Thom Lord— 25 February 2005 — in California Condor Restoration ShareGreetings, Notes from the Field readers! The winter months in Arizona have typically provided condor project biologists with a bit of “down time”—a period where the birds travel somewhat less, providing a brief respite from the 13-hour days of summer tracking and the bustling schedule of trapping and lead testing in autumn. This lull in activity, however, has become steadily shorter with each passing year of the project. As the condor population in Arizona grows, and as the birds spend an increasing amount of time away from the release site at Vermilion Cliffs, the condor crew is required to be on their toes and ready for anything nearly year-round. Thankfully, the stellar group of field biologists working on the project prove time and again that they are up to the challenge, as the eventful month of February demonstrated.
As you read in the last installment of Notes from the Field, wild-fledged Condor 342 (who we now know to be a male) was re-released into the wild in January after undergoing surgery at the Phoenix Zoo. The parents initially paid a reassuring amount of attention to their newly returned chick, but very soon after Condor 342 was released, his mother, Condor 149, seemed to lose interest completely, and has yet to feed or even visit the chick since the day of his release. The chick’s father, Condor 114, has been a different story altogether. He continued to be a model parent, feeding the chick religiously throughout the month. This was very helpful in helping us locate Condor 342, whose radio-transmitter failed soon after the bird was released. Condor 342 appears to have recovered completely from his ordeal, and took his first long flight on 8 February, soaring past the release site and roosting a few miles north of his nest cave. Meanwhile, Condor 114 does not seem to have any difficulty in caring for Condor 342 by himself, and has already been observed courting other females!
The other wild-fledged chick from last season, Condor 350, continues to impress us with its flying ability, showing up in a number of places surrounding its nest cave in the Grand Canyon. Both of Condor 350’s parents return regularly to GCNP to feed it, and we have no indication yet that the chick has left the park boundaries. Based on Condor 350’s facility with flight, though, that day seems to be approaching quickly, if it hasn’t already arrived. Condor 350 still hasn’t presented an opportunity for us to capture and tag it, so for now we have to be content to observe the chick at its leisure, either from the rim or by hiking into the canyon.
Although the continuing success of the wild-fledged chicks in February was encouraging, Arizona’s condor population recently took an unfortunate blow with the loss of two sub-adult condors. Condor 235 died in mid-January, and Condor 249 approximately two weeks later. The deaths were unexpected and at first perplexing, but due to the diligence of the field biologists observing the birds, each condor was collected within hours of dying and sent to the Pathology Lab at San Diego Wild Animal Park for necropsy. It was determined that the birds died of lead poisoning, both showing extremely high lead levels in the tissues, as well as having pellets of lead shot in their digestive tracts. This was made all the more frustrating by the fact that both birds had just been released after being treated for lead exposure from another source. After Condor 235’s death, we began to suspect that something was amiss with Condor 249, but our attempts to trap him proved unsuccessful. This was one of the first cases that we were able to observe behavioral signs of lead toxicity in a free-flying bird before it died; the poisoned birds we have been able to observe in the past have typically shown few obvious behavioral abnormalities right up to the time of death. This is a testament to the toughness of these birds, as is the fact that Condor 249 managed to elude our efforts to capture him until he died.
Needless to say, after the deaths of two condors in such a short period of time, the crew was on high alert for any signs of problems with other birds. On 3 February, Peregrine Fund biologist Eddie Feltes observed Condor 246 exhibiting odd behavior, similar to the behavior that Condor 249 displayed shortly before he died. We set up to trap immediately, and were able to capture Condor 246 the next morning. Luckily, his blood lead levels were well within the “safe” range, but he had an unidentified mass near his breast. Project Director Chris Parish immediately transported him to the Phoenix Zoo to have him checked and treated. The mass turned out to be an infection, most likely from a puncture wound. Dr. Kathy Orr performed surgery on Condor 246 and treated him until 21 February, and he was back in the wild two days later. We owe Dr. Orr and the Phoenix Zoo a great deal of gratitude for their continuing assistance to the project. Thankfully, this would be the last scare that we would have this month.
Although the loss of Condors 235 and 249 was disheartening, the rest of the population continued to provide us with reason for excitement throughout February. The breeding season fell into full swing, with numerous courtship displays and at least two pairs of breeding-age birds showing nest-searching behavior. We’re keeping our fingers crossed that Condors 133 and 158 (female and male, respectively), as well as Condors 136 and 187 (also female and male, respectively), will be able to produce wild chicks this year. Condors 123 and 127, the pair that produced wild-fledged chick 305 in 2003, should also be ready to breed again this season. In addition to the fairly well-established pairs, there are a number of other breeding-age birds who could surprise us. Here’s hoping…
Finally, Arizona’s condor population gained a few new members in February. On 4 February, we released Condors 297, 302, and 314, the final members of the cohort hatched in 2003. In mid-February, a group of Peregrine Fund biologists traveled to the Pinnacles National Monument release site in central California to transfer three condors—Condors 266, 270, and 287—to the flight pen in Vermilion Cliffs, Arizona. These birds had been observed perching on power poles in the area surrounding Pinnacles, a potentially dangerous behavior that biologists at the Pinnacles site did not want to be transmitted to the rest of the population. Because there is less potential for such behavior near the Vermilion Cliffs site, it was decided that the birds would be re-released in Arizona. These three are currently being held in the flight pen, and should be released shortly. We also placed tags and transmitters on five more birds from the 2004 cohort for release on 1 March, who, when released, bring Arizona’s free-flying condor population up to 54 birds! Until next time…
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