"This is a significant milestone in the process of restoring a species to its historical habitat," said Keith Day, a wildlife biologist with the Utah Division of Wildlife Resources, in a statement. "It proves that Utah still has suitable habitat for these magnificent birds and that the selection of the Arizona-Utah region for establishing a population was a valid choice."
An experimental population of California condors was released in the Vermilion Cliffs National Monument in northern Arizona in 1996. It did not take long for the large raptors to head north to the canyon country of Zion National Park.
It has, however, taken them a while to hatch an egg.
Zion National Park biologists report that condors have shown breeding and possible nesting tendencies in the park over the last four years but none has led to a hatching. One pair had shown particular interest in nesting in Zion, but one died in 2012 and another in 2013 due to lead poisoning the leading threat to wild condors in Utah and Arizona.
Courtship behavior by this year's potential parents was observed by biologists this winter. They've also shown nesting and incubating behaviors. A key one is the adults taking turns looking for food during two- to three-day stretches.
"The cavity is 1,000 feet above the canyon floor so no one has yet had direct observation of a chick. If the egg had not been viable, or if a hatchling had died, there would be no reason for the adult condor pair to continue to visit this cavity," said Eddie Feltes, Condor Project manager for The Peregrine Fund.
Visitors to Zion are often thrilled to catch sight of the big birds and have come to recognize some of the condors.
"The California condors have become a very charismatic species and have been captured in many vacation photos in our area's national parks," said Fred Armstrong, chief of Resource Management and Research at Zion National Park, in a statement. "Repeat visitors come to recognize them by their wing tag numbers and routinely ask about them. The park is excited to provide protected habitat for these magnificent birds and to play an important role in their recovery."
Lead poisoning through the ingestion of ammunition used by hunters in Utah and Arizona has been keeping condor numbers from growing despite excellent habitat.
But programs were developed in both states to provide incentives for hunters to swap to non-lead alternatives and it appears to be helping.
The Peregrine Fund announced in March that its annual testing of blood from condors living in northern Arizona and southern Utah showed the lowest lead levels in a decade.
"The ups and downs of lead poisoning over the years demonstrate that any single season does not make a trend, but our test results are encouraging," Feltes said in a statement.
Only 16 percent of the condors trapped and tested by researchers starting in September 2013 showed extreme exposure to lead in their blood. That's a big change from the 42 percent of condors that showed extreme exposure in 2012.
Biologists treated 11 condors this past winter with lead-reducing chelation therapy. In the winter of 2013, 28 condors had the same treatment.
Last fall Utah Division of Wildlife Resources officials added new incentives to reward hunters in the Zion unit, an area frequented by the rare birds. It runs from Interstate 15 on the west to Highway 89 on the east, State Road 14 on the north and to the Arizona state line on the south.
Hunters who showed up at area checkpoints with non-lead ammunition, or those who hauled out the entrails of animals they killed with lead ammunition, were entered in a drawing for an all-terrain vehicle or a new rifle.