is prime spotted owl real estate -- dense forest with a multi-storied canopy that protects the spotted owls from their enemies, larger raptors such as the great horned owl and the goshawk, while they hunt for woodrats, rabbits, beetles, mice and voles and a wide menu of other small prey.

It's still more than an hour before sunset. The fading afternoon sun is trickling through the trees as we clamber down the steep side of the hill, where the forest floor, made spongy by years of fallen leaves, springs under step.

It's a bit early for the owls. They rest during the day and hunt after the sun goes down, but Harvey is sure we can rouse them from their routine. We squirm through bushes and duck under trees, shaking showers of raindrops off the leaves and onto our heads before we find the jays making a fuss around a towering, 250-year-old pine tree.

Harvey, a wildlife biology graduate from Northern Arizona University, hoo-hoos another greeting. The owls use the four-note hoot as a territorial call or to find their mates, so a good imitation normally gets their attention.

Suddenly, a ghostly reply resonates from the distance -- "hoo-hoohoo-hoo" -- and a rush of air brushes our faces as a female owl swoops quietly onto a branch overhead.

"That's Rita," Harvey said, smiling with gratification. "You've gotta give them Spanish names."

The brown feathers on her breast and belly are freckled with white spots, camouflaging her against the surrounding tree bark.

When she's hunting, she will sit on a branch, camouflaged near the trunk, while she waits to swoop down on the first unwary animal that wonders into range.

Rita is about 19 inches tall, slightly bigger than her mate, Miguel, who flies up a few moments later on heavy, methodical wings. Spotted owls normally weigh between 1 and 1 3/4 pounds and the females, which have an average wingspan of more than 3 1/2 feet, are normally slightly larger than the males.

The birds, which have round heads, large brown eyes, dish-shaped faces and rounded wing feathers, are tailor-made for nighttime hunting in their native forest ranges throughout Arizona, New Mexico, southern Utah, Mexico and southern Colorado.

Their faces are concaved like satellite dishes, which helps them divert sound waves to their ears. Their ears, small holes in the sides of their skulls, are offset so they can triangulate sound, an ability that allows them to pinpoint the faintest shuffle of clawed feet.

Their large, round eyes, while unable to see color, are densely packed with light receptors, giving the birds keen night vision. And although their eyes are fixed in their heads, they can turn their heads 270 degrees to keep an eye on who's coming and going around them.

In dense forest, the spotted owl uses its rounded wing feathers to deftly maneuver around tree trunks, vines and bushes while chasing down its prey.

In these surroundings, the spotted owl is almost unstoppable -- but such plum accommodations are at a premium.

About the Mexican Spotted Owl
The Mexican spotted owl is a nocturnal, woodland owl that prefers to nest and hunt in mixed conifer forests ranging throughout Arizona, New Mexico and Mexico.

Spotted owls primarily nest in stick nests built by northern goshawks, clumps of mistletoe, large tree cavities, broken treetops and in rock faces. Old nests are not repaired before eggs are laid and are often reused year after year.

Clutch sizes range from two to four eggs, but averages two to three eggs. Eggs are laid every three to four days, usually in April.

Owlets hatch in early May and leave the nest after 34 to 36 days. They reach full development in 65 days. The juvenile mortality rate for spotted owls is high due to inexperienced flight, navigation and hunting skills.

The spotted owl's typical advertisement call is a mellow, four-note hoot.

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