Establish self-sustaining wild populations of California Condors through captive propagation, release, and management with the ultimate goal of removing the species from the Endangered Species List.
Since 1996, we have worked with state and federal agencies, tribes, local communities, and private partners to establish a self-sustaining population of California Condors in Arizona and Utah.
We produce condors in captivity at our World Center for Birds of Prey and release them to the wild at Vermilion Cliffs National Monument north of the Grand Canyon. Some of the eggs and birds produced in Idaho are exchanged with other facilities to ensure maximum genetic diversity in the total population, which now numbers more than 400 birds.
The condor population has grown substantially since 1982 when only 22 of the huge birds remained on Earth. This success is due to captive breeding, release, radio-tracking, and adaptive management. Our daily monitoring and published data have contributed significantly to the scientific knowledge related to this iconic species.
Lead poisoning continues to be the leading cause of diagnosed death in condors and the primary obstacle to condor recovery. Our research provides solid evidence about the source of lead and ways to reduce its impact. We are working with game management agencies in Arizona and Utah to limit the chances that condors will consume small fragments of lead in the carcasses and gut piles of deer and other shot animals.
We believe that voluntary action by hunters and others is the best way to overcome this problem. Awareness and education are our best tools for building a wider understanding of what has long been a hidden threat to wildlife. With less lead in the landscape, we are confident that condors will thrive in the wild once again.
Of 59 captive California Condors in Boise, 40 are adults: 18 breeding pairs, three Condor Cliffs display birds, and a mentor bird for juveniles. In addition, there are four juveniles from the 2009-2011 breeding seasons and 15 chicks hatched in 2012. Of the four juveniles, two are being held for the captive breeding program and two are being held for release in California and Arizona in 2013. Ten juvenile condors reared in Boise, five juveniles reared in Oregon, and one adult condor were transferred from our facility to field sites in California and Arizona and to breeding and display facilities at Los Angeles Zoo, Santa Barbara Zoo, and San Diego Zoo Safari Park.
Eighteen female condors produced 22 eggs with 21 fertile. Of the fertile eggs, 15 stayed in Boise, four were sent to the Los Angeles Zoo to be placed in wild nests in central and southern California, and two were sent to the Oregon Zoo to assist in successful pair bonding. Seventeen of the 21 fertile eggs hatched successfully. In exchange, three fertile eggs were transferred to Boise from the Los Angeles Zoo and all hatched successfully, bringing the total number of chicks reared in Boise to 15.
We successfully double-clutched two of our most genetically valuable pairs and two additional pairs to replace infertile and early dead eggs. In Boise, we had 95.5% fertility, 83.3% hatchability, and 100% chick survival. Of all eggs produced in Boise, we had 95.5% fertility, 81.0% hatchability, and 100% chick survival. All 15 chicks hatched at this facility were parent-reared. One chick in Boise has been reared from four days of age by a single adult female after her mate was removed for aggressively attacking her while in the nest box with the chick.
As they have since 2003, the adult condors in Boise were vaccinated against West Nile virus. We began trapping all condors that had not received a vaccine booster within the last two years and administered the Merial Recombitek Equine West Nile Virus Vaccine. We plan to continue to vaccinate the adults annually.
In accordance with the protocol established in 2009, each condor chick was vaccinated at 30 days of age, given a booster at 60 days of age, and blood was drawn for titer testing between 90 and 120 days of age. An additional booster was administered immediately after the blood sample was obtained between 90 and 120 days of age.
We depleted our supply of DNA plasmid West Nile Virus vaccine that was formulated by the Center for Disease Control and had to be stored in super-cold storage at the biology department on the campus of Boise State University. We will vaccinate and booster all condor chicks with the Merial Recombitek Equine West Nile Virus Vaccine from this point forward. Also, an aggressive mosquito abatement program continues to be maintained at the Boise facility.
A few changes were made to improve the facility and behavior of the condors. All existing condor breeding chambers were repaired to secure the chain link to the framework at ground level where time and erosion had exposed holes and pathways for skunks and badgers to enter chambers. Continued work was done with the addition of a 10,000-gallon-capacity pump on the large pool in the socialization pen that was installed two years ago that is changed and cleaned remotely from inside of the barn.
New cameras and a DVR were purchased to be installed in the socialization pen but installation had to be postponed due to the need to hold back two condors that will be released in 2013. We continued the process of improving and repairing the video and camera equipment used to observe the condors in the breeding chambers. New cameras and DVRs were purchased and installed in the Condor Cliffs display and the breeding chambers.
The Condor Cliffs display was renovated to add an opening and tunnel for the condors in the “cliff” wall to enter a trap/holding/feeding room created in the existing building attached to the display. Perching, substrate, heat panels, and a trap door were added to the room.
A 10 kW air-cooled propane generator with automatic transfer switch, heat pack, and 120-gallon propane tank was installed at the condor incubation facility. The generator turns on and powers the incubation facility automatically after a power outage and has enough kW to operate and maintain the proper heat and humidity of all condor egg incubators and chick brooders in use.
An Ecolab Energy Star sanitizing dishwasher was purchased and installed in the incubation facility to improve incubation sanitization and save an estimated 695 gallons of water during the incubation period. Another improvement to our incubation facility was the purchase and use of a UV sterilization lamp and wand to replace annual incubator fumigation. In addition, ongoing repairs were made to leaking and damaged pipes in the existing monitored fire protection sprinkler systems in the breeding barns.
We transferred six captive-bred condors (three females and three males) to the flight pen at the Vermilion Cliffs release site. All were from the 2011 cohort. There were 81 condors free-flying in Arizona.
Prior to release, candidates were housed in a 60-by-40-foot flight pen where they were monitored and evaluated before being deemed fit for release. Approximately two weeks before release, each condor was 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. In all, we released 16 condors during the reporting period, the largest number of birds released in a single fiscal year.
We continued to provide contaminant-free food on the average of every three days at the release site in the form of dairy calf carcasses. We intensely monitored newly released condors and aggressively hazed them away from unsafe roosts in an attempt to avoid predation by coyotes. Despite our efforts, we observed three deaths from predation (two coyote and one eagle).
Although condors have gone missing in the past, we always hope they will one day return, just as Condor 176 reappeared after being out of contact for nearly five months. This year, however, we added two wild-hatched condors to the “missing and/or unknown” category, which now totals 24 individuals. The ever-increasing independence and utilization of habitats in Utah by the condor flock, combined with the large amounts of inaccessible private property, continue to increase difficulty in tracking and monitoring condor behavior there. We therefore rely on our increased knowledge from our years of study and adaptive management.
Twelve pairs were observed: two were tending young from the previous year and 10 exhibited breeding behavior. Three of the latter were confirmed incubating within their respective nest caves and were later confirmed to contain viable young. In all, we have observed 18 wild-hatched young since 2003.
Monitoring of population
Our biologists and field workers tracked the daily movements and activities of condors, 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 limited access. We continue, therefore, to benefit from satellite-reporting PTT/GPS transmitters (Microwave Technology) on selected condors. These transmitters record hourly position fixes to within roughly 50 meters of the actual locations and transfer accumulated data each day to orbital satellite arrays. The technology was especially useful in the case of increasingly self-sufficient condors that failed to regularly return to the release site, as is now the case for many.
Six individuals wore PTT/GPS transmitters; we selected these condors on the basis of their representation of flock movement or other considerations important to management. We were able to map entire sequences of movement by GPS-equipped condors; for example, when pairs were forming or later prospecting for nest caves, or when they made incubation exchanges. The transmitters were especially valuable in revealing locations of condor concentration and prolonged activity in canyon regions that were difficult for us to access and remote private lands of southwestern Utah. We used the transmitters to locate areas of foraging, especially in connection with lead exposure.
We continued to see what has become the normal trend of extended use of Utah, the northern end of the condor’s home range. Most of the birds eventually returned from the hills just outside Zion National Park to the release site as the winter snows made carrion more scarce. This period is characterized by an increasing use of the Kaibab and Paria plateaus where condors have continued to encounter lead bullet fragments in the remains of shot deer, coyotes, and marmots. GPS transmitters have been especially valuable in revealing the exact locations of condor activity both in real time and in retrospect.
Close monitoring of movements also aided us in quickly averting behavioral problems that still occasionally develop among inexperienced condors. We continued to condition them by hazing, installing aversive conditioning devices in highly used areas when necessary, and confinement for extreme cases. These measures are intended to break patterns of undesirable behavior in relation to humans and artificial structures. Our records show that such conditioning results in improved behavior as the birds mature. We continued our public education and outreach efforts in areas where condors and humans overlap.
|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