A review of the 2007-2011 period of the California condor reintroduction program in northern Arizona and southern Utah is complete. A team of wildlife officials, land managers and condor biologists point to a number of successes; including an increase in the free-ranging population, consistent use of seasonal ranges by condors and an increased number of breeding pairs.
The experimental Southwest condor reintroduction project began with the release of six condors at the Vermilion Cliffs in Arizona in December 1996. This is the third 5-year review of the program.
At the end of 2011 there were 73 free-ranging condors in the Southwest population – an increase of 16 birds during the review period (there are presently 76). A total of 41 captive-raised birds were released into the population. Ten chicks were wild-hatched during the 5-year period, and 7 of them died or went missing. An additional 24 adults died or went missing, and 5 birds were returned to captivity.
During the first 10 years of the recovery program, most birds stayed in the general vicinity of the Vermillion Cliffs release site or concentrated along the Colorado River corridor. During this review period, many birds in the population have been spending a greater portion of the year in Utah, using areas near Zion National Park along the Kolob Terrace and the high country of southern Utah.
As the wild population has matured, there has been increased breeding activity, with 5-6 pairs attempting to breed each year from 2007-2011 and 1-3 chicks successfully produced each year – all in Arizona.
Lead poisoning remains the primary diagnosed cause of mortality in the population. Lead poisoning cases occur predominantly in the fall and winter months and are associated with the big game hunting seasons, but sporadic incidents have occurred in the spring and summer. The Peregrine Fund’s field team attempts to trap every individual in the free-flying population before and after the hunting season, but as the population has grown and is using a larger range, this has become more difficult. Between 85%-97% of the population was tested for lead exposure each year of this reporting period, with 27%-56% of those tested treated (chelated) for lead poisoning.
Since 2005, Arizona Game and Fish Department (AGFD) has conducted a voluntary lead reduction program, with 83%-90% of successful Kaibab area hunters participating in 2007-2011. Utah Division of Wildlife Resources (UDWR) initiated a voluntary non-lead ammunition program for the Zion Wildlife Management Unit in southern Utah in 2010 but estimates only 5% participation among these hunters. The number of Utah hunters who are involved in the program is expected to increase, however, as the UDWR expands its non-lead ammunition program in 2012.