And I Thought Sparrows Were Tricky: Handling North America's Largest Land Bird
Although my California Condor internship ended almost one year ago, I still often think about what an incredible experience it was to handle the giant birds.
With this blog post, I hope to paint a picture of what biologists go through when giving much needed medical checks to California Condors, a highly endangered species. Before I do, I'd like to discuss some background.
The California Condor was one of the first species listed on the Endangered Species Act of 1973. This species once ranged across all of North America, but was extinct in the wild in 1987. At that time, only 22 individuals existed, all in captivity. Through the incredible efforts of biologists, there are now about 270 in the wild and another 170 in captivity. Despite the tremendous growth in population over the past 30 years, the species is still critically endangered, meaning California Condors will face extinction without continuing human intervention. This includes the biannual health check of every wild California Condor. I was lucky enough to be an intern during the spring health checks in Big Sur, allowing me to get up close and personal with these massive creatures.
So why do California Condors need a health check twice a year? The short answer is lead poisoning. Condors ingest lead fragments when eating a dead animal shot by a lead bullet. Although lead bullets have been banned in California, the legislature will not be fully enforced in California until 2019, meaning hunters are still able to use lead bullets when hunting certain game in California. Until 2019, condors in California will continue to ingest lead and some will die from the poisoning. For this reason, each condor's blood is checked for their blood lead level twice a year. This test is conducted in the field, allowing biologists to take immediate action if their blood lead level is above a minimum amount. Intervention at a zoo is needed where the condor can undergo a procedure to counteract the affects lead has on the body. The condor is released back into the wild once the lead is cleared from their system.
Catching a wild condor is no easy task. This is North America's largest land bird. They weigh around 20 pounds and have a wingspan of about 8 to 10 feet. Their powerful neck, head, and bill have evolved to rip open animal hides, meaning biologists must keep careful control of these powerful birds during handling. The species depends on the survival of each individual, meaning biologists must take care but work quickly to capture, check, and release each bird.
The capture facilities include a holding pen, a trap, and a blind. This is strategically placed just downhill from a major feeding site, known by every condor in the flock.The holding pen is a pen similar to a bird pen one might see at a zoo. It has a water source for drinking and bathing, perching spots, and a scale so biologists can monitor and record each condor's weight. The trap is essentially a small pen connected to the holding pen by a door that can be raised and lowered by a system of pulleys operated from inside the bind. The trap also has doors that can be opened and closed that lead to the outside. A blind is a small building used by biologists to observe animals. In this case, the blind is used to operate the doors of the capture pen and to document the behavior and weights of the captured condors in the holding pen. The blind is also the location used to perform the health checks. Blinds are notorious for being hot, dark, and cramped. Most windows in the blind are actually one-way mirrors, allowing biologists to view the condors while maintaining a human-condor distance. Although biologists are expected to stay in a bind for many hours, the only restroom facilities include a bucket placed in the corner of the room. If they can hold it until a strategic time, biologists may be permitted to squat outside behind the blind instead of using the bucket. Biologists are only permitted to enter and exit the blind in the morning prior to capture, directly after a capture, or once captures have concluded for the day. This is to minimize the human-condor interaction and to minimize scaring condors away from the pen.
Catching a condor begins a few days prior to the planned health check day. The pen is prepped a night before the first morning of captures. The bath, and main water source, in the holding pen is cleaned and filled. Food is placed just outside and inside the trap. This is to attract the condors down the hill and towards the pen. All materials needed for the health check are placed in the blind attached to the pen. The pulley system inside the bind is tested and the door tracks are inspected and any debris that may impede movement is removed. The doors leading to the holding pen are closed and the doors leading to the trap are left open. Food is placed on the slope of the hill, leading towards the pen. A large amount of food is placed just outside the capture pen and in the center of the pen.
Capturing condors can take place over a number of days, always beginning before sunrise. In the summer, this means arriving in the blind attached to the pen at around 4 am. Once in the bind biologists must remain silent and wait for the first condors to approach the pen. Once they do, biologists keep track of what condors are in the area by recording the number on the condors' tags every half hour. This can get tricky as many condors like to hang out on the roof of the bind or just out of view. The condors due for a heath check are listed on a sheet of paper that biologists keep checking to determine what number of wanted condors are in the area of the pen. It may take hours before any condor enters the trap and once they do, things become much more interesting. It then becomes a waiting game for the ideal condors to enter the trap before closing the doors. Once the doors are shut, any condors in the area will fly away, making it more difficult to capture condors again that day. It's a good idea to wait until about three or four of the ideal condors are in the trap before closing the doors. This rule is broken when a particularly difficult condor enters the trap. This will be a condor that has evaded capture when it was due for heath checks in the past, one that has a broken transmitter, or one that has caught a biologist's eye for another reason. Closing the doors of the trap means that biologists may capture some unwanted condors. These are condors that had already had their heath check. Freeing these condors while moving the wanted condors into the holding pen becomes a quick game of pulling leavers and hoping for the best. It may take four to six hours before the first few ideal condors are caught for the day and the process continues. Often times, biologists will rotate out or stay in the bind until dusk. Depending on which condors are captured, the process will continue the next day or two.
On the day of the heath check there will be a number of condors in the holding pen. The number depends on the amount of time and biologists allocated to that particular heath check day. Often times, biologists from other facilities will travel to another holding pen to perform heath checks on their birds that may have traveled to a different area.
Once biologists are ready to begin a health check, one or two condors are removed from the holding pen and taken into the blind. This can be a hectic process, usually involving a number of biologists opening and closing doors strategically or biologists entering the holding pen to coax condors into the blind. This is when the human-condor distance is breached, and biologists must physically handle the large birds. A large net, similar to that of a giant butterfly net, is first placed over the condor to keep it in one spot. A biologist then kneels on the ground with the condor's tail firmly between their knees. One leather gloved hand is paced over the condors powerful bill on the outside of the net. The other head is placed under the net, slowly moving up the condor's back towards the bill. This hand then takes control of the bill under the net and the other hand then works under the net and body of the condor. The biologist makes sure that they have a secure grip of the condor's bill in one hand and of the condor's body and wings in the other before asking another biologist to remove the net from the condor. The difficult part is then standing with the bird and moving into the blind where the health check will commence. Another biologist takes hold of the condor's legs and tail firmly between both hands, and both biologists will sit side by side on a bench. The health check can now take place.
A third biologist will begin the health check, often times with the help of a forth biologist. One condor leg is first cleaned and blood is drawn. A field blood lead level test is carried out in the field. This usually takes a few minutes to complete. If needed, the condor will also receive vaccinations, a new transmitter or tags, and may have flight feathers counted and measured. If the blood lead level indicates and unsafe level, the condor is then placed in a large kennel to be transported to a zoo for treatment. If the condor has an acceptable blood lead level and there are no other issues, the condor is released back into the wild. During the health check, the condor will struggle. Both handling biologists must maintain control of the bird to ensure safety, especially to the biologist carrying out the health check. It is also important to keep the condor cool by placing a wet towel over the condor's neck and legs.
Releasing the condor is an amazing experience. Once ready, both handling biologists stand. When the main handler has complete control of the head and body, they will ask the other handler to let go of the condor's legs and tail. The handler will then walk outside the blind to the side of the slope outside the trap. Releasing the condor is as simple as opening both arms quickly and watching the bird hop off the slope and fly and into the sky.
All images in this blog post and the video linked here belong to Tim Huntington.