The US Fish & Wildlife Service is happy to announce the successful end of the 2007 breeding season in the Southern California condor population. The fourth and final California condor chick, No. 449 (aka WC17), fledged on Thursday, Dec. 6. This flight was a distance of 25 meters and was 15 seconds in duration. The bird was 208 days old at time she fledged. The California population produced four chicks this season, condors No. 428 (WC13), 443 (WC15), 449 (WC17) and 450 (WC18), all of which fledged. Currently, fledgling survivorship is 75 percent. Unfortunately, condor No. 443 died shortly following the October 2007 Ranch Fire. All chicks this season are females and are being monitored via radio telemetry and visual observation. We are still keeping track of chick/parent interactions and their movements as they move away from their natal sites.

It was a productive year for California. The breeding effort for the season was 36 percent out of 21 adults that are six years of age or older. Southern California had eight pairings involved in courtship behavior at the start of the 2007 season. Four of these pairs produced nests. One pair that did not nest had attempted to nest the year prior, condors No. 98 and No. 112. It is unknown why this pair failed to produce an egg though it might relate to the previous mate, condor 216, competing for the male’s attention. A second pair that was observed in courtship that failed to nest was condors 237 and 214 that were successful in 2006. A combination of lead treatment and post fledgling care likely prevented their 2007 attempt. The final two non-nesting pairs both involved males that just turned six years old this season. In 2007, one of the four pairs to nest was a first time pairing, condors 206 and 255. No. 125 and No. 111 were involved in their fourth nesting attempt in the wild, returning from their period at the San Diego Zoo’s Wild Animal Park where they produced condor 417. Condor No. 21 (AC9) and No. 192 also made their fourth attempt this year. Condor 107 and 161 nested for the third time.

Egg fertility was 75 percent. The egg laid by No. 111 was infertile. Transplanting a viable egg from the Wild Animal Park prevented nest failure. The nest history for condors 21 and 192 indicated questionable egg viability with only 33 percent hatching success. We therefore preemptively transplanted this pair’s egg as a means to determine egg health. The first egg used to substitute the dummy egg that this pair incubated failed to hatch due to malposition. The pair’s original egg was then used as the second replacement egg, which hatched successfully. During the egg stage, there were seven entries performed on the nests. One was for a fertility check of the first time pair’s egg and all others were while performing aforementioned egg transplants. Only a single micro-trash item was recovered from the five nests that were entered during the egg stage. One nest (condors 107 and 161) was not entered during the egg stage because of the 100 percent hatching success observed during their previous two attempts.

Joseph Brandt will continue this story with specific information on how each chick hatched in 2007 faired in part two of this blog. Stay tuned for 2007 California Condor Breeding Season - The Chick Phase

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