— 9 July 2008
— in California Condor Restoration
Greetings NFTF readers! June has been a fairly standard month as far as condor activity goes during the summer. The wild flock is covering immense distances as the birds forage daily for new carrion carcasses that dot the landscape of condor country. To date, our total number of birds tracked in the Kolob region of southwestern Utah has topped 31 birds, which is about average for this time of year. This region will see an increasing amount of birds roosting and foraging there as the summer months progress. GPS tracking, as well as conventional telemetry tracking by biologists on the ground has led our crew to several carcass locations that the flock has been feeding on, mainly domestic sheep in Utah, and mule deer on the Kaibab Plateau in Arizona.
The maze of red-wall canyons that provide ideal
nesting locations for the condors in the Grand Canyon area.
GPS tracking data on Condor 280 (part of the mystery pair of the Grand Canyon) has also revealed a routine travel pattern of foraging in Utah, then making the 80+ mile trip back to the assumed Grand Canyon nest site shared with Condor 234. Condor 280 has, over the past few years, been a regular in the Kolob region of Utah. She would usually make the trip north early in the summer, then not return until the snow falls in early winter. But now that she has set up a breeding territory with Condor 234 in the Grand Canyon, her pattern of travel has changed. She is always included in each group of birds that have located a “local” carcass (Grand Canyon or Kaibab Plateau in AZ), but when the food gets scarce down here, she seems to automatically make the trip up to Utah where she knows there is a constant supply of carrion, and then high tail it back down south to her nesting territory to feed the assumed chick deep in the canyon interior. This pattern of forage and travel gives us every indication that the nesting situation is still active and healthy, despite not yet locating the actual nest cave location or any visuals on a chick. We have, however, been able to catch occasional glimpses from the south rim of Grand Canyon National Park of the pair soaring in the canyon that we believe houses the nest cave, but still have not yet pin-pointed the exact cave.
The other two nest cave locations in the Grand Canyon, those of pair 127F/123M and 133F/187M, we believe are still active and being tended to by both adults of each pair. At the time of writing, crew member Matt Podolsky is headed into the Grand Canyon to observe the Salt Creek nest cave of 127F/123M to get some more descript visuals on activity, since that cave is not visible from the rim. We have been monitoring the movements of 133F/187M closely with GPS data as well as radio telemetry, and this first time pair is showing strong behavioral traits that a nestling condor is still being visited and fed. In fact, we have found out that this actual nest cave is visible from the north rim of Grand Canyon National Park, but only for a few hours in the morning, as the sun and shading distorts the field of view, which is 8.8 miles away direct line-of-sight through a high powered scope! Through this method of monitoring, we have noticed the pair making very brief and frequent visitation to the nest cave after leaving local carcass locations, then leaving the nest site and roosting close by. This also is a great indication that the adults are tending to a very hungry and food-demanding chick.
Examining the failed nest cave of Condors 195 and 158.
The Vermilion Cliffs nest sites (126F/114M and 195F/158M) have been a bit more variable. After assuming that Condors 195 and 158 were tending to a chick near our release site, the pair made an abrupt shift in behavior over a three day period that resulted in vacating the nest cave. With eager hopes of learning the cause of failure, crew member Evan Buechley and I made the climb down to enter the nest cave and search for any clues. Unfortunately we found nothing—no chick, no egg, not even any eggshell fragments. So based on behavioral trends and proximity to the release site, which can alter typical nesting behavioral patterns, all we are left with are assumptions on what “could have” gone wrong, and hopes that the pair chooses a different location next year; hopefully one that is a bit farther from the constant activity of the release site.
Condor 114 soaring with a full crop.
Feeding, frequency of visitation, and roosting trends all lead us to believe that the veteran pair of 126F/114M has successfully hatched a chick, and continues to feed the now 19 day-old nestling. Remember that this pair fledged Condor 389 in 2005, Condor 459 in 2007, laid one egg that later broke this past spring, and then recycled and produced another egg (hopefully to hatching on 20 June). So keep your fingers crossed that these nesting pairs succeed in fledging young, and stay tuned to next month’s NFTF for more updates. Until next time…
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