On a recent evening not long after dusk, Natalie Ertz stood in a meadow near the Grand Canyon's north rim and howled like a wolf.

There was a good reason for the howl.

Ertz, the executive director of a nonprofit group called Wildlands Defense, was hoping to catch a glimpse of an animal that has been notoriously elusive here in recent days. Seen at least a dozen times by tourists and park rangers, the animal was assigned various possible identities: a Mexican gray wolf, a coyote-wolf hybrid, a wolf-dog hybrid, or a gray wolf from the northern Rockies.

Wolf biologists were tantalized—and stunned—by that last possibility. If it was a gray wolf, the animal had undertaken a spectacular journey, walking hundreds of miles across Utah or Colorado onto the Kaibab Plateau, which is just north of the Grand Canyon.

A gray wolf hadn't been seen in the Grand Canyon area since the 1940s. The predator once roamed much of North America, but was hunted nearly to extinction by the mid-20th century.

But thanks to conservation efforts including reintroduction, the species has rebounded. Today, 1,700 gray wolves roam the West.

The U.S. Fish and Wildlife Service (FWS) is expected to issue a decision as soon as this month on whether to remove gray wolves across the lower 48 states from protection under the Endangered Species Act.

Back on the Kaibab, Ertz—who has tracked and monitored wolf packs in central Idaho for the past six years—howled again, mimicking the call of a younger animal alone and in need.

"It should be mournful," she whispered. "Almost a distress signal, with no hint of aggression, less likely to be perceived as a threat."

Three sorrowful howls floated in the distance, followed by the raucous yips of coyotes joining in the conversation. Ertz was ecstatic.

"A wolf," she said. "There's no mistaking that sound."

Wolves on the Move

Indeed, on that same November evening, the FWS confirmed the mysterious Kaibab animal was a gray wolf. The agency had tested the DNA in the animal's scat and found that its genes matched those of wolves in the northern Rockies.

At about two or two-and-a-half years of age, young wolves set out seeking new territory, often roaming far from their homes, according to National Geographic Young Explorer Jay Simpson, who has tracked gray wolves.

View Images The Kaibab wolf has a radio collar, but it hasn't been transmitting a signal. Photograph by Arizona Game and Fish Department

The looming FWS decision on whether to remove gray wolves from the endangered species list is the result of what the agency calls "three decades of successful management" of the gray wolves by federal, state, and local agencies.

If the delisting comes to pass, the lone Kaibab female can be shot on sight by hunters or trapped—and so can any other wolves attempting to join her. Even if she escapes persecution, she could end her life alone on the rim of the Grand Canyon, never finding a mate.

Carlos Carroll, an ecologist at California's Klamath Center for Conservation Research who has studied wolves, said that delisting "will likely cause long-term harm to wolf populations."

Linking Wolf Populations

The agency also determined the wolf was a female, which biologists say are less likely to disperse from their packs in search of new territory.

Michael Robinson, a conservationist with Arizona's Center for Biological Diversity who advocates for the recovery of top predators across the West, notes that the Kaibab—part of the greater Grand Canyon ecosystem—is ideal wolf habitat.

"This wolf, by validating that the animals have viable [routes] out of the northern Rockies, embodies the hope that wolves can truly recover."

The genetic health of Mexican gray wolves depends on the free movement between isolated populations, according to Carroll, writing in the Journal of Conservation Biology last year.

"Wolves will never be fully recovered if they're just island populations scattered across the West. These populations need to connect up," said Carroll.

He said that the FWS, however, has not developed "a comprehensive strategy" for the recovery of the gray wolf across its entire range.

Instead, the agency has concentrated on recovery in select regions. "By not pursuing a comprehensive strategy, Fish and Wildlife Service management makes movements like we saw with the Kaibab wolf less likely."