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About Author: Michael Wallace

Posts by Michael Wallace

5

Phantom Condor Chick Appears

A young, unmarked California condor soars in the skies of Baja California, Mexico.

A young, unmarked California condor soars in the skies of Baja California, Mexico. Photo credit: Juan Vargas

In the spring of 2012, our newest wild California condor pair in Baja California, Mexico, identified as #361 and #373, continued to show signs that they were incubating an egg by being more aggressive to the other condors around the feeding site and by spending a lot of time in a remote area dotted by deep canyons and precipitous cliffs. Their GPS wing transmitters indicated a near-exact position of where the nest would be out in the wilderness by latitude and longitude readings. Plugging these coordinates into our handheld GPS, Program Field Manager Juan Vargas and I struck out in September 2012 to try to find the nest, knowing that it was about 15 miles (24 kilometers) out to the remote south of our condor field station.

We traveled light and fast but only made it three quarters of the way there after three days through rough terrain and vegetation. With dwindling food and clean water, we decided to head back. Also, the GPS maps indicated that the nest was very high in precipitous terrain, and we were not carrying sufficient ropes and equipment to deal with it safely. Within condor release programs in the United States, if the nests are too difficult to find or ascend to, scientists rely on waiting for the young to fledge and show up at feeding sites, where they can be trapped and tagged later. We decided to do the same, since verifying the young at the nest would be too costly in terms of helicopter time, which would be the only way we could safely access it.

The chick and its mother, #???

The chick and its tagged mother at rest.

The downside to this decision was that the chick would not be inoculated for West Nile virus and would run the risk of catching the disease if we could not administer the vaccine. From our field station, Catalina Porras and crew analyzed both radiotelemetry and GPS data and estimated that the chick probably fledged in October. Over the three months that followed, only the behavior of the parents at the feeding site and their movement patterns continued to give us hope that there was indeed a chick flying around in the backcountry. We continued to scan the skies for a “tagless” condor with a gray head.

Finally, on February 4, 2013, Juan and a crew member observed a juvenile condor showing behavior that stood out from the others. Further scrutiny revealed that the black-headed youngster had no tags. It was hard to keep the excitement contained as we realized that the phantom chick had survived! As the new chick becomes accustomed to the other wild condors and the feeding site over the next few months, we are hoping to trap it, administer the West Nile virus vaccine, and tag it with GPS transmitters so we can safely follow its progress.Three condor pairs are looking like they may produce young this season. With luck, we may find more dark-headed condor young in the skies over the Baja mountains next year as well.

Michael Wallace is a conservation program manager for the San Diego Zoo Institute for Conservation Research. Read his previous post, Releasing Condors: Not So Easy.

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Releasing Condors: Not So Easy

California condor #430 in the chaparrel.

California condor #430 in the chaparrel.

On Friday, September 18, we attempted to release three more California condors to the wild at our condor reintroduction site in Baja California, Mexico. We had conditioned the three new birds, numbers 430, 436, and 446, in the large aviary with our adult mentor, Xewe, since they arrived at the site from the Wild Animal Park on March 19. The threesome was transferred a few weeks ago to the release pen situated atop a 2,000-foot ridge, where they could become accustomed to the sights and sounds of the area and see previously released condors use the food and water available to them once they were free. New tags and transmitters were attached on the night of September 13 by the field crew and they were ready to go. However…

Condor #446 in the release pen.

Condor #446 in the release pen.

This simple scenario is overshadowed by the reality that older condors in the free-flying group have worked out their social status differences, for the most part, and any newcomers must go through an initiation that can be rough, or at least intimidating. So, after opening the 6-foot pen door at 3:30 a.m. on September 17, one of the mid-level, older birds, #362, entered the pen when there was enough light and began harassing #430, driving him out of the pen.
The older condors roost on top of the release pen.

The older condors roost on top of the release pen.

With sort of a forced release, he flew to a hillside a hundred or so yards to the south and began to climb. From a higher vantage point, he was soon able to fly back to the vicinity of the release pen but not without drawing the attention of other older birds that took turns approaching and investigating him up close.

Condor #436 on release day.

Condor #436 on release day.

After all the attention (at times there were seven condors playing on the release aviary roof netting), one of the release birds, #446, remained in the pen overnight, one slept in the tall pines toward the cliff, and one, #436, roosted overnight on top of the pen. Over the next few days all seemed to settle in a more normal release routine, with the newcomers taking short exploratory flights and tentatively feeding in and around the established birds at carrion we strategically placed out under the cover of darkness.

Now we hope for a smooth transition over time as they practice flying, learn where to find food, water, roosts, and seek acceptance within the group.

Mike Wallace is a conservation program manager for the San Diego Zoo.

California Condor Recovery Program

4

Baja Condor Chick Update

California condor chick in Baja California, Mexico

California condor chick in Baja California, Mexico

With enough rope to make the 550-foot (170-meter) rappel to the cliff base, Juan Vargas and I moved steadily downward to this year’s only condor nest in the Baja California, Mexico, California condor release program (see post, Condors: Quest for the Egg). Situated in a 6-foot (1.8-meter)-deep cave punched into a massive granite wall, it was the same cavity this pair attempted to nest in last year but failed in the egg stage of incubation. This season they incubated an egg successfully, and the cave now housed a startled, month-and-a-half-old chick that began hissing and lunging at us as we landed at the cave opening.

Mike and Juan rappel to the nest site.

Mike and Juan rappel to the nest site.

From a settled sitting position in the cave entrance, I scooped the chick into my lap during one of its attacks to examine its crop for signs of microtrash ingestion, a problem seen in some of our wild condor chicks in the U.S. I palpated one hard lump up to its mouth and could see that it was bone and a healthy part of its diet.

Mike and chick eye each other.

Mike and chick eye each other.

Besides checking for general health and feather growth, we were there to administer a one-time dose of vaccine to protect the chick against West Nile virus. An experimental DNA vaccine developed by the CDC (Centers for Disease Control and Prevention) specifically for condors, it has proven 100-percent effective in guarding our captive and wild birds against the virus. One dose usually protects the condor for life.

We check the blood some time later and can administer another dose, but usually it is not needed. Kiliwa, as we are calling him/her after the Native American tribe in the northern Baja California area, is one of 15 condor chicks sitting in nest caves throughout the range where condors have been introduced in California, Arizona, and Mexico. Including all zoo production, an amazing total of 49 condor chicks have hatched this year!

Mike Wallace is a conservation program manager for the San Diego Zoo’s Institute for Conservation Research.