Establish a self-sustaining population of California Condors in the Grand Canyon/Arizona Strip regions of northern Arizona and southern Utah in cooperation with state and federal agencies, tribes, local communities, and the private sector.
California Condors are highly endangered. Only 22 individuals remained alive in 1982. Since 1996, The Peregrine Fund has produced condors at its captive breeding facility at the World Center for Birds of Prey in Idaho and released them in Arizona as a “non-essential experimental population” under a Memoranda of Understanding and applicable special permits with the U.S. Fish and Wildlife Service, National Park Service, Arizona Game and Fish Department, and others.
Non-invasive research into captive breeding and restoration increases the body of knowledge regarding condor conservation and natural science, and provides the basis for ongoing management decisions. Specific topics of field study include condor movements, behavior, foraging ecology, and toxicology, specifically lead poisoning. Findings and publications arising from these investigations provide guidance to this and other endangered species restoration programs through scientific exchange and publication.
Since 1996, The Peregrine Fund has released 162 condors, documented 25 wild-hatched young and102 fatalities (56 diagnosed, 42 missing or unknown), and returned 10 individuals to captivity permanently and one in temporary holding. We monitor daily movements and behavior of more than 70 individuals in the wilds of northern Arizona and southern Utah. Captive breeding, release, radio-tracking, and adaptive management has brought the total world population to more than 400.
In 2014, an adult pair produced a chick in Utah for the first time since reintroduction began in Arizona in 1996. The chick's existence was visually confirmed, but the adults' behavior a few months later led our biologists to believe the chick had died. A carcass was not recovered.
A fair proportion of the wild population in Arizona and Utah has reached breeding age and has produced 25 young in the wilds of the Grand Canyon, Vermilion Cliffs National Monument, Kaibab National Forest and Glenn Canyon Recreation Area, all in northern Arizona, and Zion National Park in southern Utah. We have documented breeding behavior in wild-hatched condors in Arizona and confirmed the first successful condor chick produced by Arizona wild-hatched condors, marking the beginning of an F2 population.
The condor flock forages largely on its own. We have identified lead poisoning as the principle mortality agent, its source, and advancements in reducing its prevalence and impact. The management agencies responsible for the harvest of game in Arizona and Utah have initiated mitigating efforts to reduce the amount of lead available to scavengers. With continued effort and progress towards reducing lead in the landscape, we are confident that the condor population has the potential to eventually thrive, reaching the recovery goal of 150 individuals and 15 breeding pairs. Continued efforts to encourage the use of non-lead alternatives for dispatching animals, wild or domestic, is key to this recovery effort.
The Peregrine Fund has a captive flock of more than 50 condors at its breeding facility at the World Center for Birds of Prey in Idaho. There are 18 breeding pairs, which produce about 20 eggs, plus two display birds and a mentor adult bird for juveniles. Most eggs hatch in Idaho; others are transferred to other breeding facilities to be placed in wild nests and enhance genetic diversity. All chicks hatched at our facility are parent-reared or foster-reared. Each year, about a dozen juvenile condors are transferred to the Vermilion Cliffs Release Site in Arizona.
Prior to release, candidates are housed in a 60x40-foot flight pen where they are monitored and evaluated before being deemed fit for release. Before release, each condor is fitted with patagial (wing-mounted) number tags and a pair of patagially-mounted, sometimes retrix-mounted, radio transmitters produced by Advanced Telemetry Systems, Holohill Systems, Microwave Telemetry, or Merlin Systems. The transmitters were either conventional Very High Frequency (VHF) or Global Positioning System (GPS/PTT) instruments.
Monitoring of Population
Our reduced staff of five biologists and field manager tracked daily movements of condors within the 10(j) area and recorded activities of condors throughout the reporting period, a task made more difficult by the increasing numbers of free-ranging birds and their widening tendencies toward long-range movement in this rugged region of sometimes limited access. We continue, therefore, to benefit from satellite-reporting PTT/GPS transmitters (Microwave Telemetry, Inc.) deployed on select condors.
We continue to provide contaminant-free food at the release site every three to four days for two main purposes:
Most of the condors in the AZ/UT flock return to the release site during breeding season and the added lure of available carrion offers an opportunity to trap them to replace transmitters and assess lead burden. Condors with high blood-lead levels can then be transported to our treatment facility fwhen necessary.
To increase the precision and breadth of our knowledge of condor foraging relative to lead poisoning, we asked our partners for increased support to purchase additional GPS transmitters. We were able to deploy an additional 20 GPS transmitters, which should demonstrate varying rates of use within the two states and relate acquired blood lead levels to those areas of use, a valuable source of feedback to the management agencies. In addition, the field team collected roost relocation data to fill in the gaps of known locations of individuals by ground-truthing previously observed and recorded patterns of habitat use.
We are documenting what has become the normal trend of extended use of Utah, the northern end of the condor’s general range. Analysis of GIS relocation data relative to measured blood-lead levels in the future should reveal valuable information that can be used to inform policy in these regions.
Close monitoring of movements has also aided us in quickly averting behavioral problems that still occasionally develop among inexperienced condors. Additionally, we continue our public education and outreach efforts in areas where condors and humans overlap.
Since 1996, we have identified 104 confirmed or assumed deaths. Fifty four percent of cases have been diagnosed by necropsy performed by the San Diego Zoo’s pathology department or the U.S. Fish and Wildlife Service’s forensics laboratory. Lead poisoning accounts for 51.8% of diagnosed deaths, followed by 28.6% of cases attributed to predation by either Golden Eagle or coyote. The third and fourth leading causes of diagnosed death are starvation and shootings at 5.4%, respectively. Nearly half of all documented or assumed deaths are cases where condors have either disappeared (missing and assumed dead) or those whose remains were too degraded to determine cause of death.
We intensely monitor newly released condors and aggressively haze them from unsafe roosts to decrease predation by coyotes, the number one predation threat to young and inexperienced condors.
Although condors have gone missing in years past, we always hope they will one day revisit the release area, just as Condor 176 reappeared after being out of contact for nearly five months. However, we recently added seven condors to the “missing and/or unknown” category, which now totals 42 individuals.
Reproduction in Arizona and Utah
As many as 12 condor pairs were documented in 2014; three pairs were tending young from the previous year, and four pairs produced eggs. Four females produced a total of six eggs (two females recycled), and three chicks were confirmed. One chick later died. A total of 25 condor chicks have been confirmed since 2003
Our research continues to include observations of lead pellets and fragments in the digestive tracts of lead-poisoned condors, consistent with previously discovered bullet fragments in rifle-killed deer and coyotes fed on by condors. Radiographs of the remains of deer killed with standard lead-based rifle bullets have revealed numerous metal fragments as the normal condition.
The Peregrine Fund continues to focus on lead exposure detection and treatment as the essential element in maintaining the population. Since 2000, we have trapped, obtained blood for lead-level analysis, and treated sickened condors when necessary.
We have found an abrupt increase of blood lead-levels corresponding with increased use of deer hunting areas on the Kaibab Plateau and the Kolob range in southern Utah during the weeks prior to testing. The period of highest exposure is October and November when the deer hunting seasons are underway, and the period of greatest lead-caused mortality among condors is December and January, reflecting the latency of effect.
We collected blood samples (including re-samples) from 96% of the wild population, which yielded slightly higher levels than previous years and 28 individuals were treated for lead poisoning with chelation therapy. Each individual case of lead exposure is independently diagnosed and is based not only on blood-lead level, but on body condition, frequency of previous known exposures, nesting activity, and other variables.
|Project History||Notes From The Field|
|Publications and Data||Other Information|
|Photos and Videos|
|Detailed information on released condors||California Condor current population data table|
|Condor Cliffs page on Facebook||AZGFD: California Condor Recovery|
Southwestern United States, with a focus on the Grand Canyon area of Arizona