Tuesday, October 21, 2003

AC8, AC9 and the last days of wild California condors by Jan Hamber and Bronwyn Davey, 2003

On a spring day in May 1982, in a remote cave atop a cliff in the Sespe Condor Sanctuary, southern California, a tiny pink California condor chick pecked its way out of its hard egg shell that had protected it for nearly two months. He was greeted by his mother, a giant black bird, with a mottled orange head and a wing span of over 9 feet, who gently stroked him with her powerful beak and nestled him close under her warm body.

This same scene had been repeated for tens of thousands of years. However, after less than 200 years of direct contact with Europeans, this scene was about to end. The mother and chick were part of a species that without drastic measures would cease to exist forever. The California condor population had experienced significant declines for decades and less than 26 California condors remained in the world.

Neither the chick nor its mother were aware of how significant this event was for their species or how critical a part that each would play in efforts to save their kind from extinction. The chick, later named Xolxol (ho-ho), was captured as a chick in 1982 and became the first addition to the captive breeding program. This event marked the beginning of the California Condor Recovery Program. The mother, later known as Adult Condor #8 (AC8), was the last free flying wild female California condor captured for the recovery program.

After the capture of Xolxol, AC8 continued to nest successfully in the wild, with her unnamed partner. In 1983 and 1984 she laid several eggs, which were removed and now form a significant part of the captive breeding program at San Diego Wild Animal Park and Los Angeles Zoo. By late 1984 the numbers of wild California condors had dropped by nearly half. AC8 together with her partner was one of only 5 actively breeding pairs in a total population of 15 wild birds. Tragically, in November 1984, AC8’s partner disappeared and never returned. Although this was a serious set back for the condor program, biologists were still optimistic that California condors from the captive breeding program could still be released back into the wild where a wild condor population existed. The other wild pairs were breeding successfully and 14 eggs and chicks had already been produced to form the nucleus of the captive breeding population.

Jan Hamber, a condor biologist working on the program at the time recalls “all we needed was just one more successful breeding season and 1986 would then have been the year that young birds could be released from the captive group and used to augment the wild population”.

It appeared that the recovery plan was working and success was just around the corner. But it was not to be. As the biologists fanned out into the nesting areas in late January 1985, reports came filtering back that either one or both members of pairs were missing from the breeding territories. By April, when the missing mate of a new pair was found dead from lead poisoning on a ranch in the Sierra, it was clear that some disaster had struck. Six condors were missing from the population. Only 9 birds survived, and worse yet, only one pair remained to breed: the Santa Barbara pair known as AC2 and AC3.

The bottom had dropped out of their plans and the program entered a phase of acrimonious debate as to whether to take all the remaining 9 birds into captivity or leave some out to keep the wild population going. The battle raged during the remainder of 1985 and three birds were removed during the summer and fall until only 6 were left, 2 females: AC3 and AC8 and the rest males: AC2, AC5, AC6, and AC9.

Then in mid-December 1985 disaster struck again. It was reported that AC3 was down on Hudson Ranch. It was obvious that she was sick. She was finally captured on January 3rd. Despite constant care and treatment at San Diego Zoo, AC3 died January 18, 1986, another victim of lead poisoning. Now no breeding pairs remained in the wild and only one female, AC8, was left with four males. The remaining adult males, whose partners had also disappeared, desperately tried to court AC8. However, she was uninterested and instead chose AC9 , a young male just coming into adulthood.

AC8’s breeding experience over AC9’s was obvious. She accepted his advances and immediately began inspecting various caves for a suitable nest site, with AC9 in pursuit. She eventually found one and together with AC9 produced 2 eggs. Their first egg was found to be so thin-shelled that it was crushed - a casualty of DDT. The second egg survived and was taken to the San Diego Wild Animal Park to be incubated and hatched.

With only 5 remaining wild birds, only one breeding pair and the ever present threat of potential death, 2 more condors were captured. First AC6 on April 20, 1986 and then AC8, on June 5, 1986. Now only AC2, AC5 and AC9, all males, remained.

Eventually the call came to take into captivity all the remaining 3 condors. AC2 was the first to go on December 13, 1986. You can imagine how condor biologist Jan Hamber felt as AC2 was captured, a male that she had watched, along with his now dead partner AC3, for 11 years at 11 nest sites. AC5 was next and was caught under a cannon net on February 27, 1987 in the late afternoon. For trapper, Pete Bloom, it was a moment never to be forgotten. As he placed AC5 in the sky kennel for the trip to the zoo, he noticed AC9 watching him. The last wild California condor in the world was perched in a large oak tree above the trap site, his body silhouetted against the setting sun.

And then came the fateful Easter Sunday when AC9 was captured. For the first time in tens of thousands of years there were no California condors soaring in the sunny skies of southern California. All 27 living birds were in captivity. At the time, it seemed that it was the end of the road for the wild population. All those involved in the program felt a pervasive sadness. Would these majestic birds of the sky ever soar again?

After their capture, AC8 and AC9 were separated and partnered with other condors to maximize the genetic diversity within the captive population. Both AC8 and AC9 are parents and grandparents to many of the young condors which have been released into the wild. AC8 is considered a genetic “founder bird” and is one of the oldest condors left. Her exact age is unknown, however, she is at least 26 years of age, but probably much older (ie. over 40).

Finally, on April 4, 2000, 14 years after her capture, AC8 was released and once again soared over her home territory in the Sespe Condor Sanctuary near the town of Fillmore in Ventura County, CA. She was the first wild born condor to be released back into the wild and it was the first time that a wild born California condor had flown free for almost 13 years. Two years later on May 1, 2002, AC9 the last wild California condor captured for the recovery program, was released after 15 years in captivity. AC9 was AC8’s last mate in the wild. AC8 had not successfully bred in captivity since 1995 and she is believed to be past her breeding age. AC9 is 22 years old and his genetics are well represented in the condor population.

Including AC8 and AC9, only nine original wild California condors are left. These precious nine hold the last of the wild knowledge that has been passed down through generations of wild California condors. It is hoped that with the release of original wild birds they will act as a mentors for the captive bred free flying condors and may provide them with additional skills for survival in the wild. It also gives them an opportunity to live out the rest of their life flying free. Three juvenile condors, approximately 12 months old, were also released on May 1, 2002. One of these juveniles is from an egg laid in the wild last year in the Santa Barbara back country. This chick was raised by AC9 in the Los Angeles Zoo. The juveniles spent several months in a flight pen at Hopper Mountain National Wildlife Refuge with AC9 and other adult birds. The young condors were placed into the flight pen with the adult birds to gain experience competing for food and to form social bonds prior to release. While in the flight pen, the birds undergo power pole aversion training to help them avoid deadly encounters with power poles once released. AC9 and the younger birds were transported to a holding facility at the Sespe Condor Sanctuary approximately one week before their release to give them time to acclimate themselves to their new surroundings. Since release AC9 has re-visited some of his old roosting sites and has integrated well into the captive bred population. So far AC8 and AC9 do not appear to have rekindled their former relationship.

AC8 was shot and killed in February 2003.

Written by Jan Hamber and Bronwyn Davey